Did GroovyMAME blow the sync circuit in my monitor?

[schadenfreude]

I finished setting up GroovyMAME and the custom drivers on my cool laptop setup about a week ago, and I enjoyed a few days of MAMEing it up. My setup is a notebook with a Radeon HD 7XXX running Windows 7, outputting the video signal via a VGA to 5 BNC connectors, with horizontal and vertical sync tied together with a T-connector. I haven't set up a front-end, so I am simply launching games from the command line.

The first game I tried was Makaimura, then I played some of my favorite CPS games because I planned on going through Daimakaimura soon and wanted to adjust the geometry for that system's interesting resolution. I played a few CPS games and adjusted the geometry, then decided to try Makaimura to see what it would look like to try a game with a different resolution. The moment I hit Enter to launch the game, my PVM's screen became a scrambled mess, and I quickly hit a button on the PVM to switch the input to another channel with no signal on it to protect it from possible damage.

Unfortunately, I guess I wasn't fast enough, because since then, no matter what I hook up, whether via RGB or component or composite, the image is a wavy and stormy mess, presumably because the PVM is failing to read the sync signal correctly.

At least the menus still look fine:



...but when I try any input — here, a Sega Saturn over composite — the image is a mess:



So, is there something I can check to verify that GM was outputting a valid signal when I launched Makaimura? Could this have been caused by my use of a T-connector to "combine" the syncs rather than a proper solution such as an Extron RGB or UMSA? I will say though that I played DOS games through DOSBox using the same setup for dozens of hours without issue, plus the damage seemed to occur right when I launched Makaimura. I'm also pretty sad that I received an Extron RGB last week, but it had some picture quality issues when I tested it; had it worked fine, I would have already incorporated it into my setup. Finally, does anyone know how to fix my PVM? 

[Jonny G]

For the PVM join jammaplus.co.uk find a guy called Gunblade. Monitor repair wizard.

Edit

Thinking about it, sure he has an account here too.

[Calamity]

Get a log from the command you typed when the failure happened, so we can see which modeline was being used (unplug the cable just in case).

Tying both syncs with a T-connector is far from ideal, but I have the same monitor connected the same way and have had no issues so far.

[donluca]

At least you should have put a couple resistors in line with the sync signals before tying them together.

[schadenfreude]

Don't the BNC connectors at the end of a VGA-BNC cable provide 75Ω resistance?

[schadenfreude]

Get a log from the command you typed when the failure happened, so we can see which modeline was being used (unplug the cable just in case).

I've attached the log to this post. And here are the command I ran plus the output right when the monitor flaked and I disconnected it:

Code: [Select]

C:\Users\Brandon\Desktop\MAME>groovymame.exe makaimur -ues -resolution 2560x0

SwitchRes: [makaimur] (1) horizontal (256x224@59.590000)->(2560x240@59.590000)


Tying both syncs with a T-connector is far from ideal, but I have the same monitor connected the same way and have had no issues so far.

I read this a lot and agree it's far from ideal, but then why do so many of us do it — and do it without any issues?

[buttersoft]

Don't the BNC connectors at the end of a VGA-BNC cable provide 75Ω resistance?

No, they provide effectively zero resistance. The 75R you hear about with video lines and connectors is their characteristic impedance - wikipedia can tell you what that means.

That's a ---steaming pile of meadow muffin--- about the monitor dropping sync though. PVM's are built like tanks, BVM's like battleships, but everything wears out eventually. GM won't have caused it though; and doubly not, with that log. The PVMs of that ilk have a stated 4Vp-p sync tolerance, and some BVM's go up to 8Vp-p. VGA has a 5V DC offset and a 300mVp-p range, but the DC offset would be caught by the input caps, i think. There's certainly bufferring in there, if only in the form of transistors. Which is not to say i recommend using a T-piece and feeding the sync lines directly into one another - that's normally fine for testing, but even then if you have other methods you should use them. These sets are 30 years old in some cases.

If the sync circuits in the monitor have gone, diagnosing the problem isn't straightforward as Sony never did anything the easy way and the PVM 20 and 20M series use quite complicated deflection circuitry (for a raster CRT). You'll need a scope, and parts, and luck because if it's an IC you might need to calculate an equivalent.

Hopefully it fixes itself. Leave it off for a few days and see. Keen to hear how you get on, and if Gunblade at Jammaplus.co.uk can help! I have a few PVM's beyond my ability to repair right now...

You've tried the external-sync button a few times on both composite and RGB signals, right?

[donluca]

Besides, by combining the sync signals you're more likely to blow your video card than a PVM/BVM.

I did unspeakable things to my 14M4DE and it still works perfectly. Those monitors are bomb-proof.

[buttersoft]

Those monitors are bomb-proof.

I have seven or so that say otherwise, two I've been unable to fix with my limited skills. Google will tell you about more-common problems as well. They work fine until they don't, although it might be aging components that gets them rather than user abuse

[schadenfreude]

Besides, by combining the sync signals you're more likely to blow your video card than a PVM/BVM.

Right, makes sense since using a T-connector is like shorting the H and V pins on the VGA connector.

You've tried the external-sync button a few times on both composite and RGB signals, right?

I just checked that, and it didn't help anything. But then I remembered that I messed with the geometry to get CPS games to display properly, and specifically I recall setting H FREQUENCY to a really low number to help center the image. Just now, on a whim, I pushed the value from 25 up into the 60s, booted the Saturn — and now I'm getting a clean image! My naive guess is that setting H FREQUENCY too low pushes the image too far to the left in the overscan area, which makes the gun fidgety about how to sync that image properly to the screen. I hope someone else can provide a better explanation.

In my despondent state today, I saw a 27" Sanyo CRT with component inputs at a garage sale while I was on my bike and picked it up for $10 — and I mean I returned with my car to fetch it because I am not Superman  . It seems like a ---smurfy--- unit — there isn't even a "Menu" button on the unit itself, so I need to use a universal remote! If only I had tried the above tweak earlier. But one can never have enough CRTs, and I'm not yet confident the PVM is back. 

[donluca]

I have seven or so that say otherwise, two I've been unable to fix with my limited skills. Google will tell you about more-common problems as well. They work fine until they don't, although it might be aging components that gets them rather than user abuse

It's always the capacitors, I've yet to hear/read about an IC which went bad. Caps have always been the weak link in the chain in electronics, be them professional or not.

I know I should recap mine but I'm terribly lazy and since I've got my own SEGA Astro City Cab the BVM is not seeing any action as of late.

[Dochartaigh]

Hope it's OK to bump this topic with a related question: several of you said it's bad to combine H and V sync with a T-connector. What is the proper way to do it? The only cables I see are VGA to RGBHV and my monitor needs RGBs.

I'm going from a Asus Radeon HD 6450 2GB Video Card (which I believe Calamity used to good effect), to several different PVM/BVM's and don't want to damage anything, and furthermore get a proper, stable sync.

Somebody mentioned that the video cards (maybe) can be set to output RGBs with a certain setting? Searching for "combining sync" brings up like 5,000 posts so I can't find this information anywhere!

[buttersoft]

to save myself typing the answers out again

https://www.aussiearcade.com/showthread.php/87668-A-guide-to-connecting-your-Windows-PC-to-an-SD-CRT-TV-PVM-or-Arcade-Monitor

[Dochartaigh]

to save myself typing the answers out again

https://www.aussiearcade.com/showthread.php/87668-A-guide-to-connecting-your-Windows-PC-to-an-SD-CRT-TV-PVM-or-Arcade-Monitor

Thanks man, it's late but I will definitely read that tomorrow bright and early!

[Dochartaigh]

to save myself typing the answers out again

https://www.aussiearcade.com/showthread.php/87668-A-guide-to-connecting-your-Windows-PC-to-an-SD-CRT-TV-PVM-or-Arcade-Monitor

Thank you again, but I read through that (and the comments with some more/other ideas) and it seems like the only way (if I don't want to build my own which I don't - have enough projects TBH) seems like it's a RGB interface of some sort which you said you're not that familiar with (as you wire up your own device to do this it sounds like).


My problem with using an interface like the popular Extron RGB Rxi 203 to combine the syncs, is normally people would set the Extron RGB to output 15khz, correct? Then they're stuck at outputting that 15khz unless you tell it otherwise?

My planned setup is a little different in I'm using a multiformat PVM/BVM's which can do 15khz (240p/480i), 31khz (480p), 33khz (1080i), and 47khz (720p), so with the entire point of GroovyMAME with CRT Emudriver is to get the correct resolution for every single arcade game (which I think my monitor can do all those different native resolutions), I need a sync combining device which can output the same exact signal as it's inputting - which the normal Extron Rxi 203 can't do I don't think (there is a special EDID MINDER version of the 203 which does have pass through, but I haven't ever seen one of those for sale). Any suggestions?

(and I'm sorry if I took over this thread! just trying to wade through everything - all this is very confusing when you're just starting out!)

[Paradroid]

My problem with using an interface like the popular Extron RGB Rxi 203 to combine the syncs, is normally people would set the Extron RGB to output 15khz, correct?

Nope. The Extron will work with whatever you feed it (no scan conversion). See attached specs from the manual.

[buttersoft]

There are extrons which do a straight pass-through to BNC, and will combine the sync, like the 190F. Should be cheaper than a 15kHz unit too. But then you do need to make sure you input the signal format you want to get out - 15kHz 240p in, for 15kHz 240p out, for example.

EDIT: oh, does the 203 work that way as well? Which are the downscaler models, then?

Actually, it pisses me off  that i never seem to be able to find what the extron units actually DO in their manuals. Where does that linked sheet indicate output scan rate? Does the fact the output scan rate isn't mentioned imply the input rate is not being converted? I presume the manuals for the actual downscalers  do list the output scan rates?

[Paradroid]

Does the fact the output scan rate isn't mentioned imply the input rate is not being converted?

In this case, yes: there is no scan rate conversion at all for the rxi 201/202/203 models. These units provide H and V centering along with with handy features like level and peaks controls plus sync format conversion.

[Dochartaigh]

Nope. The Extron will work with whatever you feed it (no scan conversion). See attached specs from the manual.

Thanks, I was getting confused by the manual where the special "EDID" version of the RGB Rxi 203 has a dial to select the resolution (which still doesn't downscale anything adding to my confusion)

Which are the downscaler models, then?

Can't answer your other questions, but I know the Extron VSC 500 and 700 models downscale (was looking into one of those to convert 480p into 480i for my non-HD monitors).

Question for you: you said " Some older AMD cards had the option in Catalyst Control Center to set composite sync instead of H-Sync over pin 13, giving you RGBs directly, but crt_emudriver doesn’t use CCC", but I have people reporting that CRT Emudriver 2.0 Beta, with Catalyst Control Center 13.1, that they're outputting csync on their Radeon 5450 video card...(which is near identical to the card I'm looking at).

[buttersoft]

Question for you: you said " Some older AMD cards had the option in Catalyst Control Center to set composite sync instead of H-Sync over pin 13, giving you RGBs directly, but crt_emudriver doesn’t use CCC", but I have people reporting that CRT Emudriver 2.0 Beta, with Catalyst Control Center 13.1, that they're outputting csync on their Radeon 5450 video card...(which is near identical to the card I'm looking at).

TBH I'm not sure. It used to fail. It might depend on the card? Calamity doesn't check crt_emudriver's compatibility with CCC, IRC. And for the original versions of crt_emudriver he recommends *against* using it. But if that works it'll be much easier.

Is this from Shmups? Can you link me to more info?13.1 was the version used for the original Win 7 crt_emudriver, not 2.0, so which version of crt_emudriver driver is this with? Does it only work with the 13.1-hacked version of the old crt_emudriver, and so only with 4000 series cards and older, and only on Win 7? So many questions

Sadly i'm not going to give it a go myself any time soon because i don't want to rip up my arcade setups, and my radeon laptop died, but if i can find out enough I'll update the guide

(MarkOZLAD is on shmups a lot, and he' still combining H- and V-sync himself...?)

[Paradroid]

You can use WinModelines to set composite sync (no need for Catalyst): http://www.geocities.ws/podernixie/htpc/modeline-en.html

Direct C-sync is a pain to get right. I investigated it a year or so ago because I was interested to see if I could do without sync combining hardware. I did end up getting it working but, due to the required effort and lack of C-sync support in Atom-15, I decided to stick with external sync combining.

[buttersoft]

You can use WinModelines to set composite sync (no need for Catalyst): http://www.geocities.ws/podernixie/htpc/modeline-en.html

Direct C-sync is a pain to get right. I investigated it a year or so ago because I was interested to see if I could do without sync combining hardware. I did end up getting it working but, due to the required effort and lack of C-sync support in Atom-15, I decided to stick with external sync combining.

That's great, I never knew that! Excellent point about Atom-15. Even taking that into account though, does winmodelines work for Win10 AMD cards? And can you enable c-sync by port, or only for the whole card? (Would CCC perform the same way, there?)

Those schematics for VGA-to-Arcade sync might be good, but the SCART recommendation won't work for a lot of RGB hacked TV's, and i know that because i've tried it without knowing about it. Which might mean it doesn't work with every SCART set, i'm not sure?

I really need to get a test setup again

[Dochartaigh]

I think I'm going to try to just get this built and working (with a cheap Extron RGB) before I mess with going deeper into the drivers and different modes and all - thank you for the info everyone.