FIXED:Cps2- a board missing backround colour

PCB problems and fixes
Hrvat9
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FIXED:Cps2- a board missing backround colour

Post by Hrvat9 » June 10th, 2017, 2:54 am

I got a xmen vs street fighter that just got the b board repaired with a new battery and I had a picture sent to me of it boot up; all was good. I just received it in the mail but to no avail (first connected it with the shellcase on, then without it) I can't get it to boot, only white screen. I've read that this means they arnt seated properly or something of the sort. There aren't any bent pins on the connectors. Any one know what's going on? Bad a board? I don't have another a board to try ...


Also , when I turn the game on, my NAC counter and the counter on the cps2 shell goes up by 12 everytime theyre powered on together. My NAC doesn't do that with any other game
Last edited by Hrvat9 on July 21st, 2017, 11:08 pm, edited 2 times in total.
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Re: Cps2 white screen

Post by Hrvat9 » June 10th, 2017, 4:04 am

Well when you're a noob to something new you're a noob! started cleaning everything possible on the a board and it came to life ! Missing colours though on characters and background but I'm sure some more cleaning will fix this
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Re: Cps2 white screen

Post by skate323k137 » June 10th, 2017, 4:34 am

Make sure your voltages are good at the jamma edge. CPS2 is power hungry, lots of chips to feed.

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leonardoliveira
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Re: Cps2 white screen

Post by leonardoliveira » June 10th, 2017, 9:06 am

The video output suggests that one of the graphics roms is damaged.

Check the roms numbered 13 to 20 on the B board. Those hold the graphics. Check for rusty pins, faulty pins on the sockets and if you can, try to read the 13-20 chips on a chip programmer and verify each dump against the mame rom for Xmen vs Street fighter.

Explanation:
CPS2 use 64bit graphics data (interleaved), which means it reads four graphics chips at once. Odd numbered chips (13, 15, 17 and 19) are read as 1st bank and even numbered chips (14, 16, 18 and 20) are read as 2nd bank. The board can also read 32bits, when reading on 32 bits (32bits reads are for CPS1 style background scroll and 64bit reads are for sprites) chip banks are 13-15, 17-19, 14-16 and 18-20.
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Re: Cps2 white screen

Post by Hrvat9 » June 11th, 2017, 10:53 pm

leonardoliveira wrote:The video output suggests that one of the graphics roms is damaged.

Check the roms numbered 13 to 20 on the B board. Those hold the graphics. Check for rusty pins, faulty pins on the sockets and if you can, try to read the 13-20 chips on a chip programmer and verify each dump against the mame rom for Xmen vs Street fighter.

Explanation:
CPS2 use 64bit graphics data (interleaved), which means it reads four graphics chips at once. Odd numbered chips (13, 15, 17 and 19) are read as 1st bank and even numbered chips (14, 16, 18 and 20) are read as 2nd bank. The board can also read 32bits, when reading on 32 bits (32bits reads are for CPS1 style background scroll and 64bit reads are for sprites) chip banks are 13-15, 17-19, 14-16 and 18-20.
Will do! I have yet to clean the rest ( a+ b board) ill post results when I do !
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Re: Cps2 white screen

Post by Hrvat9 » July 4th, 2017, 9:03 pm

Used Dish soap and the hose outside on the a board , got it all dried up and tried it out, white screen. Took the case off, white screen. I was puzzled so I tried not squishing the a board and b board so tightly together and it turns on. More than half of the glitches are gone in the background, now it's just the first player characters that are still missing colours. Going to clean the b board chips now
For reference , there's the 3 same pics as above after the a board was cleaned
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Re: Cps2 white screen

Post by Hrvat9 » July 5th, 2017, 12:32 am

leonardoliveira wrote:The video output suggests that one of the graphics roms is damaged.

Check the roms numbered 13 to 20 on the B board. Those hold the graphics. Check for rusty pins, faulty pins on the sockets and if you can, try to read the 13-20 chips on a chip programmer and verify each dump against the mame rom for Xmen vs Street fighter.

Explanation:
CPS2 use 64bit graphics data (interleaved), which means it reads four graphics chips at once. Odd numbered chips (13, 15, 17 and 19) are read as 1st bank and even numbered chips (14, 16, 18 and 20) are read as 2nd bank. The board can also read 32bits, when reading on 32 bits (32bits reads are for CPS1 style background scroll and 64bit reads are for sprites) chip banks are 13-15, 17-19, 14-16 and 18-20.
I cleaned every rom on the b board , some had some black spot on the pins , cleaned them till they were gone but I still have the same problem as noted above
Can you pull apart the connectors on the a board?
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Re: Cps2 white screen

Post by leonardoliveira » July 5th, 2017, 4:00 am

There might be faulty roms or cut traces. It's obvious what is happening is lack of graphics data. There are two banks of video ROMs on a CPS2 each bank is read on 2 chips at once for backgrounds (CPS1 style) or 4 chips at once for sprites. In the case of the big characters showing at the front, are sprites. So it's likely just one of the eight graphics roms are having issues.

Roms 13 thru 20 are graphics data.
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Re: Cps2 white screen

Post by Hrvat9 » July 5th, 2017, 4:52 pm

leonardoliveira wrote:There might be faulty roms or cut traces. It's obvious what is happening is lack of graphics data. There are two banks of video ROMs on a CPS2 each bank is read on 2 chips at once for backgrounds (CPS1 style) or 4 chips at once for sprites. In the case of the big characters showing at the front, are sprites. So it's likely just one of the eight graphics roms are having issues.

Roms 13 thru 20 are graphics data.
Could I desolder the battery and take out all the roms and clean the board with dish soap and water also?
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Re: Cps2 white screen

Post by leonardoliveira » July 5th, 2017, 4:55 pm

You could, but you will need the arduino to put keys back on after.

I can see the A board did indeed benefit from the washing.
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Re: Cps2 white screen

Post by Hrvat9 » July 7th, 2017, 12:55 am

leonardoliveira wrote:You could, but you will need the arduino to put keys back on after.

I can see the A board did indeed benefit from the washing.
Ah which I don't have, I just paid to get this b board fixed too. -_-
I'm thinking I pull out the roms and clean everything while masking off the battery somehow from water
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Re: Cps2 white screen

Post by nem » July 7th, 2017, 3:32 pm

Hrvat9 wrote:I'm thinking I pull out the roms and clean everything while masking off the battery somehow from water
That's a terrible idea. Don't do it.

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Re: Cps2 white screen

Post by NoAffinity » July 7th, 2017, 4:03 pm

I get similar issues from a known fault A board. Have tested that A board with multiple B boards, and its minor character graphic corruption just like what's seen in the most recent pics.

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Re: Cps2 white screen

Post by Hrvat9 » July 8th, 2017, 12:15 am

nem wrote:
Hrvat9 wrote:I'm thinking I pull out the roms and clean everything while masking off the battery somehow from water
That's a terrible idea. Don't do it.
I swear I'll be careful! lol no I looked at the b board for a second and my brain said "do not". So I didn't :awe:
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Re: Cps2 white screen

Post by Hrvat9 » July 8th, 2017, 12:15 am

NoAffinity wrote:I get similar issues from a known fault A board. Have tested that A board with multiple B boards, and its minor character graphic corruption just like what's seen in the most recent pics.
I got another a board coming with a progear I just bought so we'll see what happens when I get it
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Re: Cps2 white screen

Post by leonardoliveira » July 9th, 2017, 5:41 am

Hrvat9 wrote:
leonardoliveira wrote:You could, but you will need the arduino to put keys back on after.

I can see the A board did indeed benefit from the washing.
Ah which I don't have, I just paid to get this b board fixed too. -_-
I'm thinking I pull out the roms and clean everything while masking off the battery somehow from water
Electricity doesn't work that way. Power run through all custom ICs on the board, even though only the DL-1525 need power for keeping the keys. Water and soap will react with the electicity causing rust to form. Also the battery will be drained off.
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Re: Cps2- a board missing backround colour

Post by Hrvat9 » July 16th, 2017, 3:02 am

I just plugged in a progear b board onto the a board that came with xmen vs street and it does the same thing, no backround colours/black and white backround so it has to be the a board.
Xmen vs street works beautifully on the a board that came with progear
Where do i look on the a board now ? Id assume its hard to probe the a board chips with a b board on top...
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Re: Cps2- a board missing backround colour

Post by leonardoliveira » July 21st, 2017, 12:11 am

Likely you have a faulty CPS-B-21 chip (same chip as CPS1, but on CPS2 the object stuff on the B chip goes unused) which does handle the scroll layers. Sprites are perfect, right? Sprites are handled separately by the SPB chip and surrounding stuff (including a 1MB of EDO RAM buffer in the form of two 512KB 16bit DRAM chips).
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Re: Cps2- a board missing backround colour

Post by Hrvat9 » July 21st, 2017, 2:48 am

Yeah sprites are good, but when they blow up they go black and white like the backround. Ill take a picture and post it now
leonardoliveira wrote:Likely you have a faulty CPS-B-21 chip (same chip as CPS1, but on CPS2 the object stuff on the B chip goes unused) which does handle the scroll layers. Sprites are perfect, right? Sprites are handled separately by the SPB chip and surrounding stuff (including a 1MB of EDO RAM buffer in the form of two 512KB 16bit DRAM chips).
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Re: Cps2- a board missing backround colour

Post by Hrvat9 » July 21st, 2017, 10:58 pm

Get a load of this! Im sitting and watching the game play and i said ok whatever i guess i have a screwy a board and i go to pick it up from the back of the two pcbs. I put my hand in between them and i mustt have touched a chip in there because the screen started to flicker like crazy. Hm so i investigate and there was only three chips that i could have touched, three 74ls157 small chips right above the cps-b-21 chip and i noticed one pin was just a slight bit dirty. I sort of scratched it with an exacto knife and threw some solder on it quickly and voila!!! A board is running mint !! :D 8-) 8-) 8-)
Super lucky and super happy i got it going perfect.
Whats a good site to upload pics now?
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