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CPS2 weird graphics issue

arcadeqc

arcadeqc

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I am experiencing issues with this CPS2 A board's video output. The colors are garbled, but the graphics are visible. Is this likely to be an issue with one of the customs ICs, or is there something else I should look into?

cps2_problem.png
 

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Try replace the LS157 (7U,7V,7W) between DL-0921 and DL-1625. I recommend start by 7W. Pay attention for bad traces around it too.
 
Ok, I will look into replacing those, thanks for the tip. Am I right ordering them in package 16-SOIC? Visual inspection of the board is good, I rechecked in that area specifically and it is in good shape overall. Something interesting I found is the color test in the service menu. Seems to affect Red and Blue channels mainly.

cps2_color.png
 
you sure the B board is seated properly?

I had a B board I chased a problem down on for days...turns out the screws holding the plastic together were stripped, and the plastic wasn't allowing for a proper seated connection. Fixed that issue and all my graphical issues went away.

Just something easy to try before dealing with components :)
 
I removed the B board from the plastic shell to make sure I can properly seat it, they are firmly coupled.
 
It’s funny how tightly connected a B board can seem, even with the metal clips, and somehow when you go bare pcb it magically works. I think whatever plastic Capcom used warps over time due to age and Heat
 
I’m not sure if this was clear from my post. Even though I removed them from their plastic casings and firmly connected them, the issue is still there.

I have removed the 3 LS157s between the DL-0921 and DL-1625 and cleaned the pads. All the traces look clean and I am waiting for replacements from Digikey this week.

I first tried simply reflowing them, but it didn’t change the output.

C9FE08FD-1BF7-4063-82D6-74D255C0AF61.jpeg
 
@arcadeqc you think the LS157 could be causing my issue as well? my reds look about the same as yours. Also I have a green or blue filter that covers the image depending on what is displayed.
 

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Give it a try. Pay attention on Jamma RGB pins, sometimes the traces around there break over the years.
 
Can you go into the service menu and look at the color bars? As you can see in my initial post, the blue channel was totally screwed up, no only faded. Your screen looks more like a color imbalance. Maybe some resistance or capacitance somewhere needs to be replaced?
 
After some more digging, I found that when mounting the CPS I/O, I broke the solder to the pins that attach it to the top of the chips on which it sits. reflowing made it work perfect. Thank you for your answers.
 
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