HDMI to Old CRT

[abstract3000]

Greetings,

I have a MAME Cabinet built over 20 years ago that used to sport an old PC with a GPU that had S-Video Out to an old Sharp 25" CRT. The HDD was 20GB if that gives you an indication of when it was built, late 90's?

Well the cabinet is in great condition all wired up to an I-Pac and Opti-Pac but has been sitting in Storage and now in my garage with a cover over it for years. I decided this years winter project will be fixing it up and getting it working again. So I'm beginning the Research phase now. I started out buying a Beelink mini PC w/ Windows 11, loaded Hyperspin frontend on it and the specs for the Games I have installed run without any issues so I Would like to continue with the hardware only problem is it has 2 HDMI outputs and no ability to install a GPU.

I had a look over this long thread of information: https://www.aussiearcade.com/topic/76809-a-guide-to-connecting-your-windows-pc-to-an-sd-crt-tv-pvm-or-arcade-monitor/
And from What I gathered I need:
- Groovy Mame
- Tendak AV-107-BK
- crt_emudriver (If even plausible with Windows 11, might have to get te Windows 10 Install)

Though after that point I am going from Digital to VGA, the TV has S-Video Input as well as standard Composite Yellow Input so would prefer the S-Video do I just need a another adapter to move from VGA to S-Video? Is there a particular device that might serve better than others? Or am I way off?

[buttersoft]

Hey there, i've edited the info on converters in that guide as it was a bit out of date, sorry. The Tendak isn't great, i had better results with cheap converters. And someone has been doing a chunk of testing.

https://docs.google.com/spreadsheets/d/1nbepvFFBVsLrs1myOiVWqMVLp9-oB9TataRmVlcyqlA/edit#gid=0
and notes for the above
https://docs.google.com/document/d/1Fz3OfWZgftiTfqG-_JCBJku4a0qzDZeWzmEk4S3Iyjk/edit#heading=h.8c2nlbp9r33g

Ok, so the core of that guide is still solid. To connect to an old CRT TV you need to deliver a 15kHz video mode. Think an SD NTSC/PAL image or close to that. Your PC is not going to be able to output 15kHZ without special tweaking. Sections e) and f) of the guide cover this.

The cheap and simple solution is to go an HDMI-to-AV box for a few dollars from ebay. It'll work, but the results are far from optimal.

I would recommend reading the guide again, from the start, and going over what it says. All I'd be doing is writing out the same things here, but feel free to ask specific questions

After reading the guide you will hopefully be able to say:
- how you intend to get a 15kHz signal (straight from your PC, or via a downscaler/converter?)
- what input signal plugs your CRT has
- how you will get whatever signal type the PC outputs into the TV (just with a cable, or do you need to convert? A downscaler/converter will probably do this, but not always)

Once you have an image on the TV, then, and only then, you think about setting up your emulators.

[Zebidee]

Just like there are many ways to skin a cat, there are many (well, a few) ways to do this.

If it was me, I'd try modding the TV to take RGB input or, failing that, component input.

If soldering irons scare or bewilder you, then you could try using a transcoder to convert RGB to s-video, such as the JROK. Be aware, as Butters has already foreshadowed, some "adapters" are shite. Butters' updated guide should hopefully give you some other tips about quality transcoders.

Then, with a computer and *compatible* video card, you can use Calamity's CRT_emulator driver & software to get 15khz RGB out.

For your old IPAC, you may need to find/download the legacy utility from Ultimarc.com

[abstract3000]

@buttersoft

Thank you for the Links of Adapters, and pointing at the fact the Signal needs to Be sent at 15khz and Stay 15khz, so upon re reading everything a bit closer and further research this is what I have came to understand.

My Beelink with Integrated Intel UHD Graphics isn't going to work with Windows, so that option with Hyperspin is really not a viable option.

Instead it appears I will need to load a Debian Linux distro and possibly a Patched Kernel onto the Beelink and stick with something like Attract Mode instead, to give myself more control over the output of 15Khz.

On top of that due to it being Intel UHD I will have to output a bitclock of at least 25mhz meaning I will need to use Super Scanline configurations but also multiply the horizontal scan lines by like 8 times.

From that point I will need to pick an HDMI to VGA adapter from that list you provided a link too, and from the VGA to the SVideo I will need a Device that passes through the signal rather than trying to convert it to 480i, While I did notice the Jrok adapter people keep discussing that needs the VGA Output to be split into Wires for and pinned RGB to that board which seems a bit messy, whereas this device on eBay https://www.ebay.com/itm/355013147622?hash=item52a86ebbe6:g:Ld4AAOSwlVFk8qvg&amdata=enc%3AAQAIAAAA4GLBB5IugGJLuygkC%2FKtWGAIyXu%2BUqegqVp5rx4bD3Nd22nt9CNL1LxOorVoiQv%2Fm45dsGcssLhcuz3gfToca5g5%2F%2BTOZi9O8F%2FdAJnxpnYQbH9%2FdrAbDW%2FcHcYGG0Gy75tkBSnPkiWz%2Bz8MxYCJv1dXLshyRZvU34qAiHEHbF0mxbKCpbtYXK7viym08UjOGY6rkUnEzZUlildY6B8CqEVxpJVDuAR2Py2kxTg9Uo%2B9lHSJi30askvB57vzAFghTfkS%2FSucdX7yedcF3h0rIuB4L3pxOGmeAqkCB9vkirDW%7Ctkp%3ABk9SR9z1yK3PYg seems like it would serve the purpose and keep everything at 15khz the entire way through?

@Zebidee
I appreciate the Input, but unfortunately it seems the issue takes place before I even get to the CRT in getting the signal to output at 15Khz so I will look into RGB options, I have a very nice soldering Rig in my shop, and feel very comfortable soldering small components, though I do get hesitation around trying to solder individual pins off of an IC Chip.

Though I will consider looking into the CRT Hack for future connections, if this all proves to be too annoying, it might assist in my just throwing in the towel, wiring in a jamma harness and putting in the Game Elf I have had lying around here for years.

[buttersoft]

That item you link to on ebay is a downscaler, with a list of input resolutions and a single, fixed output resolution. It's not a 1:1 converter. The terms VGA and CGA can be a little loose but with that listing VGA is 31kHz, CGA is 15kHz. Sadly the link above was mostly HDMI-to-VGA, nothing much to do with S-video.

I don't know much about linux or getting it running for 15kHz. You might look into Groovyarcade, on the GroovyMAME subforum on here. Substring is the guru for that.

RGB modding is not terribly hard, but like a lot of things it's daunting to start with. There is an excellent thread on the Shmups forum about modding TV's to take RGB input. It's huge and detailed, but all the info you could possibly want is on there. Be prepared to do some reading, and when you know enough to ask specific questions, go ahead

[abstract3000]

So after allot of reading, it simply appears there is no Viable option to Go from the VGA port to the S-video Port keeping the 15khz intact.

I looked over the Sharp CRT I have and since the case was tossed with the manual more than 20 years ago there is no label/Sticker or Printing that indicates the TV's actual Model Number that it was, and every number i get from the board and tube I throw in google and get nothing, so without a way to get ahold of the service manual and layout of the board, I don't intend to go back for an Electrical Engineering degree to reverse engineer the board to wire in RGB Scart plug, I think this is going much further into something I'm simply not that interested or dedicated to as I was 20 years ago when I built it. I am just tired of having a large cabinet sitting around doing nothing.

I decided for the time being going back and doing what I know works, So ordered an older motherboard that accepts the 16GB DDR3 I have sitting around with an i5 Quad Core Chip and PCIe 2.0 Slot on it, To go with an ATI Radeon HD 4890. This way I know the CRT Emudriver is compatible, The card has an Svideo Port to go directly to the CRT and I will just Use Windows 7 Pro with Hyperspin and the MAME set of 800 Games I procured and have everything working I had envisioned. I am not trying to emulate all sorts of systems, just the basic older MAME games, and the Specs on the build are more than adequate to Run.

I appreciate all the input and pointing of resources, as that initial Guide will come in to handy I'm sure when it comes down to passing the connection through, unfortunatley I will just have to put the Beelink aside and put another Caged PC Case below

[buttersoft]

A J-rok will convert Arcade RGBS into S-video, i believe. There are other options too, but it's been too many years since i looked to remember models or even brand names.

A GPU using S-video out does not require crt_emudriver, but it's still a good option, as any official driver is going to be equally ancient and possibly unhappy on modern Windows.

TBH you would want to get a Radeon HD 5000 series card or newer (but still on the crt_emudriver compatibility lists) as the 4000/5000 divide is where newer drivers and EDID emulation kick in. That said, i understand you want an S-video port as a back, which is not unreasonable.

As a last attempt at using this TV for RGB, you might see if there are markings on the two or three largest computer chips inside the TV (on the chassis, which is the common term for the big PCB inside a TV). One of those chips should be the micom, or microcontroller for the on-screen-display (OSD). The other should be the chip you want, generically called the jungle chip, which is the video and scan controller and might show RGB inputs. Normally you get the TV's service manual, which in many cases leads you to googling the jungle chip anyway. If the set is from the late 80's onward, you will almost certainly be able to RGB mod it.

If you're really looking to get something running using the Beeline, you could always go  something like one of these for S-video - https://shorturl.at/aEQV2 and then you go get any cheap HDMI-to-VGA converter if you need to do that. Whether that's going to be any better than a super-cheap HDMI-to-AV box IDK. You might ask on the CRT Collective or other facebook groups about recommendations for a cheap converter.

[abstract3000]

So the Jrok Adapter I assume you are talking about is this: https://www.jrok.com/hardware/RGB.html

Then I would need something like this Cable to go from VGA to that Board https://www.ebay.com/itm/265683088475?hash=item3ddbf2345b:g:8HoAAOSwAiRid~-o&amdata=enc%3AAQAIAAAA8HocyvfvM65WfiZLiMY4M1zbccvNQ2B8Cr6WX51NIXZ%2FkYNZyjSKCVus%2BwB%2FcNpBXe140WQDhyB%2BSjg7aRdNzcu3gbWyr1Ljfq7AE6f6iHIzlzuz8aNtQKf2Jv7%2FHR3s5pdRNRheiprBJ1hd2usY3j8SLzhoDA8i6pmV%2BvuuYf0jr%2BDvEFmNpiI%2Feae4PSzqKjEC1TaZQ%2F2n54T8czsT%2BLEMbzyqDM0EpIr4AnSeSQjfRQTX58S3VrKpFgRzFetYBGhvWrPzqOMDanA427u63bOlQ9Qat4X%2B00MBpFnhDaLYXuD%2Fna2TshfFSpISBUOU6Q%3D%3D%7Ctkp%3ABk9SR_agkJrQYg

And some sort of Plastic terminal to connect the wires in to plug over the pins? That was the only thing that seemed to look like it might work, everywhere else stated that I would need a Transcoder of sorts yet nobody in all the threads I have read was able to name a single one that was still being manufactured.

I dusted off the CRT some more and found a sticker with writing on it and what appears to be a manufacture date and what I think is the model Number 27RS100, I can Find the Manual for Sharp 27RS-100, I have 1 Single long Rectangular IC Chip (I didn't count pins) on the top Side It is: SHARP X3354CEN1 1JDH
on the bottom side of the PCB I found 2 Square IC Chips, Sony CXA20740 & IX3528CE.

I found someone who posted on Reddit about an RGB on a Sharp 27L-S100 (Not sure the difference between the R & the L) posted a Diagram with 2 IC Chip Number neither matched anything I saw on my board and no real pictures of the mod itself so have no clue if it would be the same or not.

[Zebidee]

I looked over the Sharp CRT I have and since the case was tossed with the manual more than 20 years ago there is no label/Sticker or Printing that indicates the TV's actual Model Number that it was, and every number i get from the board and tube I throw in google and get nothing, so without a way to get ahold of the service manual and layout of the board, I don't intend to go back for an Electrical Engineering degree to reverse engineer the board to wire in RGB Scart plug, I think this is going much further into something I'm simply not that interested or dedicated to as I was 20 years ago when I built it. I am just tired of having a large cabinet sitting around doing nothing.

Sharp, like every other TV manufacturer, used the same chassis (with variations) in many different models. There will almost certainly be a manual/schematic out there, you want to identify the chassis model number.

As an intermediate step, try to identify the jungle chip number, then search on that for a datasheet. Jungle chip is usually pretty easy to identify as is usually the largest, and will have video signal inputs and RGB outputs. Then finding the OSD chip should be easy. This, and a good look over the chassis to find where the inputs and outputs are, will give you most of the information you need.

In most cases there will be no need to solder anything directly to a tiny IC leg - there will be more convenient places to hack signals into, like a capacitor or resistor leg or similar on the input line.

Not wanting to disagree with Butters, but I've found that some later model sunset-era (~ late 1990s or 2000+) CRT TVs use large 64-pin jungles with no RGB inputs, and the OSD (on-screen display) functions fully integrated. You can't directly RGB mod these without going directly into the neckboard (but it can be done). I have a bunch of these TVs, but mostly I just component-mod them and then use a GreenAntz VGA RGB-component transcoder (BTW I design/make these, but they don't do svideo).  However, I think that for the early 90's Sharp TVs, inputting RGB via the OSD would likely be the best way to go.

You don't need an EE degree for this stuff. I certainly don't. Just a decent brain and basic electronic knowledge. However, if still reluctant, a more practical option might be to find someone local who can do the RGB mod for you. Try the Facebook groups Butters mentioned.

I decided for the time being going back and doing what I know works, So ordered an older motherboard that accepts the 16GB DDR3 I have sitting around with an i5 Quad Core Chip and PCIe 2.0 Slot on it, To go with an ATI Radeon HD 4890. This way I know the CRT Emudriver is compatible, The card has an Svideo Port to go directly to the CRT and I will just Use Windows 7 Pro with Hyperspin and the MAME set of 800 Games I procured and have everything working I had envisioned. I am not trying to emulate all sorts of systems, just the basic older MAME games, and the Specs on the build are more than adequate to Run.

This is really the best approach, new PC instead or trying to retrofit the Beeline, except I would go for a HD5000+ card as Butters has already suggested. I personally don't believe it is worth pursuing a card with s-video output - the quality will be poor and unsatisfactory. That is not a criticism of svideo, but rather then cards will just squish your video mode into a NTSC standard interlaced mode, probably 720x480i. It is OK for video content (like, showing video or powerpoint slideshow at an education/training workshop), but will be very mediocre for gaming. You would be better off with RGB output from the computer and a transcoder.

If you still want a card with s-video out option, then just buy another card to keep in reserve - they should be cheap enough. The "converter" Butters linked above will also give you svideo, but they are mediocre quality, much like I described above (I have one that is basically identical). Something like a JROK should be better (if your TV does NTSC - an Australian friend of mine recently told me that he tried to use a JROK/svideo with a PAL TV and it simply didn't work  ).

EDIT: I was about to post but then saw your update, so added a little below.

You can make a VGA breakout cable from an old VGA cable.... or buy a new one, should not cost more than $10. I've even used old cables cut off back of old monitors.

Then buy yourself the female headers to plug into the JROK pretty easily:
https://www.ebay.com.au/itm/194389582822?hash=item2d4285a3e6:g:zbgAAOSwql5hTZ34&amdata=enc%3AAQAIAAAA0IU%2B0PWunJ58ET4r7NTOqar6Kw35Ibjb%2FDB8nHzJ0eXT5gXmuDvN7fvEf8OQAjwvvVguClXbIzPssmv3gO9upT5hR%2F0G%2FdBhfUZDIUvmBFesLsM4jo%2FpG%2FYDlDro2jfioSjIbXAoyBN8mkhKF%2FAeasxjJzMWMhamxmcrxyNKR8fgSNU9o6I8T0TjdL1mQdbmfO%2FLkn0KWMOdPGyuxm6FCyxbkT5mMBgOvz%2Fe%2F1b9lLAKMgchgbd5BadLe%2FedD9qgJ4%2BygSatloI0geGr8wAORlA%3D%7Ctkp%3ABk9SR-SxvJvQYg

You can also find those headers available in kits with a bunch of different sizes. This may be a better option:
https://www.ebay.com.au/itm/353414711625?hash=item5249288949:g:MkgAAOSwaRhgR0IU&amdata=enc%3AAQAIAAAA0NygcXeXY6vjpna%2BIMVHGgpHZKLPGpe58Y%2BQQIMla4lSOQbbBQxW3%2FOW708sIuwUHaqgCODCGNiuhpjHm7v52JiJ%2BBSflA9aPUSRziGJ21M7K8o5qJBbwWfgTfBBhComh%2FfheBkgYicmqPX4Pn7WLy0oR0mXOoxzAkRhtVF7sPZoZy5aOjpnGwJMKP7c7eXQ8E3XPyYUtl8pezaRopn7cQXG5%2F0PNkplGIcYM9uPR66kzzUAU5la9a%2Fw7JXwHCJDJDN6WqPGKeoTECPHlF2LUnk%3D%7Ctkp%3ABk9SR6qQqZvQYg

Search for "PCB header connector 6 pin 2.54", and also get yourself a reasonably priced crimping tool.

[Zebidee]

I did some quick googling with the extra info you provided.

According to berrmal64 on this reddit thread, the Sharp X3354CE... jungle is really a rebadged Sanyo LA76843N

Click here is that datasheet.

Someone has already tried modding your model TV on the Shmups RGB mod thread. MarkOzlad (I know him and he knows his stuff) also confirms that is uses a rebadged Sanyo jungle.

You can find a manual/schematic here. It seems like it is just a "supplement", but it has the essential info. I can see the OSD RGB inputs and there is a 5-pin header that you can probably tap into.

I've already attached the jungle datasheet for your convenience, but the schematic was too large.

[buttersoft]

Not wanting to disagree with Butters, but I've found that some later model sunset-era (~ late 1990s or 2000+) CRT TVs use large 64-pin jungles with no RGB inputs, and the OSD (on-screen display) functions fully integrated.

Yeah, that's a point. I have encountered a TV like that, but only one. That said, i'm poor so i have to live in Tasmania, and maybe fewer of those fancy TV's were imported from Victoria

[Zebidee]

Yeah, that's a point. I have encountered a TV like that, but only one. That said, i'm poor so i have to live in Tasmania, and maybe fewer of those fancy TV's were imported from Victoria

May have mostly been for the Asian or developing country market, where the CRT sunset phase lasted a little longer. Most notably the "China TV" chassis and I've also seen similar PCB layouts in other local brands like Toshiba, TCL, Samsung TVs. I've see them a lot in Phillipines, Malaysia, Thailand, Laos, Indonesia, India... to name a few. Often flat screens, but not always.

I can imagine, not many managed to get to Tassie.

Haven't been to all those places on a CRT tour, some I guess, but I have watched an awful lot of repair YT videos for these in Tagalog, Bahasa, Hindi, Thai etc. I do speak Thai/Lao of course, but for the other languages is a lot of guesswork. Tagalog & Bahasa are not too hard to guess at. Almost nothing in English, and when it is the accent is usually so bad I prefer the Tagalog. Fortunately electronics is all the same language, lots of diagrams, pictures and pointing at things helps.

These all-in-one jungles were used in name-brand TVs originally, think Toshiba is the main IC manufacturer but used in sunset Sony, Samsung etc too. From what I've seen.

Anyway, by rolling the OSD (and maybe some other functions) into the one jungle they saved a few dollars. It is essentially a little CPU and the BIOS is stored on a smaller EEPROM chip nearby. You can even re-program the BIOS if you want (I hacked mine to float "GREENANTZ" across the screen instead of the TV brand name) and the service mode is very useful. The chassis's are relatively simple. I think it all came down to reducing costs. In the case of the "China TV" chassis, they are often used with donor tubes to save costs even more. Where do you think all our electronic recycling was going when were shipping it all to China for decades? You can still buy back "new" CRT TVs with a truly new "China TV" chassis and a refurbished tube on Alibaba.com. If you're really lucky the tube might have originally come from your Grandad's old TV.

Anyways, all a bit off-topic, @Abstract's early 1990's Sony appears to have RGB injection via OSD available.

[abstract3000]

Thanks Zebidee for all that info, If nothing else it gives me a Place to Start and a couple individuals who might be able to assist along the way. I did however notice the  Service doc you posted I don't think applies to my TV, I have a 27R-S100 & that manual covers a 25R-S100 ? (maybe they are the same...) I will have to disconnect and dust the PCB off an take a look. I did however see a couple YT videos describing the theory in graphical representation that helped a bit, but we will see How it goes. I tried searching to see if there were any modders providing the service that I could pack the PCB up and ship it too, but that appeared to be a no go, maybe not searching hard enough.

In the meantime from a few different threads from the last couple years I saw and no response from my email,  it appears the Jrok adapters are no longer being made. I found what appears to be similar to a clone in Australia https://www.converters.tv/cga_to_pal/RGB-to-Video-Converter/68.html

If it is, and I can get my hands on it then I could simply use it in conjunction with an Asus AMD Radeon HD 6450 (VGA -> Converter Board -> S-Video), So I will see if that option is available. If it turns out to be another dead end, I will go with my original plan for the meantime with the HD 4890. I will continue to pursue the CRT Mod option so any GPU with a VGA will give me the ability as it would make the CRT Future proof as well and overall better option as finding a 27" Wells Gardner would be slim to none in my neck of the woods. Though if for any reason I can't get the CRT mod done, I'm not going to just let the Cabinet sit around with nothing in it for another 10 years, I need some sort of usability out of it, and even if it isn't the best looking, I never complained or saw anything that bugged me previously when it was set up that way.

[abstract3000]

Ok so change of plans... I reached out to an old Friend who I haven't spoke to in years, who used to be a coin op back in the 80's and owned an Electronics Repair shop before retiring, I asked him if he knew anything about modding CRT, he had in fact done it and was able to pull the schematics for my Model and stated he would be willing to do the work. So in the meantime I will be having the TV RGB Modded, but was curious most people are wiring into a SCART plug, (I'm in the U.S, not sure if you are aware but that type of connector simply is non existent here) there is also the female terminals we are used to seeing, what would be the better option for overall compatibility going into the future? I guess his thoughts after speaking more to him was to add a CGA D9 plug apparently this is what Most arcade Monitors have

[Zebidee]

There can't be much difference between schematics for the 25" and 27" models, and definitely the same jungle. Even when you have the schematic there, you need to look over the TV chassis itself because there are often manufacturing differences.

Glad you've found a local friend to help with the RGB mod.

That converter you linked looks interesting - note that you'd need to provide a power supply ~12v. An old power brick should do the job, or a standard arcade DC power supply. You can solder/connect the supplied cable+plug to it. Seems well suited for use in an arcade cab.

SCART is the RGB standard input for CRT TVs in Europe, that's why many people use that connection. However, there is no need for you to copy. I (and many others) prefer to use a VGA D15 for RGB. That way you can use a plain old VGA cable to connect with your computer. The connector is also more secure, I've always found the SCART clunky. The VGA jacks are both cheaper and smaller, and easy to screw onto the back/side of a TV case.

I like the HD6450 cards - I have about five or six, couple of different brands but very similar. CRT_emulator installation is very straightforward. I was also able to use ATOM-15 on all of them to mod their video BIOS so that they are 15khz from boot. So, for example, you can access the computer BIOS and boot options using your TV.

[abstract3000]

Thanks again for all the Input, I am going to build a frame out of 2x4's this weekend to remove the tube from the cabinet and mount it into to protect the neck. This gives me the ability to move the monitor to his place for him to work on. I studied the Pinouts for the CGA/D9 & the VGA/D15 and I'm fine with either he decides to wire in there. As both pinouts have the R/G/B/GND/V-Sync/H-Sync connections it will be easy take the connection from point A to Point B and adapters are easy and cheap to come by if needed.

I chose the Asus AMD Radeon HD 6450 because I read somewhere that was one of the creators of CRT_Emudriver's personal video card at the time, so If any card will be compatible that will be one of them, and they are really really cheap. Thanks for the heads up on the ATOM-15 software I will look a bit further onto that. I finally feel relieved I know the path I'm taking, cause it was becoming a serious headache trying to figure out what converter that would work, just to find out it wasn't possible to get ahold of. I know at least know I will no longer be wrestling with the S-Video Adapter.

[buttersoft]

After using RGB, i couldn't go back

Post some pics when you get it up and running! Or come back and ask questions, i guess. To be honest, this isn't really the place for crt_emudriver or GroovyMAME support, the GM subforum is best for that, but there is a monitor involved so i'll call that enough crossover

[Zebidee]

I studied the Pinouts for the CGA/D9 & the VGA/D15 and I'm fine with either he decides to wire in there. As both pinouts have the R/G/B/GND/V-Sync/H-Sync connections it will be easy take the connection from point A to Point B and adapters are easy and cheap to come by if needed.

Whatever way you prefer is fine, but if you go for a female Dsub15 (VGA) port on the TV, you won't even have to worry about pinouts. Just use any common/standard/ubiquitous/cheap VGA male-male cable to connect your computer.

Note that, whatever connection you choose, the separate H+V sync must be combined into a single composite sync for the TV. Your mate doing the RGB modding should be aware of this.

The simplest way is to twist the H+V wires together and run it through a resistor in series (people commonly use values between 470R and 1K). The resistor is to bring the sync voltage from ~4-5v to ~0.3v for TVs. This "smushy" sync that isn't 100% perfect, but will work OK with about 99% of CRT TVs. Most people are pretty happy with this.

An alternative is to run CRT_emulator with composite sync. This is a better quality sync, but for many TVs you might not see any difference. Composite is only output on VGA pin 13, so no twisting H+V together, but you still need the resistor in series. You would want to leave off/disconnect VGA pin 14 (V sync) to avoid ghost signals from leaving it "floating".

You can even wire up your own simple composite sync circuit too, is pretty easy with some cheap logic chips or transistors, but this is probably more than you want to do.

[abstract3000]

I can definitely post photos, there is a lot of blunders in the Case my late teenage brain thought would be ok opposed to my now, and I can give some before and after shots of the monitor, wiring etc. Though for the meantime this is a picture of the cabinet up and running from sometime i think in ~2003?




Thanks for all the Help and More Pics & Questions to Come I'm sure

[abstract3000]

Well got a snapped photo today, RGB done as well my friend added an Auto Power on Circuit to the TV
More photos to come!

[Zebidee]

Looks great!

Simplest way to add an "auto power-on circuit" to a TV is to put a capacitor between the soft power-on switch terminals. When connecting to power, this adds a short delay (typically less than 1 second) before closing the switch. This is usually enough time for the TV control circuitry to wake up, and then being able to register that you've "pressed the switch".

Am I imagining a soft shadow in the middle, between the blocks of red and cyan?

[abstract3000]

well I got the TV back today, and it appears he simply used a board to put everything on, and he gave me the schematics for it as well.  (Ignore my previous squirrely ignorance ) I needed to spend some more time reading up on H-Sync & V-Sync vs Composite Sync....

So with it pinned to analog VGA Layout, a Vga to Vga Cord should work just perfectly I suppose.  When I get the Power Supply In, I will start loading Windows 7 and getting GroovyMame setup with CRT_Emudriver, and we will see how this goes

[abstract3000]

Well it appears my first test of connecting to the monitor is a Crash & Burn no success 

I used Win10 for Testing enabled the TESTSIGNING got the CRT_EmuDriver installed it found my Card and Installed AMD Radeon HD 7400 Series (CRT Emudriver) Drivers correctly.

Opened up VMMaker, (verified CRT Emudriver on the screen)
- Selected Arcade 15.7
- unchecked Extend desktop automatically on device restart
- Dropdown box to VGA_Analog_0
- Clicked on Enable EDID emulation

Unplugged the VGA from the monitor and moved it to the CRT and well.... Nothing :/ Swapped through all inputs which didn't do anything powered the TV on And off and still nothing.
When I moved the VGA back to the Monitor the Screen rez was all screwed up small to the side with lines through it indicating what i guess to be it was outputting the signal at 15kHz. So... Any ideas or suggestions? I have the schematics from the TV to the pins posted above on my VGA pinout, using a standard VGA to VGA D15 Cable.

After reading a bit and looking at my windows display settings i don't see any modelines for 640x480 available... not sure if that's the issue, but I will try to find the modelines to install and see if that option comes available, switch the monitor to that maybe and try again?

[buttersoft]

Sorry to maybe go over stuff you've covered before, but... Is the Arcade monitor known working? Is the setup monitor an LCD or a CRT of some kind? It's really unusual that an LCD would display a garbled image, esp at 15kHz.

[abstract3000]

I apologize for my description of "garbled". The setup monitor is a Dell LCD monitor. When I move the vga back from the CRT to the setup LCD, I see an image of VMmaker software extremely large but offset in the corner and there are tear lines or flashing horizontal lines through the screen until I click on disable edid emulation. And it returns back to normal.

Hope that clears that up, the lowest resolution my current settings support is 800x600 do you not think having the additional modelines installed could be the issue?

[buttersoft]

No need to apologise, garbled is probably fine for what you're talking about. I merely wanted to clarify what was going on.

Not having the modelines installed should not be a problem. Activating EDID emulation will read the monitor preset, and spoof an EDID based on that, so it should be pushing 480i when you do it. I believe you are selecting the right display head of the GPU as otherwise you wouldn't get anything onscreen, garbled or otherwise.

What is the CRT you are trying to connect to? If it's a PAL CRT, you should be using the PAL preset (at least to troubleshoot, which is where we are now). Do you own a multimeter? Most are capable of reading frequency. You could use one to read pin 13 of the VGA output and see if it reads 15kHz. It probably will, which would me it's probably not the PC at fault.

You have the TV working? With RGBS? Or you don't have any other RGBS sources, and you're trying the RGB-mod for the first time with this PC? something isn;'t

[Zebidee]

For whatever reason, the forum site has suddenly decided that I can't see the pics you've attached unless I deliberately download the file and open it in a separate viewer app.

What this means is, commenting on your post, on any post with pics directly attached, is really hard

[abstract3000]

No need to apologise, garbled is probably fine for what you're talking about. I merely wanted to clarify what was going on.

Not having the modelines installed should not be a problem. Activating EDID emulation will read the monitor preset, and spoof an EDID based on that, so it should be pushing 480i when you do it. I believe you are selecting the right display head of the GPU as otherwise you wouldn't get anything onscreen, garbled or otherwise.

What is the CRT you are trying to connect to? If it's a PAL CRT, you should be using the PAL preset (at least to troubleshoot, which is where we are now). Do you own a multimeter? Most are capable of reading frequency. You could use one to read pin 13 of the VGA output and see if it reads 15kHz. It probably will, which would me it's probably not the PC at fault.

You have the TV working? With RGBS? Or you don't have any other RGBS sources, and you're trying the RGB-mod for the first time with this PC? something isn;'t

Ok so The Monitor is an NTSC SHARP 27R-S100

It has never been hooked up to and worked with the PC This is a First time
I know the RGB Mod was done as seen in the photo above that is the monitor, My friend demonstrated the mod with a Sencore CM2125 Monitor Analyzer he has in his shop.
I took the measurement off the Multimeter I get 15.7 kHz on Pin 13, & 60kHz on Pin 14
I tried slightly adjusting Screen Voltage on the Flyback with no Success, but let me explain the following:

When disconnecting the the VGA very slowly I noticed something appear on the screen. I started just jolting the cable around and for the brief Second I saw the image show up on the CRT but quickly disappear. I discussed it with my friend who stated while a loose connection is always a possibility is more inclined to believe my connecting and disconnecting was disrupting the sync lock and i was seeing the image prior to the lock taking place. So he does not know anything about the CRT Emudriver but asked if there was a Way for the Software to Invert the signal for shits and giggles.

Hopefully i have answered all your questions, if not feel free to ask anything else and i will see what info I can get

For whatever reason, the forum site has suddenly decided that I can't see the pics you've attached unless I deliberately download the file and open it in a separate viewer app.

What this means is, commenting on your post, on any post with pics directly attached, is really hard

Sorry about that i was uploading the photos first on imgBB and doing the img tags around the link but they would not show after posting so I started attaching afterwards, I will provide the direct links below to the images

https://ibb.co/q0Wb56L
https://ibb.co/r6mTpwq
https://ibb.co/9w5x8Gy

And here is the img tagged ones let me know if you can see them

[abstract3000]

Well may have solved the issue, I can manage to get the picture on the screen, but not perfect. The black/white/Red/Blue/Green wires on the end appear to be the issue if I touch the resistor next to any of R/G/B the screen shows up in whichever hue I'm missing.  MY friend asked if there was a way to send the Signal via TTL and stated that the circuit was built for sending to a CGA monitor :/
So if the software cant bend to that spec, he would need to redesign the board at best removing the resistors and decoupling caps..... Though he has to get the PC and try and figure out what kind of Signal is being sent from the Video Card, I didn't seem to see any documentation on it but i will keep digging.

[PL1]

And here is the img tagged ones let me know if you can see them

To embed the image in your post, you need to use the actual image URL, not the page URL.

On the page, right-click on the image thumbnail and open in a new tab.

For example:
- The first page you linked to is https://ibb.co/q0Wb56L.
- The image that page's thumbnail links to is https://i.ibb.co/1sdH6cY/crt.jpg.
- Put that image URL in IMG tags like this . . .

Code: [Select]

[img]https://i.ibb.co/1sdH6cY/crt.jpg[/img]. . . and you get the full size image like this . . .

. . . or add width and/or height in pixels to scale the image. (readers can click on the image to blow it up to full-size.)   

Code: [Select]

[img width=350]https://i.ibb.co/1sdH6cY/crt.jpg[/img]

That said, it is better in the long term to upload images either here in your thread or -- the preferred approach -- upload them to the latest stickied "NOT A PROJECT" thread at the top of the Project Announcements sub-forum.
- IIRC Saint backs that thread up separately from the rest of the forum so the rest of the backup runs more quickly.
- Many great project threads have been rendered almost useless due to image hosting companies either going out of business, or changing their terms of service, or moving to new servers, or sites being hacked by spammers, or . . . .


Scott

[Zebidee]

Thanks for sharing that schematic.

The LM555-based timer circuit is an interesting approach. I've achieved same effect by simply using a capacitor (say, 100uF) across the TV power button terminals (you can also add a resistor in series to increase the delay). However, the timer circuit is elegant and may work in situations where the cap trick won't.

Concerning the RGB input lines... I guess those 1.3k resistors are part of the OSD-MUX RGB mod. I'd normally expect to see those 100nF caps AFTER the resistors, and physically as close as possible to the jungle/OSD IC. I don't know why they are on that input breadboard and before the resistors. However, for all I know, there may be extra caps inside the TV as well, closer to the IC. 

That circuit to combine the sync... basically just an NPN transistor, which will give you AND logic sync. This is probably OK for games at 240p and other non-interlaced video modes, but not so great for interlaced modes (like those you typically use for the PC's desktop). This is because it'll lose all the horizontal timing pulses that are normally expected during the vertical sync interval. Some TVs can't actually lock on properly without them, at least for interlaced modes. It also won't work with anything but negative sync on both H&V.

Even if you just twist the wires together you'll still get those horz timing pulses during the vertical sync period, but their polarity will be reversed

So, there are other options to try for the sync, including some that are quite simple (e.g. generating composite sync output via VMmaker).

If you want to know more about sync variants, I suggest you have a look at this blog post from Ste of Retrovision.

Also, VGA sync voltage will be too high for TVs, and there is nothing on the sync lines to pull the voltage down except those 100ohm resistors, which are not sufficient.  You could put another resistor in series *after* the transistor, say ~470R/510R/680R to pull the sync voltage down from ~4-5v to something like the ~0.3v expected by TVs.

Lastly, the blanking signal appears to be raw 5v inserted directly. No diode or current limiting resistor or anything? The TV only has to detect the voltage. Another thought: often there are multiple blanking voltages for different modes. TV might actually be happier with something like 3v. Modders will often put in a basic voltage divider, involving a potentiometer, to "tune in" the blanking signals. Once the needed blanking voltages are known, the pot can be replaced with permanent resistors.

For convenience, I've linked the schematic below.

[abstract3000]

@zebidee thank you sir! I greatly appreciate the time you took to provide that feedback. My friend set this up apparently to act as a cha monitor like the original arcade ones without truly understanding the context I suppose in which the monitor was being used.

If I used crt_emudrivers csync option would that just entail disconnecting the h&v sync and leaving the pins 13 &14 with nothing attached?

If you have some ideas on how to approach the synch issue I could scan the actual schematics for the television and upload them for you to view?

Again thank you so much for taking the time

[buttersoft]

Composite sync from crt_emudriver would be delivered on VGA pin 13. I think, based on the above, you'd just bypass the H- and V-sync combiner circuit and feed the c-sync directly to the TV

[Zebidee]

Composite sync from crt_emudriver would be delivered on VGA pin 13. I think, based on the above, you'd just bypass the H- and V-sync combiner circuit and feed the c-sync directly to the TV

Yes, do exactly this, except feed the composite sync from pin 13 through a resistor (1 suggest 1K, but really anything from 470R to 1K should be fine). Then disconnect pin 14 altogether, otherwise you might get ghost signals. This is the simplest neat solution.

If you want to get fancy, or your friend does, you could try this XNOR composite sync circuit by Tomi Engdahl.. It only needs one quad-logic chip (four XOR logic gates on a single chip), a couple of caps and a couple of resistors. There are a few circuits on that page, so I've linked to a pic of the one I mean below.





Ste (Retrovision) also suggests a good/simple XNOR sync circuit in his blog article (linked above) using 3 different logic chips. This definitely works well, though I'd suggest some decoupling ceramic capacitors (100nf on H, 1uF on V) in series on the H+V sync inputs, and similar value bypass cap(s) for the +5v Vcc inputs (bypass caps, between Vcc and GND, help stabilise the voltage supply).

As suggested above, add a ~1K resistor in series to the sync outputs of whatever option/circuit you use, to pull the voltage levels down to ~0.3v for TV.

If you want to be really clever and make the sync even tighter, add a schottky diode (IN5817, IN5818, IN5819 all good) after the resistor, between the sync output line and GND, in reverse-bias orientation (anode to GND, cathode [end with stripe] to sync). The diode will "clamp" the sync to GND, effectively giving it a reference and making it more stable. Some won't bother, but the diodes are cheap and I find it can help in some cases. I suggest schottky diodes as they are good for fast signals and, being germanium based, have a convenient voltage drop of ~0.3v.

Can draw my suggestions onto a circuit diagram if you are seriously interested.

[abstract3000]

@Zebidee or @buttersoft

I find myself in between a rock and a hard place, as I sit as the middleman passing information between them with my knowledge painfully lacking.  I have a friend who knows electronics and can do what's asked, but may not necessarily understand the context of what's being asked or what's trying to be achieved. Whereas here on the forums We have experts that know the context and what is trying to be achieved.

Today i got some disappointing news in which my friend believes is limitations of the software not outputting a Digital signal but rather analog signal. Here are the points he made:

• Software only appears to produce analog RGB output, Suspected that a Card capable of Digital RGB would make the CGA option show up and switch the signal from analog to digital.
• The Jungle IC Input appears to be locked at Digital (Has no way of knowing if it will take analog) Though if it did it would require a software change that is not in the service menu custom reprogramming of the EEPROM
• Circuit interface works fine with a true CGA (TTL) Signal, though does not believe analog signal was ever considered as there is no decoupling capacitor or shunt resistor in the RGB feed from the CPU to Jungle, Just a Single Voltage dropping Resistor inline.
• Believes the only way to do it would be to send a true CGA signal or interface directly to the neck board (Which he does not recommend)

I'm not sure in particular why he keeps bringing up CGA? I have photos of messing with the board and briefly getting the signal to show up so I know the Software does have the capability of moving the Image to the TV but his response to that was as Follows:

When i was touching the board I was passing the 5V (From turn on circuit) to the signal pins effectively pulling up the signal to close to the TTL Levels CGA used.

He stated he could add resistors to do that in the circuit but he sees 2 potential issues:
- I could potentially lose a lot of Contrast
- He also is worried about running injected voltage back through the video card may cause damage.
(He could decouple with capacitors, but stated that might but us back where we started)

The last bit of advise was not to confuse the signal itself with the resolution. CGA is a TTL level signal meaning the 3 colors only have two modes (on and off) The CGA color pallet can only produce 16 colors which is fine for a TV's OSD. The interface injects the signal from the computer into the jungle at the same spot the CPU injects the OSD.

So at this point I'm not sure what to do, would it be helpful to scan the TV's Schematics I have?
Does CRT Emudriver have the ability to push out a digital Signal opposed to an Analog Signal?
Is he right in his assumption that injecting the 5V would cause issues with the contrast and potentially ruin the Video Card?

I really appreciate any time or assistance

[Zebidee]

@Zebidee or @buttersoft

I find myself in between a rock and a hard place, as I sit as the middleman passing information between them with my knowledge painfully lacking.  I have a friend who knows electronics and can do what's asked, but may not necessarily understand the context of what's being asked or what's trying to be achieved. Whereas here on the forums We have experts that know the context and what is trying to be achieved.

Today i got some disappointing news in which my friend believes is limitations of the software not outputting a Digital signal but rather analog signal. Here are the points he made:

• Software only appears to produce analog RGB output, Suspected that a Card capable of Digital RGB would make the CGA option show up and switch the signal from analog to digital.
• The Jungle IC Input appears to be locked at Digital (Has no way of knowing if it will take analog) Though if it did it would require a software change that is not in the service menu custom reprogramming of the EEPROM
• Circuit interface works fine with a true CGA (TTL) Signal, though does not believe analog signal was ever considered as there is no decoupling capacitor or shunt resistor in the RGB feed from the CPU to Jungle, Just a Single Voltage dropping Resistor inline.
• Believes the only way to do it would be to send a true CGA signal or interface directly to the neck board (Which he does not recommend)

I'm not sure in particular why he keeps bringing up CGA?

Your friend is confused. CGA is an old computer graphics/display output standard that allows 4-bit color (16 colours). For convenience, it is designed to be compatible with domestic CRT TVs @ 15.7khz. This is why old games/software have limited colours and chunky resolutions.

Some people think that CGA = 15.7khz display, but this is simply not true.

Colour CRT TVs themselves are analogue and not limited by CGA, and can display essentially infinite colours, within practical limitations. This is why we could enjoy movies on them, with all kinds of shades and colours, back in the day. We can display higher resolutions than CGA on a CRT TV. CGA defines what some (old) computers can output, not what the CRT TVs can do.

So, the whole CGA and "digital RGB" discussion misses the point and is just distracting. The CRT TV definitely 100% takes an analog RGB signal.

The computer's video card takes the digital video information it creates, and converts that into analogue space using a dedicated onboard DAC (Digital Analog Converter) chip. Computer have done this since the dinosaurs. It is only more modern video cards and GPUs that have dispensed with DACs and output digital-only formats (like HDMI). This is why, for CRT_emulator and similar software, we need to use older video cards with analogue outputs like VGA. That is the whole point.

The sync itself is a TTL-level logic signal, though it might be thought of as both digital and analogue. On an oscilloscope it appears a squared wave, essentially either on or off.

I have photos of messing with the board and briefly getting the signal to show up so I know the Software does have the capability of moving the Image to the TV but his response to that was as Follows:

When i was touching the board I was passing the 5V (From turn on circuit) to the signal pins effectively pulling up the signal to close to the TTL Levels CGA used.

He stated he could add resistors to do that in the circuit but he sees 2 potential issues:
- I could potentially lose a lot of Contrast
- He also is worried about running injected voltage back through the video card may cause damage.
(He could decouple with capacitors, but stated that might but us back where we started)

Move the in series capacitors on the RGB signal inputs. They should be on the other side of those resistors, and as close to the IC as practically possible (distance matters).

The RGB signal inputs Need 75R termination (resistor to ground) for the RGB signals.

The sync input needs a resistor in series, as the video card output is too high (around 3.5-5.0vpp), and the TV industry standard expects 0.286vpp. If you assume VGA sync peaks at 5v (probably a bit lower), and there is 75R termination at the TV end, then a 1K resistor gives you exactly 0.349v (close enough).

Note that sync has *nothing* whatsoever to do with contrast or image brightness. It carries no picture information. It simply tells the TV when to draw new lines and when to start the next screen refresh.

I don't understand why he's worried about "running injected voltage back through the video card". There is no voltage "injected" to the card anywhere, even with the alternative sync circuits suggested. The TV and video card would only share a video ground connection, which is standard/normal.

You would probably want to de-couple the H&V sync inputs, to the custom composite sync circuit, with small ceramic capacitors that are not on the schematics I linked (I'd suggest 0.1uF/104 or 1uF/105 values). This de-coupling is more about making sure the composite sync circuit works properly than about protecting the video card from "injected voltage".

Try putting a pot on the 5v blanking signal so you can "tune it in", then replace the pot with a normal resistor. 5v may work for some TVs and not others. True blanking voltage required may be more like 2-3v, every model TV can be different. Schematic might help you to narrow it down.

The last bit of advise was not to confuse the signal itself with the resolution. CGA is a TTL level signal meaning the 3 colors only have two modes (on and off) The CGA color pallet can only produce 16 colors which is fine for a TV's OSD.

This is irrelevant, The TV is not limited to CGA pallet.

The interface injects the signal from the computer into the jungle at the same spot the CPU injects the OSD.[/i]

This is fundamentally correct. It is an OSD-injection RGB mod.

So at this point I'm not sure what to do, would it be helpful to scan the TV's Schematics I have?

Probably not necessary, though I guess it won't hurt anything. Referring to the schematic could help us determine the correct values for in-series resistors on the RGB signal inputs and correct blanking voltage.

Does CRT Emudriver have the ability to push out a digital Signal opposed to an Analog Signal?

This is irrelevant, forget about it.

Is he right in his assumption that injecting the 5V would cause issues with the contrast and potentially ruin the Video Card?

I honesty do not fully understand what he wants to do here. There is no need to "pull up" the RGB or sync. Don't do it.

I really appreciate any time or assistance

No worries.

I have more to say, but am going to finish this post as it is long enough already. Next, I'd like to move on and introduce you to the OSD RGB mux method developed by Mark Ozlad and Syntax (with help from others) from the Shmups forum.

[abstract3000]

Thank you so much for you Response. I will try to make more sense of this in the meantime He sent me  link to how he re did the board and has been looking here https://crtdatabase.com/modding/rgb-via-mux, and it appears we are looking for the CGA Preset is the TV....

I really appreciate the quick response

[Zebidee]

How about you upload that schematic you have? I can see if it is the same as what I've got.

EDIT: or you could just tell me if it is the same as this one
https://www.manualslib.com/download/780770/Sharp-27r-S50.html

[abstract3000]

Sorry there is a Fold in Page A/B, If the fold lands on info you need I can get the info for you

[Zebidee]

Thank you so much for you Response. I will try to make more sense of this in the meantime He sent me  link to how he re did the board and has been looking here https://crtdatabase.com/modding/rgb-via-mux, and it appears we are looking for the CGA Preset is the TV....

I really appreciate the quick response

OK, yes that is basically the same approach I suggest. That site you linked doesn't seem to acknowledge that different TVs are... different.

I've attached that popular RGB OSD MUX diagram. However, you will need to change some resistor values.

You can work this out by looking up the schematic and plugging some values into this OSD mux RGB calculator spreadsheet. The spreadsheet linked is read only, you need to copy it then plug in values on your own copy.

The schematic I have says that your OSD RGB inline resistors are 6.8k, so over-write 5600 with 6800.
EDIT: the schematic you just uploaded seems to have the same values, 6.8K

There are no diodes on the OSD RGB inputs, so we'll over-write 0.7 with 0.0

We WILL add 75R termination resistors, as marked in the diagram, so we can leave the 75 there.

We want the output voltage to be 0.7 or over. If leave the default at 1k (1000) for the Ext RGB inline resistor, we get 0.68v. Close. If we bump it up to the next standard value of 1.2k (1200) then it will be 0.78, a little high. So, choose 1K or 1.2K for the ext RGB inline resistors.

The OSD blanking signal has a 6.8K resistor on it. The spreadsheet suggests we use 3.75K to the 5v blanking, to achieve 1.8v. It also suggests just using the same value resistor, 6.8K. Confusing much? Try a 10K pot (with only two terminals attached), find what value works, then replace with a fixed resistor. Don't just assume that 5v blanking will work.

You'll probably want to put a switch on that blanking voltage, so you can retain input/OSD options. I'm not sure where you'll be getting your 5v, there are a few options. Try starting from the Vcc/power pins, on those main jungle and OSD ICs, and working back towards the voltage regulator(s).

EDIT thanks for the schematic. Different to what I linked, but basic info seems the same.

I see that someone has pencilled in some diodes on the OSD RGB lines. If they are there, then the Ext RGB inline resistors will need to be 1.3K, just like your friend has already done. But I don't see the 75R termination resistors.

[Zebidee]

About that pencil note on your schematic - they wrote "RED | BLUE | GREEN | WHITE". White against BLK.

This made me think about your friend worrying about contrast levels and pull-ups.

Blanc and blanco etc, in many languages, mean white. In most video signals, there is a luma (composite, svideo, component all have it) which is, more or less, brightness and everything else except colour. This luma is carried on the same signal line as the sync. But not so for RGB

In RGB, all that luma data is rolled into the colour signals. The sync is just the sync The blanking is just a switching signal and nothing else, not "white". When the voltage is between X and Y, OSD RGB is switched on.

In terms of pull-ups: most times you'd input external RGB and not use the OSD; but leaving the OSD's RGB lines connected is important for pulling up the voltage. Between the OSD, the jungle IC and RGB inputs, the resistors form a voltage divider matrix, which ideally delivers 0.7vpp to those 104 capacitors and RGB pins.

[abstract3000]

Ok so the TV was altered to the suggestions made above but still no dice here is the current schematic of how it's set up


This is what I got:
I have made the suggested modifications and am even more convinced the issue is the jungle is looking for a TTL video signal.  If I run a CGA TTL signal in we get a perfect picture.  Keeping all the parameter the same and simply changing the signal to analog you get nothing.  Signal is being generated from a Sencore CM2125.

Adding the potentiometer on the blanking line does give me control of the blanking threshold and changing the resistor values I think made the picture crisper but still will not work with an analog signal.[ /i]

As you can see we just put a db15 plug on the TV and running VGA to vga cable from PC directly to TV.

I'm going to try and play with the CRT emudriver software some more tomorrow.

[Zebidee]

OK, that does look about right to me.

Make sure that the PC with CRT_emulator is outputing 15khz signal properly. Try testing it with another 15khz display/TV/monitor, if possible.

If no other display to test on, and if you have access to one, hook up an oscilloscope to check out the sync.

[abstract3000]

Ok so checked the Software and Still no dice, it is in the emulation mode giving out the 15.7, but as mentioned the Sencore CM2125 Machine has the settings 15.8 with the 640x 480 set signal sending the screen. When switching the machine to digital we get a Screen, but when we turn off the digital for analog it disappears. This has us convinced the signal is being locked out due to being Digital RGB, at this link https://crtdatabase.com/modding/rgb-via-mux you can see he states the following criteria is a "Must" for the RGB Mux Method:

• If your jungle does not have RGB inputs you cannot use this method.
• If your jungle has digital RGB inputs you cannot use this method.

we did in fact test the signal on it's way to the Jungle with an oscilloscope and this is what we got:

Digital input gave the following:
.978 (5.28pp)


Analog Gave the following:
.128 (2.3pp)


All throughout the SHUMPS Thread it is mentioned that if the Jungle is Digital RGB it's a no go. So this had us seriously discouraged. Though after reading for a few hours through everything I stumbled upon a post that discussed the Sanyo LA76843N Chip which you linked earlier "IX3354CE" chip is really a "X3354CE" chip which is really an "LA76843N" <- That was quoted from MarkOZLAD.

So the Thread I stumbled upon discussed how Voltage needed to be injected into the RGB Lines for this Chip to get the Signal. This explains in the first attempt of the mod, why when handling that little circuit board I had with both the auto on circuit and the RGB mod, when messing around with it I managed to get an image displayed as I must have been accidently introducing the 5V from the On/Off circuit to the RGB lines. You can see The picture here on the screen:


So It appeas from his workup on Stack Exchange here: https://electronics.stackexchange.com/questions/568045/single-supply-op-amp-non-inverting-level-shifter-for-ntsc-signal-processing-from/568154?noredirect=1#

He uses the THS7315 OP amp and drives it up to 2.5Vpp, though my friend suggests it might get better with 3.5Vpp. Not sure if you have any idea on this work around, or most likely being a one off. The issue is all the people involved in this model of TV MarkOZLAD, rx7turbo233, Syntax, and benyamin39 have not logged into the forums over there for months or in a couple cases years. The main thread has ran stagnent with the tail end just being numerous people asking for help with no response from those that once lead it. I understand the times change and people move on, but it would be great if I could at least get ahold of the Ben guy to see what the final results were.

I tries responding to his thread quoting it "Crossing my fingers" it triggers an Email and he checks, but luckily it appears to be allot of detailed info he left behind that at least we have something to work with.

[Zebidee]

Ok so checked the Software and Still no dice, it is in the emulation mode giving out the 15.7, but as mentioned the Sencore CM2125 Machine has the settings 15.8 with the 640x 480 set signal sending the screen. When switching the machine to digital we get a Screen, but when we turn off the digital for analog it disappears. This has us convinced the signal is being locked out due to being Digital RGB, at this link https://crtdatabase.com/modding/rgb-via-mux you can see he states the following criteria is a "Must" for the RGB Mux Method:

• If your jungle does not have RGB inputs you cannot use this method.
• If your jungle has digital RGB inputs you cannot use this method.

I get this now. The TV can show analog fine, but the digital OSD RGB inputs won't read analog.

we did in fact test the signal on it's way to the Jungle with an oscilloscope and this is what we got:
...
Analog Gave the following:
.128 (2.3pp)

I don't understand this, as you say you are measuring sync before it gets to the jungle IC. Are you measuring the analog sync at (or close to) the composite/AV input jack? Analog sync should still have the square waveforms, much like the digital input picture you showed. If there is no sync from the VGA card, might explain some things.

Check the sync both before and after any modifications (resistors etc).

So the Thread I stumbled upon discussed how Voltage needed to be injected into the RGB Lines for this Chip to get the Signal. This explains in the first attempt of the mod, why when handling that little circuit board I had with both the auto on circuit and the RGB mod, when messing around with it I managed to get an image displayed as I must have been accidently introducing the 5V from the On/Off circuit to the RGB lines. You can see The picture here on the screen:


So It appeas from his workup on Stack Exchange here: https://electronics.stackexchange.com/questions/568045/single-supply-op-amp-non-inverting-level-shifter-for-ntsc-signal-processing-from/568154?noredirect=1#

He uses the THS7315 OP amp and drives it up to 2.5Vpp, though my friend suggests it might get better with 3.5Vpp.

The blanking signal might have multiple states? Like, it might be one voltage level for digital, another for analog. When your finger touches the 5v for blanking, it may be pulling the voltage down (like a voltage divider, some of it being grounded through you), triggering analog. It's just a theory, but it is quite common for different blanking voltages to trigger different things. Could be worth putting that pot back on and going through the range while inputting analog.

You could try a video amplifier from Ultimarc. They are relatively cheap, a bit more powerful, and I think they supply a VGA cable with it.

What puzzles me about this is that if this amping idea works, I'd expect to see at least a faint image without it. Maybe there is a threshold.

Not sure if you have any idea on this work around, or most likely being a one off. The issue is all the people involved in this model of TV MarkOZLAD, rx7turbo233, Syntax, and benyamin39 have not logged into the forums over there for months or in a couple cases years. The main thread has ran stagnent with the tail end just being numerous people asking for help with no response from those that once lead it. I understand the times change and people move on, but it would be great if I could at least get ahold of the Ben guy to see what the final results were.

I tries responding to his thread quoting it "Crossing my fingers" it triggers an Email and he checks, but luckily it appears to be allot of detailed info he left behind that at least we have something to work with.

Those guys, especially MarkOzlad and Syntax, would probably know what is possible. They both post on the FB CRT groups. Mark is one of my friends and I've seen him active recently, at least on the Aussie CRT group. I'll PM some details to you so you can contact him.

[abstract3000]

Well, My friend told me had an Idea he wanted to try and I didn't hear back for a week it appears he ordered one of the Video amplifiers from Ultimarc as you suggested Zebidee, and in Positive news the Picture is now on the Screen (but appears to be inverted/ black/grey Scale with White Text) We are not understanding at what point the Video could have become inverted, but my friend wanted to give a shot at building an inverter to see if that fully corrects the issue. So waiting for those results.

Had I known this Sanyo Jungle was such a pain in the Ass I think I would have just spent more time trying to find a 27" CRT on FB marketplace to buy that either had the RGB inputs already or was something like Sony and well known to be capable of modding.

The theory we have with this TV is that the Jungle RGB Inputs are Digital therefore as speculated amongst the community is non moldable, but I believe we are bypassing that by raising the Analog Signal to the Same Voltage as Digital and fooling the chip to take it so to speak, but how good it will turn out at this point is anyone's guess :/

[Zebidee]

More options for you:

"Neckboard" mod

Hacking directly into the jungle's RGB output to the neckboard. You don't necessarily have to do it physically at the neckboard either, you can probably do it right on the main chassis, before (or even at) the neckboard connector.

I've never actually done this myself. I know it is possible though. The main trick is to figure out the voltage levels.

The schematic I have shows RGB out on pins 19,20,21. It shows expected voltage levels for those pins, at 2.3 2.4 2.5 respectively. About 2.5v then. The block diagram (click on the thumbnail above) show RGB Vcc at 9v, so seems it uses that to give the RGB outputs a fair boost to ~2.5v.


     


That ultimarc amp should boost the RGB voltage to approximately same level, so worth a go.

Still need to terminate each RGB input with 75R resistors, and after that a ceramic cap (100nF 104) and a 100R resistor in series.
Like this x3, hijacking the neckboard connector (should be 5 pins, RGB+GND+9v). Alternatively, tap into the base of the 100R resistor already there. If the RGB is too bright, try pots (low value, probably 100R or 200R range sufficient) in series before the 75R terminations.


RGB input------?POT?-------------------CAP 104------100R------neckboard connector
                                           |
                                         75R
                                           |
                                        GND



Input the sync via composite as usual.

Pot on blanking signal

With the existing mod, and if your mate hasn't already done this (not sure if he has?), put a 3-pin pot on the blanking with middle pin to ground, to make a voltage divider. Try the full pot range. Different voltages may trigger different result. That's my "Hail Mary" for the OSD approach. Otherwise I think try hacking the neckboard/jungle output.

Inverted picture

Regarding the "inverted" video, you can easily address that by flipping the yoke coil connector. If you mean upside-down, flip the vertical coil connector. If you mean mirrored, then flip the horizontal connector. Each coil has 2 pins, typically joined as a 4-pin yoke connector. You would need to cut that in the middle, between the pins, to separate the H and V coils. Flipping the coils won't help with correcting the colour though.

[abstract3000]

Thanks for the Info Zebidee, My friend Advised from the get go that hacking directly into the Neck was an option but one he would prefer to leave alone. It appears I spoke too soon in reference to what we thought was an inverted signal.

He got the picture coming through and in Color none the less, apparently the issue was the decoupling Caps, that were never present before, removed those and the Signal passes right through. Though 2 Things are a a bit off (the colors look really good an vibrant) but The screen resolution looks the same as it does on my PC monitor, so 640x480 is not what the TV is liking, so Going to have to find a way to Change the resolution it sends over.

The second thing is what we believe to be the Vertical Sync, there is some waviness of sorts around the screen, but I see in VMMaker adjustments can be made, I did play with it a bit when i was over there today and i saw it did change it, so will have to play with it a bit more.

[Zebidee]

Thanks for the Info Zebidee, My friend Advised from the get go that hacking directly into the Neck was an option but one he would prefer to leave alone. It appears I spoke too soon in reference to what we thought was an inverted signal. He got the picture coming through and in Color none the less, ...

Good news then! I was hopeful that you could do the input via OSD because you said you got a picture briefly, which means it must work somehow.

... apparently the issue was the decoupling Caps, that were never present before, removed those and the Signal passes right through.

Try different values for the decoupling caps, perhaps one or two orders of magnitude lower or higher.  The theory is that different capacitor/resistor combos resist different frequencies. High-pass or low-pass filters. I don't really want to go into theory I barely understand myself, but this is possibly what is blocking the signal.

Capacitors in parallel add total capacitance, so when testing it is easier to start small and go big. You just solder the higher capacitor onto the legs of the earlier one. If you used 104 (100nF) caps before, remove them and start with some 102 (1nF) or 103 (10nF) first. Then try some 105 (1uF) caps, even 10uF if you dare. Because 1.011uF is about the same as 1uF, you don't have to remove the smaller caps for this kind of testing.

Though 2 Things are a a bit off (the colors look really good an vibrant) but The screen resolution looks the same as it does on my PC monitor, so 640x480 is not what the TV is liking, so Going to have to find a way to Change the resolution it sends over.

Not sure I understand what you mean there. Pics? Even with CRT_emulator, there remains a "native" 640x480 that is a VGA resolution hardwired in by Windows (thus "native"). Go into Arcade_OSD and change your desktop to the "custom" 640x480 interlaced res. Or something else

I'm mostly using 720x480i@60hz on my TVs desktops now - it is essentially NTSC standard. A tiny bit of letterboxing, but despite that the pic looks a lot crisper (an extra 80 pixels on each line) and seems easier to fit most of the desktop on screen, with little overscan. TV seems designed for it! Also saves me that native/custom confusion. I just add it to my user_modes list.

The second thing is what we believe to be the Vertical Sync, there is some waviness of sorts around the screen, but I see in VMMaker adjustments can be made, I did play with it a bit when i was over there today and i saw it did change it, so will have to play with it a bit more.

There are all kinds of possible reasons for this. You sorted out that resistor on the sync input yeah? Maybe your mate could hook up the scope again and have a look, it looked wrong before (more like static). You need to zoom in to like 200us or less to really see it properly, because an entire line of sync is only ~64us long.

[abstract3000]

Try different values for the decoupling caps, perhaps one or two orders of magnitude lower or higher.  The theory is that different capacitor/resistor combos resist different frequencies. High-pass or low-pass filters. I don't really want to go into theory I barely understand myself, but this is possibly what is blocking the signal.

I discussed this with My friend he stated he did tried a range with the caps and got nothing, hence removing them he realized it most likely wasn't going to go with them.

Not sure I understand what you mean there. Pics? Even with CRT_emulator, there remains a "native" 640x480 that is a VGA resolution hardwired in by Windows (thus "native"). Go into Arcade_OSD and change your desktop to the "custom" 640x480 interlaced res. Or something else

I have gotten into the Arcade_OSD Swapped the Resolutions then put into the Emulation mode with multiple resolutions to no avail, I even tried changing the resolutions from the desktop while it was being emulated to the CRT with no Change.

See the Pic below, it's almost as if the Screen Area it's filling is larger than the actual "Viewing" area


I know this most likely has nothing to do with it, as they are separate but the LCD Monitor I'm using shows the Same damn thing when I put into Emulation mode


So the other issue I can't capture in a video or a picture is the "Flashing" maybe what I'm seeing is a Refresh issue? It occurs around Windows Boxes, menus etc, and the text in the Windows Explorer is pretty garbled, but when you put a Picture or a Video up, you don't get this quick "flashing" (excuse me I'm sure this has a proper term, but i don't know a better way to describe it)

There are all kinds of possible reasons for this. You sorted out that resistor on the sync input yeah? Maybe your mate could hook up the scope again and have a look, it looked wrong before (more like static). You need to zoom in to like 200us or less to really see it properly, because an entire line of sync is only ~64us long.

At this point I am on my own I have the TV back and he stated he did everything he could do with it. I appreciate all his efforts, but I know it was taking up space in his shop he needed back and he really went through a lot to get it finished.

He did however leave the micro pot on the board for me to fine tune the blanking signal in the event i want to use the Svideo Option instead, but in his belief he really thinks there is something to do with the Vertical Synch and hopefully the Software/Drivers I'm using Can adjust that. I think I wil try setting up MAME on the System now and loading a Game to see how it even looks for that matter, but was hoping I could do something to get the screen adjusted so you could see the entire Windows Menu Bar at the bottom

[Zebidee]

OK, looks like you've got it working anyway. It's hard to take good screenshots, but your picture looks pretty clear and you seem to have all the colours.

I have gotten into the Arcade_OSD Swapped the Resolutions then put into the Emulation mode with multiple resolutions to no avail, I even tried changing the resolutions from the desktop while it was being emulated to the CRT with no Change.

I don't understand what "emulation mode" is? You mean EDID emulation? I usually just leave that alone. Despite the name. it has nothing to do with actually using game emulators. It concerns fooling the computer into regarding your TV as a proper monitor. I'm not really an expert with CRT_emulator, but think I recall someone saying that whenever you click that, you should re-generate and re-install the video modes.

See the Pic below, it's almost as if the Screen Area it's filling is larger than the actual "Viewing" area

The pics you show actually look fairly normal. Overscan (the desktop hidden behind screen edges), especially in 640x480i, is typical with TVs.

Later, you can trim the frontporch/backporch of the CRT_emulator modes to minimise overscan, but it will probably never be entirely gone. I get less overscan with desktop set to 720x480i. You can also have a look around in the TV service mode geometry adjustments, but be careful as sometimes it is possible to set values for which TV cannot display an image! Then you'd be stuck.

So the other issue I can't capture in a video or a picture is the "Flashing" maybe what I'm seeing is a Refresh issue? It occurs around Windows Boxes, menus etc, and the text in the Windows Explorer is pretty garbled, but when you put a Picture or a Video up, you don't get this quick "flashing" (excuse me I'm sure this has a proper term, but i don't know a better way to describe it)

Do you mean that the picture does not stay on screen, comes and goes ("flashes") fairly quickly? Maybe rolling picture? But stabilises once you have a window open? This is a strong indication that there is no vertical sync coming through. Possibly no sync at all. This is because the TV, in a desperate move, attempts to guess where the sync is by identifying gaps in TV video signal input. The video signal is more distinct when you have windows on the desktop, making it easier for the TV to guess at beginning and end. You might lose sync for a moment if you try moving windows around on the desktop.

How did you end up doing the sync? You still using the Ultimarc video amp? That outputs composite sync already. Take that, run it through a resistor (depends on sync voltage, but try from 470R up to 1K) into the TV's composite/AV input.

Alternatively, your "flashing" around window edges might simply be that you are noticing interlacing in modes like 640x480i. Interlaced modes refresh lines at half frequency, so there is enough time to draw two lines "interlaced" with each other, in the same time it takes to draw one line in progressive modes like 320x240p. Total screen refresh rate remains the same, twice the lines but each is drawn half as often. The slower line refresh rate is much more obvious around straight lines.  Hard to notice with non-linear images, and you probably won't be able to notice it at all with video, which is why it works for normal TV.

[abstract3000]

but your picture looks pretty clear and you seem to have all the colours.

Yeah the picture is clear, yet not so sure about all the colors the Whites are "Really Really Bright" I also opened this Jpeg on the Monitor


And this is What I got

Do you mean that the picture does not stay on screen, comes and goes ("flashes") fairly quickly? Maybe rolling picture? But stabilises once you have a window open? This is a strong indication that there is no vertical sync coming through. Possibly no sync at all. This is because the TV, in a desperate move, attempts to guess where the sync is by identifying gaps in TV video signal input. The video signal is more distinct when you have windows on the desktop, making it easier for the TV to guess at beginning and end. You might lose sync for a moment if you try moving windows around on the desktop.

Ok so think of the Windows in the Explorer, and the black lines that make up the border or the windows or the Menus that pop up, now think of a fluorescent light bulb on its way out, how it starts doing that rapid flashing of light (dark bright, dark bright, in rapid recession) and around the desktop Icons themselves the screen is jittery/wavy so your stating refreshing is redrawing itself rapidly but not fast enough for my eyes not to see it I assume that's probably what I'm seeing? Though open a Normal Picture or play a video you don't see any of that (just the Windows components of the operating System)

How did you end up doing the sync? You still using the Ultimarc video amp? That outputs composite sync already. Take that, run it through a resistor (depends on sync voltage, but try from 470R up to 1K) into the TV's composite/AV input.

The synch was just piped on pin 13 through the DB15 last I knew to composite, yes the Ultimarc Video Amp is still in use but not enough power by itself so it is also connected to the PC for power as well.  If I unplug that from the PC power supply I get No screen, the instant i plug it In I have screen.

I tried the 720x480 I had available to me in the Arcade_OSD and the Icons dropped even further down in the overscan. The last strange issue I took a video of is when i grab a window and drag it around, when it gets like to the sides or most noticeably the bottom corner is bends the picture as if it's pushing what's there out of the way to make room (Like the clock in the bottom right corner) The clock doesn't disappear but rather bends/distorts slightly like it's making room for the incoming window and when you move it away it bounces right back to normal.

[Zebidee]

One last time: put the sync through a resistor 

Without a video, what you describe sounds like you are just noticing interlacing.

The last strange issue I took a video of is when i grab a window and drag it around, when it gets like to the sides or most noticeably the bottom corner is bends the picture as if it's pushing what's there out of the way to make room (Like the clock in the bottom right corner) The clock doesn't disappear but rather bends/distorts slightly like it's making room for the incoming window and when you move it away it bounces right back to normal.

This is "blooming", a very common thing with CRTs. As the image gets brighter, more voltage is being pumped at the CRT phosphors and the picture gets a bit bigger. Better CRTs do it less, but they all do it. Many games actually take advantage of it. For example, try loading up Golden Axe and let it run in demo mode - it takes advantage of blooming when the title comes up on screen.

From that first pic of the test colour field, looks like you may need to adjust the flyback, brightness and RGB cutoffs in the service menu. While you are there, you might find some geometry controls for V and H-size or similar.

You probably also want to play with the CRT_emulator monitor presets, and/or adjust modelines via arcadeOSD, to minimise overscan.

In general though, well done.

[abstract3000]

One last time: put the sync through a resistor

I sincerely apologize, I meant to comment on this with my last post but dropped the ball. As mentioned I am alone on this project at this point forward so I will need to source those resistors (470R up to 1K) and most likely a small breadboard, there's no Radio Shacks around so It will be a bit of a drive for me to get those. So that might be a bit before I can give that a shot.

In the meantime I am setting up MAME, the last set I had procured and finely tuned was .206 and I cannot find a version of GroovyMame that far back even through the archives, So transferring the base set now of .260 and when I get that all set up with CRT_Emudriver I want to give it a shot and see what I get on the Screen to give me an Idea of how much time and effort to keep dispensing on this, and fine tuning it out so I have some decisions to make I suppose.

I assume the MAME setup I should have done by tomorrow night, and will probably drag everything to the monitor out in the garage to screw around with it on Thursday some more and have a better Idea of where I really stand with the picture and the purpose.

There are 2 knobs on the back of the Flyback, I have considered looking into giving those some fine adjustments, and as in the Service menu you mean the typical menu you change brightness and Contrast levels? I was going to give that a Shot as well.

I will update you a bit more in a couple days where I'm at and will start looking for the Resistors, will just trace out pin 13, cut it between the small board and the TV Motherboard, plug both ends into a bread board and take turns swapping out the resistors to see if there is any change

[Zebidee]

One last time: put the sync through a resistor

I sincerely apologize, I meant to comment on this with my last post but dropped the ball. As mentioned I am alone on this project at this point forward so I will need to source those resistors (470R up to 1K) and most likely a small breadboard, there's no Radio Shacks around so It will be a bit of a drive for me to get those. So that might be a bit before I can give that a shot.
...
I will update you a bit more in a couple days where I'm at and will start looking for the Resistors, will just trace out pin 13, cut it between the small board and the TV Motherboard, plug both ends into a bread board and take turns swapping out the resistors to see if there is any change

You can buy resistor "kits" online, which have a bunch of different values, for a few dollars. 1/4W rating is plenty for most DIY low-voltage DC stuff that we do. This is really just for your TV's protection from over-voltage and ensuring there are no other issues going on -  but it seems to be working as-is for now.

While you are online, grab some heatshrink tubing. Also, make sure your soldering iron is ready to go   You should not need a breadboard for this - just cut the wire, splice the resistor in. When happy, slide some heat-shrink over the join.

In the meantime I am setting up MAME, the last set I had procured and finely tuned was .206 and I cannot find a version of GroovyMame that far back even through the archives, So transferring the base set now of .260 and when I get that all set up with CRT_Emudriver I want to give it a shot and see what I get on the Screen to give me an Idea of how much time and effort to keep dispensing on this, and fine tuning it out so I have some decisions to make I suppose.

I assume the MAME setup I should have done by tomorrow night, and will probably drag everything to the monitor out in the garage to screw around with it on Thursday some more and have a better Idea of where I really stand with the picture and the purpose.

You can download Groovymame 0.206 here

There are 2 knobs on the back of the Flyback, I have considered looking into giving those some fine adjustments, and as in the Service menu you mean the typical menu you change brightness and Contrast levels? I was going to give that a Shot as well.

The bottom knob is the screen voltage. Top knob is focus. Set brightness and contrast in neutral/middle setting, and put a dark screen or game on display (Galaga works OK). Now adjust screen voltage up a little bit, then down until the flyback retrace lines disappear completely. Flyback retrace lines are the faint and slightly diagonal lines you'll see, especially near the top, when screen voltage is high. Once you have the screen voltage right, adjust the focus until everything looks as sharp as possible.

Adjusting flyback is not the same as brightness/contrast, nor is it a substitute. It is more about getting the base level right, and you don't want to be adjusting flyback screen voltage every day. Your brightness/contrast are there for day-to-day fine-tuning.

When I was talking about RGB cutoffs, they are not the same as brightness/contrast either. Cutoffs are the minimum level at which the colours will be displayed. You might see them in the service menu as "RC", "GC" or "BC", or maybe something else. You will not see them in normal TV menu, they are not the same as brightness/contrast. Your display seems to be bright enough, but lacks colours at low brightness levels. That's why I ask about the RGB cutoffs.

[abstract3000]

Thank you so much for giving me the link to that .206 Version!

So as for the Sharp 27R-S100 Set that project I suppose is officially dead. :/ After grabbing the photos for you the other day and shutting everything down that was the last time That Set ever turned on. When I came out the next day to try MAME, the Set would no longer even power up, I checked all the solder points, tops of Caps, fuse etc. and have no idea. I txt'd my friend to ask him what his thoughts were and no Response, he is at the end of his rope with the TV and rightfully so.

I went out and purchased a Panasonic CT-27D11E, which has both S-Video and Component YPbPr Inputs, I bought a $15 S-Video Video card to fall back on. Though I am no longer interested in this RGB Mux mod stuff, It sounds awesome but between paying for the mods done on the last TV and buying the New TV I'm out $525 and nothing to show for it (back to square 1) Where i could have just simply purchased a $15 S-Video GPU, and had it running like it used to. So a bit bitter about the entire thing honestly and feeling defeated, just want a working monitor, and finding the Panasonic set was a diamond in the rough and required a bit of a drive. The other option was another of the Same set and an 8 hour round trip.

I do however greatly appreciate all the time and effort everyone has lent in helping me on this tragic journey

It seems though that you can use CRT_Emudriver with a transcoder to then filter to YPbPr and get great results, though I think you again need a transcoder. There is this one on eBay that states it handles 240p - 1080i
https://www.ebay.com/itm/174166352619

If thats the case, then I will just get that and call it a day, otherwise I might just plug S-Video back in to finally put a close on the project.

[Zebidee]

Thank you so much for giving me the link to that .206 Version!

No worries

So as for the Sharp 27R-S100 Set that project I suppose is officially dead. :/

I went out and purchased a Panasonic CT-27D11E, which has both S-Video and Component YPbPr Inputs,...
It seems though that you can use CRT_Emudriver with a transcoder to then filter to YPbPr and get great results, though I think you again need a transcoder.

You can get fantastic YPbPr results with a transcoder, which is exactly what my GreenAntz VGA->component transcoders do. Just now, I've been running two cabs side-by-side, one with a component-modded generic 21" TV + GreenAntz and the other with an RGB/SCART Panasonic 28" TV. The CRT_emulator setup in both is identical in each, no special setup required. In most cases I honestly can't tell the difference between YPbPr and RGB.

Sorry for hoisting my own flag, I'm between revisions on GreenAntz ATM so I couldn't sell you one right now anyway. Hopefully I'll have some to go before Christmas. However, if you can get one of JAM's quite decent wakabavideo ones, grab it because most of the time he's sold out too.

[abstract3000]

You can get fantastic YPbPr results with a transcoder, which is exactly what my GreenAntz VGA->component transcoders do. Just now, I've been running two cabs side-by-side, one with a component-modded generic 21" TV + GreenAntz and the other with an RGB/SCART Panasonic 28" TV. The CRT_emulator setup in both is identical in each, no special setup required. In most cases I honestly can't tell the difference between YPbPr and RGB.

After doing allot of reading over the last couple months on this, I had kind of gotten the idea that had i not had the S-Video but rather YPbPr Component, I would have been allot better off to begin with and never would have went through all this. I saw several screen shots of people using Transcoders to Component, and honestly I don't care of RGB is somehow better I don't even think I would have been able to figure it out and see up that closely. I never had an issue with the S-Video to begin with but these are the tolerance differences we are looking at here:

SVIDEO VS RGB

I Could go confront my friend on the dead CRT, but i feel even if he did manage to get it resurrected, we would be back to fine tuning that thing and hoping we could work through most of the obvious issues, always wondering in the back of my head when would it go dead. I know he has done allot and is tired of working on it, just as tired as I am hauling it back and forth and discussing it with him so I let the sleeping dog rest and figured learn from my mistake. It's almost meant to be with this new CT-27D11E, I Set my search radius a few hundred miles, I figured I'm on Vacation and have time to drive. Only 1 CRT I could find that matched the specifications 27", Curved Screen, YPbPr inputs. Crazy how scarce these are getting, but the guy was willing to negotiate and not as far as I expected.

So I went ahead and bought 2 Transcoders I bought this Cheap Chinese one off of Amazon because it will arrive tomorrow and I can continue to play with it while on vacation:


I read several reddit posts, a write up on the Shmups board on it, and watched a Video Review looking at the comments sections with several confirmations that running from PC with CRT Emudriver to Component worked great. I also spent the $80 (cringe) on wakabavideo's Transcoder but that wont get here till later next month i suspect coming all the way over from NZ. I saw it up for sale yesterday with 5 remaining for 530 originally available, when I logged in this morning 1 left. Figured it must be a good one, and will most likely last allot longer than the chinese one, but the amazon special will get me by to get everything setup.

Though once again I really appreciate all the help from you over the last couple months on the Sharp TV I will post some pictures when i get everything setup.

[Zebidee]

Don't give up on the Sharp TV, though may be wise to take a break from it. Hopefully it is a simple problem.

SVideo quality is quite OK, but for your mame setup will still look mediocre. The bigger issue is the video card will be outputting in a squished & interlaced video mode, either 640x480i or NTSC 60hz. You won't get any benefits from running games in original pixel-perfect video modes.

You'll have noticed the SCART input on the Chinese units - this is because they don't do anything to combine the separate H+V sync to composite. You have to do that yourself.

Those cheap Chinese ones ripped off an early GreenAntz design I published 5 years ago, on another forum. A mate published his version on Github. Chinese ones didn't exist until about 9-12 months afterwards. Some version of my design and now you buy them on Amazon & Aliexpress. Since publishing, I (and my mate) solved the sync and various other improvements. So, that is why the cheap Chinese ones don't do the sync. I also why, even though I believe in principles of open source sharing cooperation yada yada, I don't publish designs anymore.

With the China ones, you'll need to make or hack (or buy) a VGA-SCART cable. You'll also have to combine the sync somehow. Simplest way is to twist H+V together and run that in to SCART pin 20 through a 1K resistor. This is not perfect but probably sufficient for most TVs, though some may have trouble locking on and many will show artifacts, like a zig-zag at top of screen.

[EDIT] You can get decent composite sync via the CRT_emulator/VMMaker option. You will still need the resistor.

You don't have to worry about all that with a GreenAntz unit - just setup CRT_emulator and plug it in. Comes supplied with 4 standard PCB offset legs, making it super-easy to install in cabs (just screw it down!).

[abstract3000]

Well, the SHARP TV is up and running again, messed with it today and got it going. The picture is back up, tested with Games and my suspicions were right, the interlacing issue goes away and the games seem to display just fine. Though offset a bit which stated could be fixed with adjusting the horizontal and vertical porch settings though this brings up 2 new things today, I need to think about.
 
(though before that, yes I did order the resistors, though when I spend some time with the multimeter tomorrow on my friends mod I have a feeling I'm going to find a resistor on the synch as he is pretty wise individual, but If not I will add it.)

1st issue. I am convinced something is up with the EDID Emulation when sending the signal through, what you are calling the offset is identical on the monitor and the TV, what has me convinced of this is with the new Chinese adapter I got today I hooked that up to the Panasonic ran the signal through and it displays just fine but the image is offset identical on that one as to the monitor and the other CRT and even more to a degree. Why do I believe this offset is an issue? Well in the first images I showed early on getting the signal through the TV displayed the entire image of the desktop with the Task bar fully visible. So I'm guess with all my playing around with Arcade OSD and CRT_Emulator I messed something up. I get that the EDID emulation isn't the "important" part but you don't get a signal unless its turned on.

2nd issue is with colors, maybe you might have an idea what it means, I discovered today with the SHARP that the Green shows sometimes for some things but is missing in allot of other things and I almost believe if this issue is fixed that would be the end of most everything

Here is an example of Paperboy on the SHARP CRT


Now here's an image of Paperboy on the Panasonic CRT


In your expert opinion what does that mean? Or What would be the root cause of that?
You mentioned to go checkout the RGB cuttoffs, I got the service manual and studied it a bit, and found out how to get into the service menu. Here in the service menu I have these particular options:



I highlighted the most obvious, but which one of those would be the cutoffs?


oh and here is an image from the Panasonic connected to the cheap Chinese adapter, this is out of the box no adjustments, as well Groovymame has not been configured with CRT_Emudriver either, I think the colors look really good actually.

[Zebidee]

1st issue. I am convinced something is up with the EDID Emulation when sending the signal through, what you are calling the offset is identical on the monitor and the TV, what has me convinced of this is with the new Chinese adapter I got today I hooked that up to the Panasonic ran the signal through and it displays just fine but the image is offset identical on that one as to the monitor and the other CRT and even more to a degree. Why do I believe this offset is an issue? Well in the first images I showed early on getting the signal through the TV displayed the entire image of the desktop with the Task bar fully visible. So I'm guess with all my playing around with Arcade OSD and CRT_Emulator I messed something up. I get that the EDID emulation isn't the "important" part but you don't get a signal unless its turned on.

Errr...., "offset" is your term, the only time I've used the word here was regarding PCB offset feet which are used to physically screw down a GreenAntz unit.

As you've discovered, EDID emulation either works or it doesn't. It has nothing to do with your overscan issues. If it ain't broke leave it alone. I recall someone saying somewhere that every time you click EDID emulation on/off, you should re-generate and re-install the video modes. So keep that in mind.

2nd issue is with colors, maybe you might have an idea what it means, I discovered today with the SHARP that the Green shows sometimes for some things but is missing in allot of other things and I almost believe if this issue is fixed that would be the end of most everything

In your expert opinion what does that mean? Or What would be the root cause of that?

Yeah, your Sharp TV definitely lacks green, though not completely. Seems to be absent entirely at lower levels. However it seems to be present if the signal is strong enough. Which is why I think about RGB (green) cutoffs (not offsets, presets or porches...).

Does the Sharp TV lack green with other inputs? If so, maybe there is an issue with the green drive circuit or the cathode in the tube itself.

Another possibility is that with S-video (& YPbPr), the Y signal carries both sync and luma. Luma mostly concerns brightness, but is also important for determining green in particular. If you are putting sync in via composite/AV input, and there is no resistor on it, then it could possibly be swamping the green.

To explain... sync signal is simply "ON" most of the time. Sync pulse is triggered by low-active state, a lack of voltage. Sync is carried on the Y (luma), which also includes picture information. By running the sync in from VGA at 5v, you're essentially blasting luma at more than max into the TV, through an AV input designed for 1v max. Of that, the actual sync part of that signal is only meant to be 0.3v max.

This is why I go on about the resistor on sync. This is really the bare minimum.

(If it was me, I'd also use a Schottky diode (IN58XX, reverse biased, cathode to signal, anode to GND) to CLAMP the sync to GND. A second schottky diode, in the opposite to orientation (forward biased), would then limit the sync to approximately 0.3v max. This is CLAMPING, it just keeps sync within normal range and makes it easier to for the TV to work out which is what. I've harped on about this more than I've wanted to. Please show me more pics!)

Anyways, the jungle blanks AV input (except the sync) when the OSD is active (that's why they call it a "blanking" signal), so I'm entertaining a hypothesis that the jungle is blanking a field of green, and that somehow means you have little green for your RGB OSD mod. Easiest way to test this theory would be to disconnect the blanking voltage and see what kind of image you get - if you see a bright screen, either white or greenish, then that could be the problem.

Another cause could include the Ultimarc amp (if it isn't boosting green as much), but this seems unlikely.

You mentioned to go checkout the RGB cuttoffs, I got the service manual and studied it a bit, and found out how to get into the service menu. Here in the service menu I have these particular options:



I highlighted the most obvious, but which one of those would be the cutoffs?

You'll have to experiment for yourself. Every TV is different, and each manufacturer seems to use different terms, so I can't be certain. All I could really do is make educated guesses.

XXX_BIAS are likely equivalent to "gain", concerning colour brightness. XXX_DRIVE might be colour intensity, but it also might concern the cutoffs (minimums) I mentioned. Sometimes I see the cutoffs listed as "RC", "BC", "GC".

You should also look out at settings like "YC", which probably concerns a balance between Y (luma, brightness & sync) and C (chroma, colour).

H_BLK_R and H_BLK_L may be for tweaking the horizontal position.

BS_START and BS_GAIN sound like they could be worth adjusting, but I'm not sure what they might be for.

I wonder what R/B_ANGLE is about, whether it concerns the colour mix.

Leave settings like TINT, CONTRAST, COLOR, BRIGHTNESS at neutral settings, at least until you've bedded down your setup a bit.

SHARPNESS should be set to zero (00) or a neutral setting. Go with 00. It is for making crap TV or VCR signals look less crap - doesn't do anything useful for RGB or component inputs.

You may have other pages of service mode adjustments - my China TV has 20 pages! Most are not accessible without entering more service mode codes.

[abstract3000]

ok so this is going  to be a headscratcher, i have spent a bit more time with the TV and this is the info I have gathered

Let's start off with the Resistor on Synch. It is there and always has been, i looked at the schematic posted earlier and it is on there, I used my multimeter verified this and the fact it is a 1K resistor.
I have reposted the Schematic below, this is the current setup except for the decoupling Caps that were removed.



Here is a Picture of the modification going to the TV


This is the Ultimarc Board connecting to a project board, the more important thing to note is that there is a trim pot on that board connected to the blanking, that will make more sense as I continue on with my observations.

So i found a Panasonic 3DO laying around that had an S-Video Output, I connected it to the TV swapped the Input and everything looks great colors wise, nothing seems to be out of place. I managed to snap this photo that depicted several shades of green all appearing correctly.


Now lets move back to the RGB Mod and discuss the Blanking.
You See how the Picture looks fine? Well I can't just switch from the RGB to S-Video and have a picture with great colors, I have to adjust that trim pot all the way to the other side to get S-Video to show up. Now lets Say S-Video is to the Right, and RGB is to the left (don't thing about that too much i might have it backwards) Anyways in the middle sits is a black screen and distorted graphics and what I believe is called the OSD (On screen display?) It's the text that appears on the screen when you change a channel, or hit the menu button. (Don't shoot me if I'm wrong) Well there is a sweet spot you can get to where you can see that text just barely visible unless over light colors it will be black.

This is what Paperboy looks like when the Blanking has been adjusted to where I will be able to see the menu


Now here is a photo of the menu pulled up and here is the funny thing, look at the letters themselves; they are the accurate colors of what's supposed to be displayed below them on the Screen?!?!?!


So that's where I'm at, I also tried to get into the service menu but at this point i feel it's a lost cause, So the only way I can get into the service menu is by adjusting the blanking as seen in the previous photos, then putting into regular channel mode (no RGB or SVIDEO) the menu refuses to come up in either of those 2 inputs. Then when I get it up it looks like this:


I mean I can really struggle through changing a value if needed, but when I change the value I have absolutely nothing but static to see what impact said change even made so I left it alone.

[Zebidee]

I'm guessing that there is a problem with the blanking voltage. When you use the OSD it overlays the image, showing correct colors, because the OSD is sending the right blanking voltage.

See that 75R resistor (termination) on the blanking line? Try lifting a leg to remove it from circuit, see how it goes then. That resistor might be pulling the blanking voltage too low, and I'm not sure it is needed.

EDIT: Attached schematic

[abstract3000]

I'm guessing that there is a problem with the blanking voltage. When you use the OSD it overlays the image, showing correct colors, because the OSD is sending the right blanking voltage.

See that 75R resistor (termination) on the blanking line? Try lifting a leg to remove it from circuit, see how it goes then. That resistor might be pulling the blanking voltage too low, and I'm not sure it is needed.

EDIT: Attached schematic

You might be correct in your assumptions that the 75 Ohm Resistor is not needed, I pulled the leg from Ground and the Signal Still comes through to the TV, though my observations are as follows,

The colors are still off in some sort of fashion, The OSD menu is still damn near impossible to see, so I had to push the resistor end back to ground to see and play with the menu. I found the "Favorite Color" option is the only Picture Setting that had any noticeable effect on the picture, Contrast brightness etc. all the way up or all the way down made no visible difference. Though again when i touched the resistor to ground the screen went Black & white as pictured above where I have to set the Blanking pot to see it. Though disconnected the pot no longer works and the screen is visible.

So I'm not an electronics Expert far from actually, but hear me out. That Trim Pot that's installed grounds out to a 75 Ohm resistor so Ground Terminal -> Resistor -> Ground. My understanding is everything has to have a current and a Ground, so when I pulled up the leg, we left the Pot there without a ground rendering it useless. So what if we just take the Trim Pot Ground terminal straight to Ground bypassing the resistor all together? Then I assume the trim pot would work again with the blanking. though it might just put us back in the same boat. Scratch that, Just tried that And all I get is a Black screen as seen in previous photos, and adjust too far it turns the TV off, and nothing useful. Though without the ability to adjust the blanking Signal it should be noted that I no longer have the ability to use the S-Video Input.

I also might just be thinking about this in a very stupid fashion, and you can slap some sense into me if that's the case but man I tell you those Whites are Bright!!!! Like "OverPowering" Bright, like it might be so damn bright its overriding the darker colors... The Ultimarc Board is what's feeding the power through, wondering if there is a way to "Adjust" the amount of voltage it's feeding to try and potentially bring it down :/ though what I'm thinking might be way off...

So it appears Grey is the Magic color (Adam Duritz would be so proud)


I'm going to study the manual a bit more and test this menu options out but i have it available to begin adjusting and can see it

As for the Color Issues, I grabbed the Paperboy rom and loaded it up again and here we are in the same place :/ though the windows menus and Icons are easier to read...


I also noticed this is a very strange color difference on Bubble bobble, so I can't really say where the issue is with what color....

[Zebidee]

You might be correct in your assumptions that the 75 Ohm Resistor is not needed, I pulled the leg from Ground and the Signal Still comes through to the TV, though my observations are as follows,

...

So I'm not an electronics Expert far from actually, but hear me out. That Trim Pot that's installed grounds out to a 75 Ohm resistor so Ground Terminal -> Resistor -> Ground. My understanding is everything has to have a current and a Ground, so when I pulled up the leg, we left the Pot there without a ground rendering it useless. So what if we just take the Trim Pot Ground terminal straight to Ground bypassing the resistor all together? Then I assume the trim pot would work again with the blanking. though it might just put us back in the same boat. Scratch that, Just tried that And all I get is a Black screen as seen in previous photos, and adjust too far it turns the TV off, and nothing useful. Though without the ability to adjust the blanking Signal it should be noted that I no longer have the ability to use the S-Video Input.

The pot has three legs, but looks like you are only using two. Connect the third leg, through that 75R resistor, to GND (may be easier to just use a new resistor). This should give you proper control over the blanking voltage level.

I've re-drawn the schematic and attached it below. The 75R should be attached to the "wiper", not to the output.

I also might just be thinking about this in a very stupid fashion, and you can slap some sense into me if that's the case but man I tell you those Whites are Bright!!!! Like "OverPowering" Bright, like it might be so damn bright its overriding the darker colors... The Ultimarc Board is what's feeding the power through, wondering if there is a way to "Adjust" the amount of voltage it's feeding to try and potentially bring it down :/ though what I'm thinking might be way off...

Once you get this mod's blanking sorted out, if that ever happens, maybe try it without the video amp.

Otherwise, it is easy enough to make a gang of three RGB pots. 200R pots should be sufficient, and only two legs connected this time. Below is a gang of 3 x 500R pots I made for a JAMMA PCB supergun setup + GreenAntz to component-modded TV.

The pots are Bourne cermet multiturn pots - much more precise and durable than the typical cheap carbon film ones. Not that much more expensive, and I can re-use the RGB gang with other projects.


 

For more on that project:
http://forum.arcadecontrols.com/index.php/topic,165142.msg1741501.html#msg1741501

[PL1]

To be clear, are 5v and the 75 Ohm resistor both connected to the wiper or is 5v not connected to the wiper?


Scott

[Zebidee]

To be clear, are 5v and the 75 Ohm resistor both connected to the wiper or is 5v not connected to the wiper?


Scott

Scott...

What are you asking exactly? You should not connecting 5v + 75R -> GND to same pin.
There are three pins, so I'm suggesting:

1) 5v input
2) GND + resistor
3) blanking output -> jungle

As usual for pots: three pins, three separate connections.

EDIT: which means like the third schematic pic you showed Scott.

After a sleep, I realise that I didn't erase the "U-turn arrow" pot symbol on the right side - I was treating that as just a pot symbol, rather than an actual connection, but now I get that it was confusing you to thinking the 5v was meant to be attached to both the input and wiper pins (though that seems crazy). So like this:





I don't think it really matters which way around the blanking and GND pins are, or what numbers you assign to which pin. So long as they are connected as described. I'm also not sure exactly how abstract3000's pot is physically wired WRT the "wiper" as the pics don't show that. The only pic he provided of the actual circuit board is from top and very low-res.

PL1: which pin do you call the "wiper"? The middle one? Does it matter (the pot works the same, just the high/low is swapped)? I don't know which pins are physically connected, but the pencil schematic only shows two pins connected.

So, with only two pins connected, the pot is just acting as a variable in-series resistor, rather than a voltage divider. I guess the pot would vary the blanking voltage a little, but not very much (and not very high). Further, the original schematic showing 75R resistor at the pot's blanking output would pull the voltage very low anyway.

So instead, attach the 75R "termination" resistor to the pot's GND pin (the one not currently connected). You don't need signal "termination" on this blanking anyway, it isn't even a video signal as such. Furthermore, I also think that re-assigning the resistor to the pot's GND connection is a good idea to protect somebody from completely shorting the PSU's 5v rail to GND through the pot. If anything, maybe a higher value resistor (say 1K) could be considered.

[PL1]

After a sleep, I realise that I didn't erase the "U-turn arrow" pot symbol on the right side - I was treating that as just a pot symbol, rather than an actual connection, but now I get that it was confusing you to thinking the 5v was meant to be attached to both the input and wiper pins (though that seems crazy).

I figured that the "crazy" connection of 5v to both the center pin and outer pin wasn't right, but you might have intended to use the pot as a variable resistor with 5v connected to the center pin and the 75 Ohm resistor providing a minimum resistance between 5v and ground.  Variable resistor + resistor = a fake pot with a non-zero minimum resistance -- the technique the KADE guys used for Atari 2600 paddles on miniConsole+.

I don't think it really matters which way around the blanking and GND pins are, or what numbers you assign to which pin. So long as they are connected as described. I'm also not sure exactly how abstract3000's pot is physically wired WRT the "wiper" as the pics don't show that. The only pic he provided of the actual circuit board is from top and very low-res.

PL1: which pin do you call the "wiper"? The middle one? Does it matter (the pot works the same, just the high/low is swapped)? I don't know which pins are physically connected, but the pencil schematic only shows two pins connected.

Wiper is always the center (#2) pin.  On a schematic, this connection point is indicated by the arrow.  As you mention, the connections to the outer pins (#1 and #3) on a pot can be swapped and it just reverses the direction you turn the knob to increase/decrease the voltage/resistance at the wiper.  Swapping connections to pins 1 and 3 does not change the resistance or voltage drop of the resistive element between them, it just changes the wiper voltage when the contact is at the blue line from 4.5v (5v on pin 1, ground on pin 3) to 0.5v. (ground on pin 1, 5v on pin 3)

The wiki has a more detailed theory of operation and this exploded view for anyone wanting to learn more about how pots work.
http://wiki.arcadecontrols.com/index.php/Analog_Encoders#How_a_potentiometer_provides_the_voltage_for_an_analog_encoder_to_measure




Scott

[abstract3000]

Thanks for the Feedback, much appreciated.

The only pic he provided of the actual circuit board is from top and very low-res.

I apologize for that, and @Scott I really couldn't tell you the correct way the Schematic is supposed to look but I got some Hi-Res photos and have described where everything is going so hopefully that will clear up the confusion

So This is the Top side, I know it's painfully obvious what I marked but just indicating what I was looking at. And the orientation of the Trim Pot


So here is the Explanation I should say for lack of better words.
(whoops I messed up, I fixed the image after closer inspection)
The Red Circles indicate the Pins on the Trim Pot

Left pin Went to the 75Ohm Resistor (Now removed) Then to Ground
Center Pin connected to Right Pin
The Right Pin Goes to a Diode, then Back to the TV Motherboard I assume to Blanking.

Here is a Closeup of the Diode


In other news I went through and tried every setting in the service menu, managed to fix the Vertical Overscan, but nothing with RGB Cuttoffs or any other setting made any sort of noticeable difference besides "tone" which did what it sounds like yet not a solution. I just saw The previous posts, but didn't get a chance to read closely through them as I wanted to get you guys the Exact information of what was happening. I will look over those now.

@Zebidee, I like your solution for adjusting the voltage, those pots you used could you provide me a link to the specific ones that would be needed on Mouser or DigiKey? and those solderless connectors I really like, what are they called for searching purposes?

[Zebidee]

I figured that the "crazy" connection of 5v to both the center pin and outer pin wasn't right, but you might have intended to use the pot as a variable resistor with 5v connected to the center pin and the 75 Ohm resistor providing a minimum resistance between 5v and ground.  Variable resistor + resistor = a fake pot with a non-zero minimum resistance -- the technique the KADE guys used for Atari 2600 paddles on miniConsole+.

Yeah, but no. There are many variants, but I'm just suggesting to make a simple voltage divider with the pot.

Putting a resistor on the GND pin, as a minimum load, is sensible. Not trying to be fancy here.

PL1: If you put a resistor between the wiper and the GND you change the behaviour of the pot (in terms of voltage response) to approximate a log curve (or is it anti-log? always confusing), rather than linear. This might well be appropriate and feel "natural" for the Atari 2600 paddles, but beyond the scope of what I'm talking about for this mod.

It just so happens that I covered this in depth (with pics, graphs & even a re-usable spreadsheet), a few months ago, on another post about decent volume controls:
http://forum.arcadecontrols.com/index.php/topic,167662.msg1765413.html#msg1765413

The wiki has a more detailed theory of operation and this exploded view for anyone wanting to learn more about how pots work.
http://wiki.arcadecontrols.com/index.php/Analog_Encoders#How_a_potentiometer_provides_the_voltage_for_an_analog_encoder_to_measure



Scott

Thanks for that link, it is a great resource. 

PS: I had just written all this then saw a new post from abstract3000, so will just submit this then read.

[PL1]

PL1: If you put a resistor between the wiper and the GND you change the behaviour of the pot (in terms of voltage response) to approximate a log curve (or is it anti-log? always confusing), rather than linear. This might well be appropriate and feel "natural" for the Atari 2600 paddles, but beyond the scope of what I'm talking about for this mod.

Different application and different connections, but it's still a combination of a pot and a fixed resistor.   

The Atari paddles have pots wired as variable resistors. (2 wires)

Arduino A/D inputs can only read voltage (not resistance) so the extra resistor was added externally so the original paddle wiring wouldn't need to be modified to make it work as a voltage divider. (pot)

 


Scott

[Zebidee]

Thanks for the Feedback, much appreciated.
...
So This is the Top side, I know it's painfully obvious what I marked but just indicating what I was looking at. And the orientation of the Trim Pot


So here is the Explanation I should say for lack of better words.

The Red Circles indicate the Pins on the Trim Pot
Left pin goes to a Jumper (No Jumping pin disconnected) The Other side of that Jumper goes to Pin 14 (H-Synch)
Center Pin Went to the 75Ohm Resistor (Now removed) Then to Ground

Oh wow this is very revealing.  A few points that were not apparent from the schematic.

1) WTF/What/why is that pot/jumper connected to VGA pin 14? That is the vertical sync pin.

It should be connected to a 5v source. On some VGA cards 5v is available from VGA pin 9. There are also 5v sources available from the TV.

2) Looks like the 75R resistor was attached to the wiper+GND originally, rather than the output+GND as the schematic says. It is still pulling the voltage very low. Try replacing it with a larger value like 1K.

The Right Pin Goes to a Diode, then Back to the TV Motherboard I assum to Blanking.

Here is a Closeup of the Diode

3) That diode is completely new news to me. It will pull the blanking voltage down even further (~0.7v). You probably don't need it there anyway, remove it [edit: easier to just bypass it with a short wire], it may be causing issues.

In other news I went through and tried every setting in the service menu, managed to fix the Vertical Overscan, but nothing with RGB Cuttoffs or any other setting made any sort of noticeable difference besides "tone" which did what it sounds like yet not a solution. I just saw The previous posts, but didn't get a chance to read closely through them as I wanted to get you guys the Exact information of what was happening. I will look over those now.

I'm not worrying about this much for now. Get the blanking right first.

@Zebidee, I like your solution for adjusting the voltage, those pots you used could you provide me a link to the specific ones that would be needed on Mouser or DigiKey? and those solderless connectors I really like, what are they called for searching purposes?

The specific pots I used are Bourne 500R, but as I mentioned above 200R would be sufficient.
https://www.bourns.com/products/trimpot-trimming-potentiometers/trimpot-trimming-potentiometers-multiturn/product/3296

To buy, search for:
"bourns cermet multi turn potentiometer 3296W-1-201LF" for the 200R variety, or;
"bourns cermet multi turn potentiometer 3296W-1-501LF" for the 500R.

I see that they are available on both Mouser and Digikey, as well as other online marketplaces.

[Zebidee]

PL1: If you put a resistor between the wiper and the GND you change the behaviour of the pot (in terms of voltage response) to approximate a log curve (or is it anti-log? always confusing), rather than linear. This might well be appropriate and feel "natural" for the Atari 2600 paddles, but beyond the scope of what I'm talking about for this mod.

Different application and different connections, but it's still a combination of a pot and a fixed resistor.   

The Atari paddles have pots wired as variable resistors. (2 wires)

Arduino A/D inputs can only read voltage (not resistance) so the extra resistor was added externally so the original paddle wiring wouldn't need to be modified to make it work as a voltage divider. (pot)

 


Scott

Right. We/You are measuring voltage not resistance. Your example has only 2 pins connected, thus it is just a single variable resistor. Even so, it works as a voltage divider because there is another resistor between output and GND.[edited, corrected, condensed]

As you say, "Different application and different connections, but it's still a combination of a pot and a fixed resistor.   ". Very true.

[abstract3000]

Oh wow this is very revealing.  A few points that were not apparent from the schematic.

1) WTF/What/why is that pot/jumper connected to VGA pin 14? That is the vertical sync pin.

It should be connected to a 5v source. On some VGA cards 5v is available from VGA pin 9. There are also 5v sources available from the TV.

Sorry please take another look at the photo, I updated my mistake. That Jumper was left on the board and I was told it was for testing, and not to bother with it. My guess is the other side is related to Pin 13 and it was when he was playing around with the Synch Signals. 

2) Looks like the 75R resistor was attached to the wiper+GND originally, rather than the output+GND as the schematic says. It is still pulling the voltage very low. Try replacing it with a larger value like 1K.

So it would have been on the Left pin not the Wiper, but I can try putting a 1K resistor in it's place instead to see what that does. The Wiper (center from my understanding is connected to the right pin)

3) That diode is completely new news to me. It will pull the blanking voltage down even further (~0.7v). You probably don't need it there anyway, remove it [edit: easier to just bypass it with a short wire], it may be causing issues.

Ok so I Can look at a way to pypass the diode completely, I was thinking the 5V may be coming from the TV to the right pin through the diode to ensure it doesn't somehow find its way back as precautionary, but I could have that completely wrong.

[Zebidee]

Oh wow this is very revealing.  A few points that were not apparent from the schematic.

1) WTF/What/why is that pot/jumper connected to VGA pin 14? That is the vertical sync pin.

It should be connected to a 5v source. On some VGA cards 5v is available from VGA pin 9. There are also 5v sources available from the TV.

Sorry please take another look at the photo, I updated my mistake. That Jumper was left on the board and I was told it was for testing, and not to bother with it. My guess is the other side is related to Pin 13 and it was when he was playing around with the Synch Signals. 

I think I understand. So VGA 13/14 is not connected or related to the blanking? Good, leave it for now.

2) Looks like the 75R resistor was attached to the wiper+GND originally, rather than the output+GND as the schematic says. It is still pulling the voltage very low. Try replacing it with a larger value like 1K.

So it would have been on the Left pin not the Wiper, but I can try putting a 1K resistor in it's place instead to see what that does. The Wiper (center from my understanding is connected to the right pin)

I'm confess to being completely confused now. As we just discussed with PL1, there are many ways to wire a pot for different outcomes. Your schematic shows the 75R+GND connected to output. This will pull your blanking voltage quite low.

One terminal is input, one is output, one is resistor->GND. Your pot is 1K? So I suggest a 1K resistor, 75R is too low.

If you had the output wired to the wiper then it would be like this:

1) 5v input
2) blanking output
3) resistor -> GND

3) That diode is completely new news to me. It will pull the blanking voltage down even further (~0.7v). You probably don't need it there anyway, remove it [edit: easier to just bypass it with a short wire], it may be causing issues.

Ok so I Can look at a way to pypass the diode completely, I was thinking the 5V may be coming from the TV to the right pin through the diode to ensure it doesn't somehow find its way back as precautionary, but I could have that completely wrong.

So.... the blanking 5v voltage is sourced from the TV somehow? Guess that's all I need to know for now.

The diode will only pass current one-way, but in doing so it drops voltage ~0.7v. I suspect that your blanking voltage doesn't get very high anyway, so this will just make it worse.

For now, don't remove the diode. Just solder a short wire (such as an offcut component leg) over the diode's terminals to bypass the diode completely. Much easier than removing the diode, and easier to undo later if you want to.

What we want to see is a large range of voltage (~0 to ~5v) at the pot's output. You can do this measurement yourself, at the pot's high/low limits, with a multimeter.

[abstract3000]

Alright then, So i get a bunch of resistors in on Tuesday, I will get the 1K resistor put back into place where the 75 Ohm one was, and solder in a wire skipping the Diode. This will also give me a couple days to try and trace the wire from the pot back to the board and see If I Can identify what exactly is happening there, and I will use the multimeter to try and get a voltage reading off of the pot.

[abstract3000]

well not the best of news, and feeling like an idiot at the moment. So I tested the 1k Resistor it did absolutely nothing, I was concerned I was not seeing anything so i used the multimeter to check the resistor and even tried a 2nd one and no dice. I then tested the 75k and it went back to how it was working previously...

So I leave the garage, and come back several hours later, Monitor is black I assumed I turned it off. What i didn't realize was that the PC shut down cutting the 12v to the Ultimarc adapter causing the screen to go black, and I went to desolder the diode and try without it....yeah so things got ugly, I see a flash on the screen and here the TV power off. At this moment I here a slight clicking sound when plugged in but no screen. My guess is with the mod on the diode I shorted out where ever it came from the board either destroying a capacitor or messing something else up in the power supply this is beyond my capabilities I'm afraid. Thank god I got the Panasonic...

[Zebidee]

RIP Sharp. Sorry for your loss. Seems like the RGB-OSD mod was causing too much pain anyway, and might never have worked well.

That clicking is likely the protection circuit cutting off power. Something is out-of-whack in the power circuit. This is probably good news as easier to repair than a shorted jungle IC. You might be able to find a failed part by backtracking the 5v supply line. If lucky maybe just a fusable resistor or power diode, easy to check these with a DMM. Sometimes the damaged part/s is obvious, sometimes not. Sometimes you can smell the "magic smoke". Maybe your mate can help.

[abstract3000]

You know my friend could certainly Troubleshoot and identify and even resolve the issue with parts being available, but at this point he appears to want nothing more to do with the project. I completely understand as he has dispensed enough time and effort to get me this far, wanting to move on to other paying jobs and leave this one behind, and that is completely understandable. To be honest I'm surprised you have stuck this out as long as you did Zebidee, and for that I am extremely grateful.

Many posts ago, I stated I needed to really consider the costs and initiative to this project, and where to draw a line. So far its just putting more money and effort on trying to find that "fix", I feel like such a complete idiot and should have physically checked the TV was unplugged, but its just another reminder to move on, with several red flags along the way.

I can't help but feel deflated and a bit of a hit to my ego, as I truly am fascinated with Electronics, never thought i knew to terribly much, but never thought i would make this blunderus of a move out of carelessness. Though wakabavideo's adapter is in Los Angeles Right now on it's way and I have a direct swap over. So as hard as it is to just let it go, I feel it's time to put this to bed, use the other Monitor with the plug and play option (verified on a cheap Chinese adapter) and stop dumping money into it.

If the CRT will fit into the Panasonic Housing by chance (I have little faith that it will (but if so) I will hold onto it a bit longer as it will be easier to store and maybe down the road i can have another look. Though if not I just can't have that CRT in the massive temporary wooden frame sitting around exposed, it's hard to move and not well protected, and letting it take all that space up for an inevitable event the neck gets broken by accident seems wasteful, but I will see how it goes this weakened.

[Zebidee]

Argh. Nevermind. To screwup is human. Ego takes a beating, but it will recover. Learn from mistakes. Time to move on. At least you didn't fry.

Offer the Sharp for free online, here and elsewhere.

If you measure the CRT's yoke impedance, you can attract interest from people wanting to do a tube swap.

Just set DMM to ohms (set to low ohms if not autoranging) and get the readings across both horizontal and vertical yoke coils. You can access the large pins near neck. Alternatively, you can unplug the 4-pin chassis connector and put your probe leads into the female pins. This ensures a good connection.

Good idea to zero the meter's probes first (hold probe leads together for a few seconds, let readings approach zero/settle), as the horz coil readings in particular can be quite low in some yokes, and a few ohms difference can be important.

When done, stick down some paper/masking tape somewhere convenient, and write down the H & V coil readings on it.

You'll also need to count the number of pins around back of neck (you may need to remove the neckboard to see clearly).