Did you ever find a fix on this? I have the same thing happening with one of my asteroids boards. Images are doubled and test switch makes screen go blank. I get three tones with the test switch on then nothing.
EDIT: doh! manual says I have a failing M4 RAM as the 3rd tone is lower than the others
I'll go ahead and replace the known faulty ram (which under visual inspection actually looks like it is damaged) and go from there. If I hit a roadblock, I'll shoot road.runner a msg