CPS1 Graphic faults / glitches

Hey guys, I've recently gotten into some CPS1 games and a couple of the sets I've gotten recently have some graphic faults and wondering if anyone could shed some light on troubleshooting them.

First is Final Fight. You can see that the barrel sprites have lines through them. This is also present on the character sprites but only when inputting attacks, jumps, etc. moving around they're fine. Enemies occasionaly have the lines through their sprites, always when they're getting attacked. I've removed, cleaned and reseated all of the roms on the B board, and also reseated the A board. No luck, lines are still there. I've also noted that the game's colours are off, unless I raise the JAMMA harness slightly, like it needs something underneath it to prop it otherwise one of the R, G or B components is not registering. Even with the colours correct the sprites still display funny.

Second one is Knights of the Round. I purchased this one knowing it had issues, at least with the A board. On booting up the game it would just display the initial boot screen and hang there. I swapped it into the Final Fight A board and the game boots, sound is all good but the are large graphic glitches which can be seen in the image below. Lines through the sprites like in Final Fight and a mass of sprites over the left of the screen which are persistent throughout. The only time mass of sprite shadows can't be seen is on the title splash. They're there in the intro, demo and in game.

I have a feeling the issue may be the A board of both games, I have a fully working A board packed up which I need to test with to completely rule out the fault lying with the motherboards, but I thought someone here may be able to offer up some advice - CPS is still all very new to me.

Hey, it seems these CPS boards are not easy to fix . I also have a Final Fight with sprites issues (different from yours) and these things were suggested to me:

1. Take the ROM chips and test them against the MAME set. If one does not match, burn it again and test.
2. Replace the RAM memory. It's not easy to do, I have not done it but it was suggested.
3. Replace the PAL chips. There are like 6 or 7 of those on a PCS1 board.
4. Start replacing boards from known-working sets until you at least get the broken board (using your known-good A board to test if the problem goes away)-

Sorry not being of more help.

Good advice above. I would have said the first thing to try with FF would have been the GFX mask roms, but if you're getting the same lines with your Knights of the Round B board that would suggest that it is more likely an A board fault. If you have a programmer read the GFX mask roms from your B board just to confirm they are good and then go from there.

CPS1 boards are a pain to fix unfortunately.

Ok, that is good advice guys. I've got to start somewhere I guess, I should probably look at getting a logic probe and a programmer. I'll dig out that known working A board and see if that produces any better results.

F4U57 said:

Ok, that is good advice guys. I've got to start somewhere I guess, I should probably look at getting a logic probe and a programmer. I'll dig out that known working A board and see if that produces any better results.

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Remember that different games have different PAL chips, so you may want to check your working A board is compatible with the games you are trying to diagnose. Or at least transplant the PAL chips, but if the problem is one of them, that may give false indications of the problem.

Regards.

Yeah right, from my understanding A boards are all interchangeable, no?

F4U57 said:

Yeah right, from my understanding A boards are all interchangeable, no?

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This is my understanding of it as well. And from all the B & C boards I had (6 games) a single A board worked with all of them. There are 2 different A types of A boards - one with a standard 10mhz crystal for the 68000, the 'dash' variant that had a 12mhz crystal - but all games should work with either, albeit slightly faster if you play certain games on a 12mhz A board.

FF: prob. "C" board fault.

KOR: prob "A" board fault.

pulstar said:

This is my understanding of it as well. And from all the B & C boards I had (6 games) a single A board worked with all of them. There are 2 different A types of A boards - one with a standard 10mhz crystal for the 68000, the 'dash' variant that had a 12mhz crystal - but all games should work with either, albeit slightly faster if you play certain games on a 12mhz A board.

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Yes all A boards work with all cps1 games. 99% of the time the culprit is the A board. I have way more working B and C boards then A boards at this point. I seem to average 1 A board failing a year right now. They get played a lot though as I love cps1 games :-) whatever happened to the multi cps1 B board that came out last year? Is it still limited to only being sold in France?

Westcb said:

Yes all A boards work with all cps1 games. 99% of the time the culprit is the A board. I have way more working B and C boards then A boards at this point. I seem to average 1 A board failing a year right now. They get played a lot though as I love cps1 games :-) whatever happened to the multi cps1 B board that came out last year? Is it still limited to only being sold in France?

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Yeah unfortunately it's still limited to France afaik.

too bad CPS2 currently doesn't play CPS1 games.. but that would be awesome and will definitely a big hardware PLUS for using the CPS2 platform...

....Darksoft, GET ON IT

I found out something very interesting about CPS1 mobos recently. A lot of the problems I see with them are the ram that have broken solder joints.

Fox1 said:

I found out something very interesting about CPS1 mobos recently. A lot of the problems I see with them are the ram that have broken solder joints.

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Interesting info, I have a Final Fight with a broken A board (graphic issues).

Westcb said:

Yes all A boards work with all cps1 games. 99% of the time the culprit is the A board. I have way more working B and C boards then A boards at this point. I seem to average 1 A board failing a year right now. They get played a lot though as I love cps1 games :-) whatever happened to the multi cps1 B board that came out last year? Is it still limited to only being sold in France?

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I had no idea of this, it was my understanding that the PAL chips were different between different games and since some PALs go in the A board, it was required to transplant them for the game to work.

Regards.

The ZIP ram are notorious for having broken joints due to their construction.