Just a quick fix for a Shadow Warriors PCB I had since many years but never looked at:
Gameplay was fine but all the backgrounds GFX were scrambled and messy:
This is the part of circuit which generates the backgrounds, located on video board:
Luckily EPROMs and RAMs were socketed so I first tested the latter and found a bad one @3D (a Toshiba T5563 pin to pin compatible to a generic 6264) :
Replacing the bad chip was enough to clear the issue.