CPS1 Motherboard (A board) Spriteram / Objectrams?

bytestorm

bytestorm

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Hi!
I got a final fight board that works except that the characters clothes are in the wrong colours, and the sprites looks a little corrupted sometimes.

I swapped the B+C board with MERCS and the same problems occur in MERCS too, so its probably a RAM related problem in the A board.

But my question is, how can I find out with group of rams that handles the objects in the foreground? there are quite many ram ics on the A board..

Any tips?

Please see the attached picture :) DAMND and Haggars clothes has wrong color... Guy seems to be in order thou?

ff_small.jpg
 
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Xian Xi

Xian Xi

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That's usually a C board problem. If you lift the C board a little on one of the corners the problem should go away.
 
bytestorm

bytestorm

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Hmm c board.. I didn't think that both games would have same faults on their c boards, but I only have 1 A board so I can't prove that they actually works. I will inspect both the C boards. But what does the c board do actually? If I lift it a little in the corner and it goes away?? Then I guess the pins on the custom ic on the C board would need reflowing?

Thanks!
 
Xian Xi

Xian Xi

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bytestorm said:
Hmm c board.. I didn't think that both games would have same faults on their c boards, but I only have 1 A board so I can't prove that they actually works. I will inspect both the C boards. But what does the c board do actually? If I lift it a little in the corner and it goes away?? Then I guess the pins on the custom ic on the C board would need reflowing?

Thanks!
Click to expand...

It would be what the C board is connected to on the A board. Does the game pass all the tests?
 
bytestorm

bytestorm

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I tried lifting the C board in all corners, and I did get similar effects on the rest of the background, characters, objects.. couldnt get the original ones to go away thou.. hmm.
The game passes all the tests, have been cleaned, and all roms dumped and checked. Continuity has been checked in all sockets. I will try and resolder the rest of the pins of the C board, but the IC will have to wait until I get to my soldering station at work.. :( aint got no flux home either.
 
Xian Xi

Xian Xi

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You need to check the A board itself but follow where the traces from the C board go. Might be a broken trace if both games are affected.
 
bytestorm

bytestorm

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didnt make any difference. but atleast its out of the question for now.
Yes both games are affected by this color problem.

In both Final Fight and Mercs its mainly the characters that has the wrong colors.

And as the game moves on the problem is sometimes gone.. but just really quick, then flashing back to this golden strange color..
To bad that i dont have any other workin A board.. the only spare one i have, is stuck in watchdog x(

well, time to examine the A board :)
 
Tyranix95

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bytestorm said:
... I swapped the B+C board with MERCS and the same problems occur in MERCS too, so its probably a RAM related problem in the A board. ...
Click to expand...

MERCS and FINAL FIGHT have different "C" boards. So, These are incompatible replacement parts.

And, yeah, MERCS and FINAL FIGHT have the same "B" boards. But, the two boards are configured differently. So you can't swap over the socket chips and get the other game just work.

The only board you could just swap between the two boards is the bottom "A" board.
 
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bytestorm

bytestorm

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Tyranix95 said:
MERCS and FINAL FIGHT have different "C" boards. So, These are incompatible replacement parts.

And, yeah, MERCS and FINAL FIGHT have the same "B" boards. But, the two boards are configured differently. So you can't swap over the socket chips and get the other game just work.

The only board you could just swap between the two boards is the bottom "A" board.
Click to expand...

Maybe I missunderstod you now or you missread my text, but I did not swap any socketed chips.. as I wrote I swapped the B+C board from my Mercs :)
I have 2 complete games, but only 1 "working" motherboard.
 
bytestorm

bytestorm

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hmm did find this on the solderside of the A board.. just beside the 68k cpu. but, nothing seems to be cut, I measure below 1 ohm between the concerned points :(
aaah.. these Cps1 boards are a pain since probing them from the solderside sucks bigtime, and there is no schematics x(

ff_scratch_small.jpg
 
Tyranix95

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Capcom split the graphics functions among all three boards.

The bottom board has the common GPU.
The middle board has the roms.
The top board has specific GPU.

So, it takes all three graphics components, working right, to see good graphics.

Thus, when you have a graphics problem, you need to clear each board.

The best places to start is buy checking the Top and the bottom board, with the same type of part, from another known working game (because the custom graphics chips on those boards are the most flaky parts on the CPS1 board set and the hardest part to source and replace).

So, if you working MERCS "A" board works fine on MERS but does not clear the graphics problem on FF; then, next, you need to try a working "C" board on FF and see if that clears up the FF graphics problem.
 
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bustedstr8

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I have schematics for the smaller 2nd revision CPS1 A+B set. If you want them PM your email.

Also, if anyone wants to host these lemme know.
 
skate323k137

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I can host them unless they're insanely huge or violate copyright in some way. So long as they're legal to distribute I'll happily give them a http:// home.
 
bytestorm

bytestorm

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Tyranix95 said:
Capcom split the graphics functions among all three boards.

The bottom board has the common GPU.
The middle board has the roms.
The top board has specific GPU.

So, it takes all three graphics components, working right, to see good graphics.

Thus, when you have a graphics problem, you need to clear each board.

The best places to start is buy checking the Top and the bottom board, with the same type of part, from another known working game (because the custom graphics chips on those boards are the most flaky parts on the CPS1 board set and the hardest part to source and replace).

So, if you working MERCS "A" board works fine on MERS but does not clear the graphics problem on FF; then, next, you need to try a working "C" board on FF and see if that clears up the FF graphics problem.
Click to expand...

I see. But if I only source a known working A board then I can rule out it easy? From what I understand the A boards are fairly generic? But only some revision changes by pcb size and ram types.
Typically my other A board is t working.. Going to work some more with it when I get my workbench.

But since both games are having same graphical errors I would believe that the problem lies in the A board.
At least that's what I want to believe ;)

Anybody who has a A board for sale or cheap cps1 game? :)
 
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Tyranix95

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bytestorm said:
I see. But if I only source a known working A board then I can rule out it easy? From what I understand the A boards are fairly generic? But only some revision changes by pcb size and ram types. ...
Click to expand...

With MERCS and FINAL FIGHT: Yes, you can swap bottom "A" boards between the two board sets without issue.

If issues persist between the two boards with a known good "A" board, then you need to look at the Middle "B" and Top "C" boards next. Since you're dealing with a graphics issue, the next board you would check would be the Top "C" board.

--------

When it comes to trouble shooting, meeting up with another CAPCOM buddy who has the same games as you can help out a lot.
 
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bytestorm

bytestorm

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Tyranix95 said:
With MERCS and FINAL FIGHT: Yes, you can swap bottom "A" boards between the two board sets without issue.

If issues persist between the two boards with a known good "A" board, then you need to look at the Middle "B" and Top "C" boards next. Since you're dealing with a graphics issue, the next board you would check would be the Top "C" board.

--------

When it comes to trouble shooting, meeting up with another CAPCOM buddy who has the same games as you can help out a lot.
Click to expand...

Yeah that would been perfect but I don't know anyone close with these games :( but I will check around if someone atlest have a known working A board so I possibly could close the hunt on the b and c board :)
 
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