I had the same thing happen to my Williams Getaway HP2, mine would re set if the balls where in the supercharger and both flippers energized.
Wiggled the J10 connector on the driver board (top right) and that fixed it for a time but it came back.
I had the pins replace at J10 and one of the big black caps replaced and the problem went away.
it will be a connector problem or a faulty 5 volt reg
