Usually people post about score reels not resetting... my problem is that I’ve seen a few cases of the score resetting to zero in the middle of a game

I haven’t seen it enough times to identify a pattern. It is definitely while the ball is still in play - not when it hits the outhole. Since it takes several pulses, the score motor is involved. It’s not a full reset, because the ball count stays put. It takes many games to get this to happen, so it’s tough to reproduce.

Admittedly, I need to stare at the schematic some more, but I figured I would post in case someone had any pointers.

Thanks!

Thank you both for the pointers. I did check out the A relay. The switches look OK in both the latched and unlatched positions. I did notice that if I trigger it by hand it caused exactly the behavior that I have observed. I also noticed that there was a good amount of crud on the knife edge that performs the latch and unlatch operations, so I cleaned that all up. I also adjusted the 2B score motor switch to make sure the A reset pulls as long as it can to get into the running position. My theory is that the relay was just barely in the reset-done state and vibration allowed the latch to slip and start a score reset sequence. We’ll see if it happens again.

Hasn’t come back, so I’m marking this one as fixed. Time will tell