Quoted from barakandl:
I missed that. The original video does still look like the exact symptom of blown PF fuse causing the MPU to endlessly try to clear the outhole, yet cant.
You can send me back the MPU and/or driver and I can check / repair. Maybe a switch's PIA port crapped out.
However maybe he NEEDS to put the ball in as well? Clearly there's an issue (a real, different one) but I'm saying that also perhaps the ball does need to be in the outlane - so once you fix something else and it could be working again, remember to do testing with the ball in the machine. Then it could be a transistor for the coil, the coil, or anything, it opens up a bunch more opportunities/possibilities.
I was working on a customer's Centaur and I don't think it would start correctly until the last ball was in the trough, if I'm not mistaken. Not sure how this translates over to Stern games.