Quoted from pindergast:OK well if that's the case then it's something in addition to optos on TZ. So when the PinLED is installed on TZ, I get:
1. All of column 2 lights up when the coin door is closed
2. Clock 0 minutes (92) is stuck on
3. The auto-fire kicker constantly runs (while empty); that opto appears to be stuck on
Put the Williams board back in and all three symptoms go away.
So with that it's starting to look like both column2 and possibly row 2.
Okay -
Can you grab a pick of the Switch Test (T.1) with both boards in?
It's very possible that with the higher +12v, the old optos (phototransistors) are starting to fail - letting too much current through to latch the BA339 on the column.
For the coin door - is it the coin door closed switch, or the physical door itself?
If you *disconnect* the ribbon cable going to the power driver board, and go into T1 (Switch Test), what happens?
(*) I forgot to clarify myself in my first post: I have one issue with my PinLED PDB board - it amplifies the LED ghosting/flickering. I had to use very, very conservative settings in my LedOCD & GIOCD boards to get them looking great.