RGB Mod TV - Jumping off point

[Alaska]

I have been looking into modding a TV to accept RGB for awhile now. I am new to the topic but have come across some helpful links that provide details regarding this mod. I hope these links help others find a jumping off point if they are interested in doing an RGB mod. Anyone who has anything to add, please comment below!

Background info on RGB.
https://www.retrorgb.com/rgbguide.html

Ton of builds and Q&As
https://shmups.system11.org/viewtopic.php?f=6&t=561551

In Search of Scanlines: The Best CRT Monitor for Retro Gaming ~ Article by Wesley Fenlon
https://www.tested.com/tech/gaming/456719-best-crt-retro-games/

Videos on RGB mods
Part 1

Part 2 - VGA input

Sony Trinitron Mod using Closed Caption


Sony Mod with locked BLK
https://www.instagram.com/p/B7OIe0lBHzG/?igshid=1w1sa8xyjemlv

NTSC TV RGB Input Hack ~Michael Moffit
http://mikejmoffitt.com/articles/0032-tvrgb.html]http://mikejmoffitt.com/articles/0032-tvrgb.html]http://mikejmoffitt.com/articles/0032-tvrgb.html

DIY circuit to convert VGA to composite sync
https://www.epanorama.net/circuits/vga2rgbs.html
Another solution presented below - use separate 500R resitors and 1k potentiometers for the H and V sync, then combine and connect to composite input

Types of RGB Mods:

Feed RGB to an unused/extra input in the Jungle Chip that is not associated with the on screen display (OSD). Example in the third video above where the closed caption board was modified to dish RGB from a console into the Jungle. RGB input must be analog!

Feed RGB through the OSD to the Jungle IC. This is a bit more involved as you will have to enable the OSD by feeding a constant voltage (typically 5V) through the blanking line associated with the OSD. Otherwise your RGB will show up inside of the OSD lettering. Also, a toggle switch will likely be needed to enable the OSD to make screen adjustments. This can be done using a 4pdt switch (4 inputs, three lines, RGB + BLK for your feed and the native OSD).

Feed directly to the neckboard. This is not optimal and not for noobs. It is much easier to find a different CRT than attempt this hack unless you are very experienced in TV repair and have the proper equipment.

[buttersoft]

The best place to go for RGb-modding advice is hands-down the shmups thread. There's a like 90 pages, but it will answer every question, and if not you can ask politely and get an answer

https://shmups.system11.org/viewtopic.php?f=6&t=56155

IT's actually easier to feed RGB straight to the neckboard than anything else, but still not recommended as if you do it wrong you're nonstop dosing yourself with x-rays.

EDIT: Alright, my detector was faulty. Luke Evans Simon has pretty much proved how hard it is to increase x-ray production. Using a neckboard mod is still a second-best option though, as it bypasses HV regulation which can leave to funny thing happening to the picture like line droop and field tilt (sic).

Also, that sync combiner is unnecessarily complex. Easiest is simply to use crt_emudriver and output composite sync directly from your GPU. After that, using a 500R resistor and a 1k potentiometer in each line, then combining the two, is all that's needed. There are edges cases, but 99% of the time that will work perfectly.

[nipsmg]

The vast, vast majority of mods (especially on US NTSC TVs) will be leveraging the OSD Mux method.  By far, the easiest chassis to mod is the BA-5D chassis (Trinitron KV-FS100, KV-FS210, KV-FV300, KV-FV310.  These were popular TVs and show up often for cheap. The mod requires you to remove the board, take off some very small surface mount resistors, then everything else is just soldering to completely exposed topside jumpers. No pulling legs of resistors or capacitors, no other mods to the board or existing components.

Here is my mod with detailed instructions:

https://shmups.system11.org/viewtopic.php?f=6&t=63622&start=78

Note, read up on discharging tubes.  It’s really not very hard, but make absolutely sure you do it and do it two or 3 times just to be safe.  Once you get that, the rest is easy. 

[Alaska]

Also, that sync combiner is unnecessarily complex. Easiest is simply to use crt_emudriver and output composite sync directly from your GPU. After that, using a 500R resistor and a 1k potentiometer in each line, then combining the two, is all that's needed. There are edges cases, but 99% of the time that will work perfectly.

Thanks! Essentially if someone wants to combine syncs, they would need to run H and V sync individually from the VGA leads to their own 500 ohm resistor then to a1k potentiometer (three leads, input sync with resitor, output, gnd), then combine the leads and connect the composite signal the composite input? Genius as this would allow for the signal to be 'tuned' in case there is a discrepancy in resistance or voltage.

[buttersoft]

Yes, something like that. Most of the time tuning isn't needed, but occasionally it helps. And extron or similar device will do the same job easier, but is much more expensive to start with.

[MiteWiseacre]

My vga to rgb worked fine combining H&V sync to a 75ohm terminated to ground resistor. Looks great

[morton]

Hey Nipsmg... do you advise these as being the best models to RGB mod? Any issues or caveats with the results? They're definitely abundant. Am thinking of giving it a shot.

[Alaska]

Here is my mod with detailed instructions:

https://shmups.system11.org/viewtopic.php?f=6&t=63622&start=78

Note, read up on discharging tubes.  It’s really not very hard, but make absolutely sure you do it and do it two or 3 times just to be safe.  Once you get that, the rest is easy. 

It looks like you grounded all of your mods to the S Video ground, is that correct? I was wondering where to run the GND lines, the board or the VGA and was considering just using the VGA ground terminal. This would then have the GND from the potentiometers associated with the H and V sync and the 75ohm to GND from the R/G/B signal running back to the VGA GND. Wiring diagram attached, but GND is not specified yet for potentiometer or a grounding source for the 75ohm - GND... just a generic GND

[Alaska]

Hey Nipsmg... do you advise these as being the best models to RGB mod? Any issues or caveats with the results? They're definitely abundant. Am thinking of giving it a shot.

Sony's with the BA-5D chassis are definitely the most documented for an RGB mod. The link Nipsmg provided has numerous walkthroughs and troubleshooting. Here is a list of Sony models with that chassis:
KV-27FS100
KV-27FS210
KV-27FV300
KV-27FV310
KV-29FA210
KV-29FS100
KV-29FS100
KV-29FV300
KV-29FV300
KV-29FV310
KV-32FS100
KV-32FS200
KV-32FS210
KV-32FV300
KV-32FV310
KV-34FS100
KV-34FS100
KV-34FV250
KV-34FV310
KV-36FS100
KV-36FS200
KV-36FS210
KV-36FV300
KV-36FV310
KV-38FS200
KV-38FV250
KV-38FV310

[bobbyb13]

Although I don't know exactly what chassis they are, I have a few Sony sets that I have been wanting to (and afraid to) mod, so hopefully I can find the motivation/balls to give this a shot finally.

Thank you all for posting!

Bobby

[nipsmg]

Reach out if you need help.  That thread over there is hit or miss with people helping.   Sometimes its great, sometimes radio silence.

[Arroyo]

Just something to note (as Nipsmg can attest), those Sony’s are great for console games but not so great as arcade monitors.  That chassis and a few others from Sony from that time period do not like to go much below 60hz, and therefore there are a number of games that if you try to play in their native refresh rate will give you a wobbly or un-viewable picture.

[abispac]

I want mine for mostly arcade stuff, would i better go to find an arcade monitor? as 15khz would be a pian in the ass to achieve?

[Arroyo]

I want mine for mostly arcade stuff, would i better go to find an arcade monitor? as 15khz would be a pian in the ass to achieve?

Arcade monitors are certainly ideal for their flexibility in refresh rates and easy analog potentiometer screen adjustments (geometry, size, etc).  Having said that, there are certainly plenty of other TV's that have a flexible chassis, however most if not all will require you to go into the settings of the OSD to make adjustments to the picture (a bit more of a pain). 

Not sure what you mean by 15khz will be a pain in the ass to achieve?

[abispac]

I want mine for mostly arcade stuff, would i better go to find an arcade monitor? as 15khz would be a pian in the ass to achieve?

Arcade monitors are certainly ideal for their flexibility in refresh rates and easy analog potentiometer screen adjustments (geometry, size, etc).  Having said that, there are certainly plenty of other TV's that have a flexible chassis, however most if not all will require you to go into the settings of the OSD to make adjustments to the picture (a bit more of a pain). 

Not sure what you mean by 15khz will be a pain in the ass to achieve?

Arcade games, (even if you use emudrivers with groovymame or groovyarcade) run at 15khz, so, ive seen this tv hacks are mostly for consoles or pcs without the 15khz mode (aka,emufrivers or groovyarcade), so if my pc uses emudrivers to achieve the 15khz (which is ok for aracdemonitors) will i have a problem on the tvs monitors hacked? hope i explained myself on this one.

[Arroyo]

hope i explained myself on this one.

Let’s take this offline, don’t want to derail Alaska’s thread.  PM incoming.

[abispac]

Can we make our own help thread here as that forum takes ages for someone to reply?
Anyway, i got a sony triniton kvxxxx (stiker was pilled off) with a BA-5 chassis, and thanks to this guy i kind know what to do, https://shmups.system11.org/viewtopic.php?f=6&t=63622&start=180
this are his images
https://imgur.com/a/lZTtECe
Now, i dont know how to build a little tiny board like him, so i dont mind splicing and soldering cables instead, and thats the part i get lost. i think i can do this.
On his picture, the single brown and orange cable, thats for the switch rigth? and i can see theres a resistor right there, so according to this image

it should be a 2k2 resistor.

and thanks to this image i know where to solder them.

Now instead of using a fancy board like him, can someone please explain to me how to do the rest of the cables please. i think they go like this.



Solder cables at
jw343  B----------------910r------------75r that goes to ground----------this end can get connected to rgb vga breakout cable
jw342  G----------------910r------------75r that goes to ground----------this end can get connected to rgb vga breakout cable
jw341  R----------------910r------------75r that goes to ground----------this end can get connected to rgb vga breakout cable

and the sync cables should go to the composite video outlet of the tv.
is it really this simple?

Also heres a message from him answering an old question, like a year ago.

RGB inline resistors are 910ohms.
2K2ohm on a 5v line for blanking.

"Jumpers for the RGB lines are as follows -
R - JW341
G - JW342
B - JW343

I got 5V from CN006 Pin 7, and blanking goes to the cathode of D003. Im sure there are top side jumpers that could be used but I didn't look.
I used 910 Ohm inline resistors, 75 Ohm terminations, and removed R086, R087 and R088. I hate surface mount components haha.

I wired everything up to molex connectors for easy case removal, and to use either VGA for a Dreamcast @15k, or a SCART connector if and when I get something that uses it.

Would switching sync to Luma on S-Video or Component fix the left shift of the image? I just wired to composite video as thats what I'd used on the other few TVs I had modded.

Pictures here -

Well i guess i just want to confirm this. one thing that gets me confused, on my vga breakout cable, i always use the ground cables to ground, so should i also get a ground straight from the chassis?  and, do i need to add anything to  my breakout cable as the 8bit guy did on his second video? usually with arcade monitors im good running the cables straight., thanks in advance for any help.

PS: theres another guy with the same model that had problems with his picture, and he had to add 220uf caps, but he dindt mention where.

[nipsmg]

that 75Ohm -> ground for the vga cables needs to be a ground in the video loop somewhere.  I used the ground pin on the back of the svideo connector.

if you need caps, they'd be inline before connection to the jungle chip (so before the jumpers)  Try without first.

[abispac]

that 75Ohm -> ground for the vga cables needs to be a ground in the video loop somewhere.  I used the ground pin on the back of the svideo connector.

if you need caps, they'd be inline before connection to the jungle chip (so before the jumpers)  Try without first.

So i got most of it right , i just need to send the ground from the 75 ohm to a ground on a video outlet then? thanks. ill post results later on.

[abispac]

Ima have to wait on this one, as i cant find any 910 oms resistors locally.

[pbj]

You know you can put resistors in series....right?

[abispac]

You know you can put resistors in series....right?

no i dont, can you tell me a conbination for 920Ohm?
Thanks

[pbj]

You should be able to get 680 ohm resistors... they’re very common.

Twist legs of two of them together and then put a third in series... 1,020 ohms which is likely close enough.

Or find some 68 ohm resistors, again very common, put 3 in series and then add a 680 ohm in series.. 884 ohms or, again, close enough.

Get some resistors and a multimeter and play around, man.  You can figure this out.

 

[PL1]

Ima have to wait on this one, as i cant find any 910 oms resistors locally.

That's not a very common value -- found in 5% or better tolerance resistors.
- 5%, 2%, and 1% tolerance values.  http://www.rfcafe.com/references/electrical/resistor-values.htm
- 20% and 10% tolerance values. https://www.engineeringtoolbox.com/resistors-standard-values-d_1659.html

You know you can put resistors in series....right?

no i dont, can you tell me a conbination for 920Ohm?
Thanks

I thought they were supposed to be 910 ohms -- 920 ohms is a non-standard value.

A 430 ohm and a 470 ohm resistor in series add up to to 900 ohms.   

If you don't have the right value resistors to add up in series, there are handy parallel resistor diagrams, formulas, and calculator at https://www.engineeringtoolbox.com/resistance-serial-parallel-connections-d_1881.html.


Scott
EDIT: Not sure what the max % tolerance is for the resistors in your mod.  Most common resistors are 20% or 10%.

[abispac]

is this the correct way to add 1k pots to the mod? green is ground,white its out, blue with 500ohm resistor is in.

[abispac]

Can someone explain to me whats the point on the 5v or 3v o less at the jungle chip? I ask  because i though that the point was to  show the video at the tv without the use of the mirco chip, and also to be able to display the osd menu when needed. I ask because for me on my recent tv mod, i can still see the  osd menu, if i turn it off, the video also turns off. im using the 8bit guy method. Thaks for your time.

[buttersoft]

MarkOZLAD's OSD mux method is to be preferred, as this muxes your external RGB with the set's OSD properly, keeping both available at once.

The switches were the previous method, allowing you to choose between the OSD and your injected RGB signal, if they were set up right. The reason you didn't just join the two inputs was because it might have negative effects on signal quality.

The SCART standard, such as it is, expects about 3VDC as a blanking input. Most of the time anything from about 2V to 5V+ was fine, however some jungle chips would respond differently to different voltages. In an extreme case you might have a chip that has RGB off at 0V, half-tone at 0.7V or so, blanking for external RGB at 2V, and then RGB off again at 4V to allow some sort of signal muxing after the jungle chip but before the neckboard. I'm not sure if all those ever needed to exist on the one jungle chip though.

[lettuce]

So ive just gotten a Panasonic Broadcast monitor that only supports composite and S-Video, its doesnt have an OSD however. Can Monitors that dont have a OSD still be modded for RGB??

[Zebidee]

So ive just gotten a Panasonic Broadcast monitor that only supports composite and S-Video, its does have an OSD however. Can Monitors that dont have a OSD still be modded for RGB??

Sure they can, RGB via OSD is just one method.

Best to look for primary inputs to the jungle first.

[lettuce]

Ah so even if a monitor doesn't have an OSD it will still have the jungle chip??

[Zebidee]

Pretty much any TV built in the last 40 years or so will have a jungle chip.

Usually there is also a separate OSD chip which feeds an RGB signal into the jungle. You can hijack that input with a little bit of cleverness, a few resistors/capacitors and maybe a switch. However some newer TVs have the OSD function incorporated into the jungle chip, denying that as an access point.

Jungle chips will obviously all have video inputs, but not necessarily RGB inputs. It is common to see primary inputs for composite video, maybe RF, but there are often svideo (Y/C) and/or component (YUV or YCbCr or YPbPr) pins available even if they aren't used. Sometimes you get lucky and find jungles with primary inputs for RGB, especially if made for the European market.

If you have a newer TV with OSD incorporated in the jungle and no RGB inputs, you'll probably have component inputs there.  If you have access to a decent RGB to component transcoder like a GreenAntz then this is a good and easy option.

Otherwise, if there are no RGB inputs anywhere else, you'll need to inject the RGB to the neckboard inputs (ie RGB outputs from the jungle). This is the dodgiest way to do an RGB mod - it is definitely possible, but not for the faint hearted or new players. Main issue is you won't know what levels the signals need to be. Secondary issue is you lose any ability to use the OSD or remote to influence or select the signals. Could be operational safety issues as well.

[lettuce]

Thanks. Ill take some detail shoots of the board and see if anything can be identified.

Im not sure how old it is, but it must be fairy old as it doesnt have an OSD, but came from a company how said they never really used it. And from the quality of the picture i find that to be true, just be noce if its possible to get RGB out of it.

The S-Video signal is nice however...

[Zebidee]

Everything will just be theory and fluff unless you add some details about your display, like brand and model number.