CAPCOM CPS1: Squiggly Lines.

Tyranix95 · Jan 20, 2011

Hi Everyone,

Ok, I've been wanting to ask this question for a long time now.

Every now and then I see CAPCOM CPS1 boards listed on eBay with "little black squiggly lines."
The game is described as plays fine but graphics problem.

Last year I played such a game and it worked fine--except for the graphics.
I noticed that these these little squiggly black lines ran vertically across the screen.
During text screens, these little black lines always covered or distorted the text.
But, during non-text game play screens, these little squiggly black lines disappeared; however,
the character sprites were messed up (rendered incomplete).

Since then, I've sen these black lines on CPS1 games with and without a suicide battery.

So, I'm wondering if anyone knows what causes this kind of graphics problem?

-------------------- :scratch:

A) Bad CPS1 :A:

board,
B) Bad CPS1 :B:

board,
C) Bad CPS1 :C:

board,
D) Bad CPS1 :A:

board and Bad CPS1 :C:

board, or
E) All of the above, :eek_2:

jew90 · Jan 20, 2011

Likely due to a dead battery on the C board, this battery powers a "CPS-BXX" Chip.

When the battery dies the graphics don't display properly anymore.

You can revive most if not all of them by removing the battery, little bit of modding and patching some of the roms.

Post 92 boards that have Q sound have 2 batteries on them, the above and one to power the Q sound board. Either one dying will cause problems

Once the above battery(s) are verifyed working / repaired any other issues are most likely hardware fault(s).

If it is strictly battery issues they are straightforward to repair if you have the tools and an eprom programmer.

Oh and obviously, if it is a board without a battery, then it is a hardware fault. This could be somethign simple like a bad connection between the boards, a broken trace or somethign more serious like faulty chip(s).

Xian Xi · Jan 20, 2011

jew90 said:
Likely due to a dead battery on the C board, this battery powers a "CPS-BXX" Chip.

When the battery dies the graphics don't display properly anymore.

You can revive most if not all of them by removing the battery, little bit of modding and patching some of the roms.

Post 92 boards that have Q sound have 2 batteries on them, the above and one to power the Q sound board. Either one dying will cause problems

Once the above battery(s) are verifyed working / repaired any other issues are most likely hardware fault(s).

If it is strictly battery issues they are straightforward to repair if you have the tools and an eprom programmer.

Oh and obviously, if it is a board without a battery, then it is a hardware fault. This could be somethign simple like a bad connection between the boards, a broken trace or somethign more serious like faulty chip(s).

Not all C boards have a battery though. The CPS-BXX chip could just be going bad. You can use another one from a donor board, some games use the same CPS-BXX IC.

Hewitson · Jan 20, 2011

Fuck I hate Crapcom boards. They've made some damn good games, but they deserve to go out of business for making so much self destructing hardware.

Kyuusaku · Jan 20, 2011

It sounds like something with the B & C board. Normally vertical lines corresponds to a bad data line but graphics data is contiguous on CPS so that would affect sprites too, not just a background layer. The chip on the C board makes up half of the video controller, I believe it multiplexes the character data and sends it back to the A board. You can try reseating the boards but if that doesn't fix it there has to be a broken trace... Or maybe someone exchanged the C board from another game...

Tyranix95 · Jan 21, 2011

HA! Good point Hewitson: CAPCOM did published some good games with some bad parts. :lolz:

I think CAPCOM designed their CPS around composite components rather than unit longevity.

I guess composite parts are supposed to be easy to mass produce and easy to replace--just like my computer.

-----

Xian Xi has a g :eye:

d point too.

The messed up game that I played was a CAPCOM FINAL FIGHT (US). And that game does not have a suicide battery.

When I played that game, I thought it had either a bad connection between the boards or a bad C board.

I got to visually inspected the game boards.
I saw no obvious signs of damage; however, the boards looked clan—real clean—not like a cave board. :scratch:

I also got to separated the :A:

,

, &

boards; clean the CN pins with Isopropyl Alcohol and a toothbrush; and reseat the bards. The CN pins looked real clean too. Seems my effort was futile because, upon reboot, the little black squiggly lines and corrupted sprites reappeared on screen same as before. :scratch:

I didn’t get to do any further testing--mainly because I didn't have any other CAPCOM parts or test equipment available.

-----

, I found a PCB with a "comparable graphics problem."

It's a CAPCOM Kinghtns of the Round. The board has a suicide battery--Looks undamaged--And Real clean. But, these black lines are not squiggly.

(Cf. Knights Of The Round with no graphics problem.)

Any ideas?

channelmaniac · Jan 21, 2011

I've seen more A board problems than B or C board problems when it comes to corrupt graphics. Look at the bottom of the A board for scratched or gouged traces. Bad RAM on it will cause the issue too - and don't believe the RAM tests when they say the RAM is good.

RJ

Tyranix95 · Jan 21, 2011

channelmaniac has a great point: Vendor’s RAM tests do not test some graphics chips.

I remember the FF game booted fast without any error messages.

I also remember that the bottom of the :A:

board looked good too: It had no visible scratches--like the bottom of that SEGA ALTERED BEASTS PCB we briefly looked at awhile back.

As I recall, that SEGA PCB had a a graphics problem, booted fine, passed all the on board RAM test, and had visible scratches on the bottom of the SEGA " :A:

" board. I never got to finish testing the bottom of that board because the seller got it back. But, forum opinions were leaning towards a faulty graphics RAM chip on the " :A:

" board somewhere.

-----

I don't know why, but I usually read about CPS1 owners messing around with the :C:

board--bad battery, bad sound, bad background graphics, wrong music, dead board, etc.

Seems like that little :C:

board can cause a lot of things to go wrong on a CPS1. :angry:

Futasan · Feb 7, 2011

Can you give the location of the graphics ram, plz?
i have those types of corruptions, but i cant find any info about the locations of those rams...

thks

Futasan · Feb 7, 2011

can somebody tell the location of those rams?

Tyranix95 · Feb 7, 2011

I think so.

IMHO, some real :cool:

people use these forums. :glee:

CAPCOM Final Fight (US) PCB: Top: http://img57.imageshack.us/img57/6048/ffus9ix.jpg (Good pic.); Top & Bottom: http://www.emuparadise.org/MAME/pcb/ffight.png (Ok pic.)
CAPCOM :A:

Board (from a MAGIC SWORD): http://arcade.ym2149.com/pcb/capcom/msword_cps1mobo_pcb_partside.jpg (Hi-Res pic.)
CAPCOM :C:

Board (from a MAGIC SWORD): http://arcade.ym2149.com/pcb/capcom/msword_c_pcb_partside.jpg (Hi-Res pic.)

-----

On the a SEGA board, Womble pointed out SRAMs at F2, F3, F4 or F5 (aka G2, G3, G4, or G5) on the system board, and
Xian Xi pointed out Roms A14-16 and B1-8 on the rom board.

http://www.neo-geo.com/forums/showthread.php?t=217258

Kyuusaku · Feb 9, 2011

C.P.S.-A-01 on the A board is the VDP, C.P.S.-B-## on the C board is a peripheral graphics chip that can be thought of as an extension to the VDP. According to http://www.arcadecollecting.com/info/cps-b_numbers.html Final Fight should have a C.P.S.-B-04. If it doesn't, that would cause graphics corruption, but probably not vertical lines.

Vertical lines would be caused by broken traces on the B board (or connections to the A board VDP), but since only text is affected the traces would have to only lead to whichever ROMs the 8x8 layer is decoded to, which is suspicious. The PLD chip(s) on the B board are responsible for the decoding, so I guess if those malfunctioned you could end up with wrong tiles, but not vertical lines.

It's important to make the distinction between strictly lines, or wrong tiles as shown in the KOTR auction board. With vertical lines then data lines should be checked out (and possibly the C.P.S.-A s & B since data passes through them), but with wrong tiles only address lines and the PLDs need to be checked out.

When you say game character graphics are rendered incomplete, that sounds like a C.P.S.-B thing to me. Really you should take some pictures, it would make things much clearer.

Tyranix95 · Feb 9, 2011

Yes, Futasan, please post some pictures of your graphics corruptions.

We want to see the squiggly lines and the character sprites.

I don't have any pictures these--yet.

Thank you.

channelmaniac · Feb 9, 2011

Kyuusaku said:
C.P.S.-A-01 on the A board is the VDP, C.P.S.-B-## on the C board is a peripheral graphics chip that can be thought of as an extension to the VDP. According to http://www.arcadecollecting.com/info/cps-b_numbers.html Final Fight should have a C.P.S.-B-04. If it doesn't, that would cause graphics corruption, but probably not vertical lines.

Vertical lines would be caused by broken traces on the B board (or connections to the A board VDP), but since only text is affected the traces would have to only lead to whichever ROMs the 8x8 layer is decoded to, which is suspicious. The PLD chip(s) on the B board are responsible for the decoding, so I guess if those malfunctioned you could end up with wrong tiles, but not vertical lines.

It's important to make the distinction between strictly lines, or wrong tiles as shown in the KOTR auction board. With vertical lines then data lines should be checked out (and possibly the C.P.S.-A s & B since data passes through them), but with wrong tiles only address lines and the PLDs need to be checked out.

When you say game character graphics are rendered incomplete, that sounds like a C.P.S.-B thing to me. Really you should take some pictures, it would make things much clearer.

Vertical lines can be caused by bad solder joints on the surface mount chip on the C board as well as a bad chip there too... Oh, and scratched/gouged traces on it or bent pins where it plugs in to the B board too.

Bottom line: The CPS-1 boardset is a PITA to troubleshoot. You really need to have a good boardset that you can swap pieces around to figure out where the problem is. Even then it doesn't always tell you. The boards use different memory depending on the game so you can take a bad A board, swap it with a different game and come out with 2 completely working games. This is why I say you can't believe it when the board boots and shows the memory as good.

I hate CPS-1 systems.

RJ

Kyuusaku · Feb 10, 2011

Futasan said:
Can you give the location of the graphics ram, plz?
i have those types of corruptions, but i cant find any info about the locations of those rams...

thks

The 6x 62256 chips grouped together are VRAM but so is the huge array of HM53461/MB81461 chips which probably buffer the display.

Futasan · Feb 10, 2011

Tyranix95 said:
Yes, Futasan, please post some pictures of your graphics corruptions.

We want to see the squiggly lines and the character sprites.

I don't have any pictures these--yet.

Thank you.

Unfortunately, i sold the board a few days ago.
He swapped the A-Boards (with a short one), and the game runs fine now.

Tyranix95 · Feb 10, 2011

Sounds like an :A:

board problem.

Darn, I wanted to see a pic. of those lines and of those character sprites.

SpaceMX · Jan 9, 2018

Capcom CPS1 - Final Fight - graphic problem

I have a CPS1 - Final Fight PCB with a similar problem. Any idea how to fix it. Thanks in advance.

CAPCOM CPS1: Squiggly Lines.

Tyranix95

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jew90

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Xian Xi

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Hewitson

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