OP

Quoted from jasonbar:

Thanks for the feedback.
Found I had 1 MOSFET from a previous machine. Got ready to pull the board & swap the MOSFET. Wanted to do 1 final test to double-check that I had the right component targeted before I dove in.
Plugged the J108 connector back into the PCB. Powered up, tested coils. ALL WORKED! The only thing that I changed was disconnecting & reconnecting that connector. I looked in at the pins in the harness Molex connector. Pin 7, Munchkinland Flipper Hold, was rather bent & might not have been making good contact w/ the PCB header, so I removed it, bent it, & re-inserted it, but that wasn't the problematic coil anyway... :\
Mixed feelings. Glad it's working, but suspicious of self-fixing. Played a few games (w/ my 4A fuse still in there). Played fine.
2 items of note:
- I found a 250V 6.3A fuse, unblown, next to the I/O PCB. I don't know if it's possible that it was under the I/O PCB & shorting the right sling pin--it was in the same general vicinity..
- Right sling seems to double-activate. Other slings just go "bang!", while the right sling goes "ba-bang!"; it has a slight rattle/rebound/double-activation. It seems to play fine, though. Perhaps a nit-pick, perhaps a clue or culprit?
Thanks,
-Jason