mercs pcb sync

[Drakon]

hey I doubt anyone will know how to fix this but I recently picked up a mercs pcb.  When hooked into my supergun it displays fine through my video capture device from the s-video out.  However on my tv certain parts of the game lost sync.  When I go into the object test menu in the bios the sync is all over the place.  And for the scene between stages it loses sync signal.  It's a really weird issue....I'm not sure how to go about fixing this problem

[viletim]

What's in the supergun?

[RGB32E]

hey I doubt anyone will know how to fix this but I recently picked up a mercs pcb.  When hooked into my supergun it displays fine through my video capture device from the s-video out.  However on my tv certain parts of the game lost sync.  When I go into the object test menu in the bios the sync is all over the place.  And for the scene between stages it loses sync signal.  It's a really weird issue....I'm not sure how to go about fixing this problem

Do you have any other CPS1 based arcade boards to determine if the issue is specific to the MERCS board?

[Drakon]

Do you have any other CPS1 based arcade boards to determine if the issue is specific to the MERCS board?

Yup that was the first thing I tried.  I put the b and c boards into the a-board from my sf2 ww pcb.  Same issue.  Turns out what's happening is "normal".  Apparently capcom cabs had fancy custom moniters.  This issue also happens with the 3 wonders pcb.  And it happens even in other arcade cabinets like an astro city.  Here's what I managed to dig up on the issue

http://hornet.homeftp.net/technical/3wonders/

so basically there's nothing I can really do about the problem.  But I'm just happy to find out that my mercs is functioning 100% the way it should.  And it's still completely playable since only the part between stages is messed up

[ken_cinder]

There's nothing special about the monitors used for these games.........not even close. Capcom used your standard fare Wells Gardner and other major name monitors in most cases, and this game doesn't even have the oddball sync timings some Midway games do.

I point the finger at your Supergun or the A board(Hell I'd bet on this over the Supergun if other Jamma games work fine), and I do it while owning 5 arcade machines and 6 monitors (Twin Nanao's in my Versus City). Now if this was a Medium Res game, I'd be inclined to think otherwise.....

[RGB32E]

Not that this will help you, but I'd like to share my CPS1 experiences.  I've connected at least 4 different CPS1 games (Final Fight, 2 diff Striders, and SF2:HF) and have not encountered any sync/picture stability issues. 

Configs:
-R,G,B,S, and video ground to a PVM-2030 (RGB input with ~160 ohm series resistors on RGB)
-RGB to Y/C using a Micomsoft XAV2s to a Sony CRT TV
-RGB to Y/C using an Analog Devices AD725 eval board to a Sony CRT TV
-RGB to Y/C using the POS RGB encoder PCB that came with my MAS Super Nova (circa 1998) to a Sony CRT TV

So, are you using the video ground from pin 14 on the jamma harness (next to blue output)? 

[Drakon]

There's nothing special about the monitors used for these games.........not even close. Capcom used your standard fare Wells Gardner and other major name monitors in most cases, and this game doesn't even have the oddball sync timings some Midway games do.

I point the finger at your Supergun or the A board(Hell I'd bet on this over the Supergun if other Jamma games work fine), and I do it while owning 5 arcade machines and 6 monitors (Twin Nanao's in my Versus City). Now if this was a Medium Res game, I'd be inclined to think otherwise.....

the first thing I did was switch the a-board with my sf2 a-board and had the exact same thing happen.  And my sf2 doesn't have any problems

rgb32e this problem's only been documented so far on mercs and three wonders.  I have a street fighter 2 world warrior cps1 board that plays perfectly on the same setup.  Just because the game is cps1 doesn't mean that all cps1 games will do the same thing

[XianXi]

When you say "All over the place" do you mean the sync is dirty or the sync rate fluctuates?

[RGB32E]

Well, it sounds like you'll need some sort of sync processing to "fix" the issue.  Perhaps using a JROK sync cleaner could fix your problem...?

[MKL]

The scene between stages in Mercs does appear to have issues but not a sync loss as reported by the OP. In my case the picture is perfectly steady but is very dark and only becomes normal a splitsecond before disappearing:



It may be related to the 3 Wonders problem but that doesn't show up as a sync loss either.

[Drakon]

When you say "All over the place" do you mean the sync is dirty or the sync rate fluctuates?

I mean this



Here's the same s-video signal captured through my capture card giving the famed "dark" effect



I'm assuming this's a sync issue.

[NFG]

Wow, I think that's possibly the worst sync failure I've ever seen.  O_o