Just finished cleaning up an Apollo, was very excited about this one because it is a keeper. However, when I got it there were numerous scoring problems, and it was really dirty. Got the scoring problems solved, did the typical tear down to clean and polish everything, replace the bad lamps and fix the bad sockets.
When I first put it back together, it would start a game fine. Then during play, when a ball drained it would randomly fire the kick out coil over about 3 to 6 times, and skip a ball, sometimes two. ie: after first ball, would jump to second then third ball, or after fourth ball would stop on five then go to game over. but the kickout fired more often than the stepper skipped balls. After the diagnosis attempts noted below and checking the entire outhole switch / relay circuit (yes I have a schematic) it now does it after every ball. Progress of a sort. Diagnosing attempts to date:
Traced every wire in the ball return / kickout sequence. Can't find a short or break. (Which of course doesn't mean there isn't one)
Cleaned and gapped and visually checked that the movement was correct, on every switch in the circuit, including on the score motor.
Checked the small ball kicker switches / gaps.
Unscrewed the score motor from the bottom board and visually inspected, checked gaps, and cleaned contacts. In particular on stack 4.
Checked switches and gaps on every relay in the circuit, in particular the Outhole relay.
De-soldered outhole switch, and touched wires directly to fire the outhole relay / kicker.
With outhole kicking over and over, opened / closed manually every relay in the game, and moved by manually pushing coil rod - every stepper in the game. And nothing made it stop. It either eventually stopped on its own, the ball count finally kicked to game over, or I turned the game off.
Odd notes: Took the kickout switch out because it showed continuity on the meter whether contacts engaged or not, testing at the solder lugs. After switch removal, wires were still showing continuity through several simulated ball return cycles - then all of a sudden while connected to the meter - stopped showing continuity and wouldn't fire the outhole relay. Nothing, dead. I still could fire the outhole relay with the switch contacts on the relay itself - and then it still repeats over and over.
Feel like I am missing something simple and stupid to miss. Ideas?