Quoted from Tonup69:
Yes. I also blocked the switches, checked the gaps, cleaned them, looked for solder bombs and anything else I could think of doing - I'm at a loss. I was starting to consider unsoldering the orange/slate lead from each switch until the motor stops. It MUST be one of them, right?
Sometimes it helps to do a sanity check when you're at this point, even though it must be one (or more) of those switches based on the schematics. Have you verified that the wiring you have matches the schematics and number of switches? Also, how are all the orange/slate wires connected - daisy-chained from one switch to the next, and the final one leads to the score motor?
If you're to the point of desoldering for sanity checks, you might try disconnecting the final wire to the score motor first. If it's still running then you have something really screwy going on. If it stops, you can put it back and then disconnect half the switches in the chain. Then repeat eliminating half the switches until you find the one making the difference. If you've already tried blocking / opening all the switches simultaneously (not individually, in case more than one was closed), then perhaps this will help find a stack that is shorted near the screws.