Demon Front stand alone PCB sprite color problem

[XtraSmiley]

Gents, I have a Demon Front PCB I'd like to fix up and sell/trade but when I went to test it, the sprites around the main figures and some words are the wrong colors. It comes and goes (pressing and/or twisting the board doesn't seem to affect it) with it being wrong more times than it is right.

I tried removing and re-inserting the EPROMs but that's about it. Anyone able to focus me on an area to look at. I don't have a probe (yet) and I'm not in a rush to fix it, but if this is common issues someone has seen before?

Then last picture is the color the sprites should be.

 

[kikaso]

@GC8TECH is the most knowledgeable person I know when it comes to PGM. He’s helped me out whenever I’ve had issues.

 

[Fluffy]

Hmmm... A-ROMs store a colour index, so my guess is that any error there would look more like random noise than wrong colours. Palette CRAM or DAC? No idea which chip that is on PGM, or if that is integrated into one of the ASIC.