I'm looking for some assistance troubleshooting the left slingshot coil on my Bally Lost World. When the game is powered on, the slingshot works fine. After a few minutes of play, maybe 10-15 minutes, the slingshot gets progressively weaker until it doesn't work at all. The switches on both sides of the kicker work, sound and score, but the kicker doesn't kick. I assumed that the coil was bad and replaced it with a new correct coil/diode assembly, but the problem persists. The kicker moves freely and is not stuck when the coil quits firing. The next time the game is turned on, the cycle repeats.
Correct me if I am wrong, but don't the switches send a signal to the MPU, which sends a signal to the Solenoid Driver Board, which fires the coil?
Any recommendations as to what to check next?