Ok, so I had the playfield out to work on the ramp diverter and relocate the stoplight, and it's good news, bad news. I figured out why the diverter kept sticking, a C-clamp had come off and was letting the bat slide further up than it should, which was causing it to get caught on the ramp. The stoplight looks great in the back left of the cabinet, and I don't have to worry about an airball knocking the case off any longer.
Unfortunately, now I've got a bunch of stuff that won't respond. The wiring didn't get kinked or squashed during the process, I was very careful about that. GI and flippers work in diagnostic modes, but a few switches seem to be affected, since the ball trough doesn't register (this causes the game to fire all coils to try and dislodge the ball, but the saucer is the only one that actually goes). I did run through the edge and switch tests, but IIRC, almost all of them worked. None of the coils/flashers affected share a transistor, am I right to be looking at the big plastic playfield connectors first? Until now, I had never disconnected any of them, and I'm wondering if they're not making good contact. I've tried reseating all connectors in the backbox and to the playfield to no avail. Everything was working great before this, and I feel like once I get this issue sorted and clean up the shooter lane, it'll be ready to bring in the house from the garage.
Thanks to the test mode, here's the list of what's not firing with their part numbers and corresponding transistor:
Outhole 1P11-1 8P3-1 Q33
Ball Release 1P11-3 8P3-2 Q25
Flasher 1 1P11-9 8P3-9 Q17
Flasher 2 1P11-6 8P3-5 Q31
Flasher 3 1P11-7 8P3-6 Q23
Left Hideout 1P11-8 8P3-7 Q30
Right Hideout 1P11-9 8P3-8 Q22
Ramp Gates 1P12-6 8P3-13 Q15
Kickback 1P12-7 8P3-14 Q7
Right kicker 1P19-4 8P3-18 Q71