To explain further, the glitch in the original program causes the trunk motor to hang up if there should be a signal from the eddy circuit while the motor is running. So, you hit the pickup 3 times during game play, setting the trunk in motion. Then another ball hits the pickup during the motor movement and the glitch does its thing.
A software programming modification would call out ignoring the eddy pickup signal during motor motion. Not gonna happen, so we need to do a hardware modification.
While I'm on the eddy circuit, the biggest problem with failure of the circuit is the poor connections on those flimsy connectors. If the sensor connector pins pick up corrosion (which they all do) or lose spring tension to the pins (which they all do), you're forever tweaking the trimpot to get the circuit to function normally.
Might as well mention the carbon trimpot too...they tend to get flaky and lose their setting. Easily replaced if you can solder down to PC board component level.
So one of the easy fixes for that two pin sensor connector is to cut it off, strip the wires, and then solder those two pins directly to the sensor wires. Connector is eliminated from the mix. You need to be very familiar with soldering techniques for tiny parts.
The other connector has the same issues, so you can solder directly, or replace that connector. You need the tools to replace those small AMP terminals, though. Hit the pins with a pencil eraser to clean up any corrosion on them. Temporary fix, but it does solve the eddy board issue without having to replace the board. The self-adjusting boards will get flaky too, if the connectors don't connect properly, so replacing the board doesn't always fix the actual problem.