Quoted from pinballrebel:Fuses check fine. Coil works in test. Wiring is good from board to opto. Could it be a fault on the fliptronics board? I've never had that happen.
Ken
Yes, it's a simple 4-channel opto-isolator. If something happened on that one circuit (high voltage pulse, for example), the opto-isolator could be blown for that channel.
But since a new fliptronics board - or fixing the existing one - is time-consuming and expensive, that's why you check everything else.