Quoted from Mopar:
Perhaps the plate(s) are magnetized. The next
time it happens, go in back of the machine and see which Pin Relays
(in the Relay Bank) are in the tripped (energized position..
That was always a problem when I used to have bowling machines.
The little metal plate on the relay would get magnetized and trip the pins.
I used to put a piece of electrical tape on the back of the plate for a quick fix.