I have this love/hate thing going on right now with my machines. I decided to pick up a Rottendogs PDB to have as a spare/temp board so I could take my time with other repairs as they come up. The original still works, but it needs a little TLC and some repining.
Anyway, I swap in the new RD PDB ... and notice I'm getting ghosting on other LEDs on the same row in the matrix. Ghosting may not be the right term, but in this context I'm meaning lamps that should be off are glowing slightly. For example, on my ToM, 56 (Start Illusion) lights fine, but then 66 Safe Escape ghosts. 66 causes 76 Illusions to ghost, and 76 causes 86 Shoot Again to ghost. This happens on every row -- 14 causes 24 to ghost, 24 causes 34, etc., but not necessarily every lamp. (The LEDs are Cointaker non-ghosting.)
Naturally I thought it was the RD board as I didn't recall seeing this before. I pull it, swap the original back in. Turns out the ghosting is still there, but much fainter and barely noticeable.
So, not sure if this is a short, a diode, or other issue. I've bookmarked a few pages that discuss lamp matrix troubleshooting, but because I'm seeing this across so much of the matrix, not quite sure where to start. Any tips?