CPS1 graphical issues horizontal lines

[Notsuoh]

Hi,
I was wondering if anyone has had an issue like this on their CPS1.
I'm experiencing horizontal lines and out of place flickering graphics, seems to related to a sprite or tile layer.
I have flex tested the PCB with no help.
There are no visible hardware damages, or I would not be asking, lol.
I have tested with another CPS1 final fight board and can confirm my B and C boards are fault free and that the problem is the series 7 CPS1 A board.
I suspect a bad flip-flop or ram, but I'm not sure what area is what on the A board.
Please look at the photos of the problem I'm experiencing.
This is the only problem, everything else is working as it should.
Thank you for you interest and time.
Stay safe and well.

 

[Apocalypse]

If you're lucky bad DRAM.
Otherwise bad CPS-A-01 custom chip.

 

[Notsuoh]

If you're lucky bad DRAM.
Otherwise bad CPS-A-01 custom chip.

Where is the DRAM on the A board?
Thanks.

 

[djsheep]

Here's a repair log that might help:

https://www.jammarcade.net/capcom-cps1-street-fighter-2-ce-repair-log/

 

[Notsuoh]

Here's a repair log that might help:

https://www.jammarcade.net/capcom-cps1-street-fighter-2-ce-repair-log/

Thank you, I will now investigate further.
Stay safe and well.

 

[Notsuoh]

Here's a repair log that might help:

https://www.jammarcade.net/capcom-cps1-street-fighter-2-ce-repair-log/

Thank you, I will now investigate further.Stay safe and well.

I have actually read that and watched the video previously, if I get no issues in the self diagnosis related to the work ram, could there still be a problem with the work ram?

 

[Apocalypse]

I have actually read that and watched the video previously, if I get no issues in the self diagnosis related to the work ram, could there still be a problem with the work ram?

There are several banks of RAMs.
If work RAMs were bad game wouldn't boot or would have bugs. Self test doesn't test DRAMs used for graphics.

 

[Notsuoh]

I have actually read that and watched the video previously, if I get no issues in the self diagnosis related to the work ram, could there still be a problem with the work ram?

There are several banks of RAMs.If work RAMs were bad game wouldn't boot or would have bugs. Self test doesn't test DRAMs used for graphics.

Hi,
Thanks for your input.
Where are the DRAMs on the A board?
Thank you.

 

[Apocalypse]

With JAMMA edge facing down they are in the upper left corner. 12 chips (some boards have 16 but 4 are unused).

 

[Notsuoh]

With JAMMA edge facing down they are in the upper left corner. 12 chips (some boards have 16 but 4 are unused).

Thank you Apocalypse, I will probe them and see if I can't find an issue.
I have not been able to find any similar photos of these graphical glitches online, so maybe I will be lucky and just have a bad DRAM.
The PCB is in as new condition with the cleanest gold finger I have ever seen.
So fingers crossed mate.
Stay safe and well, thank you.