My son in law's game has started doing odd things (again), in that it is not seeing the balls in the trough. I'm assuming a problem with the opto receiver board as it looks like all the optos are lit on the emitter, however at the same time this appeared the flippers also are not responding and if a ball is placed in the shooter lane it will not launch. That switch is clicking if manually operated. It thinks it has started a game, but as a ball is not launched it should start looking for a stuck ball, but doesn't. All that happens is that the cryo claw swings back and forth, then repeats. Not sure where to look other than replace the receiver board. Any suggestions gratefully received, as I'm only at their place until Monday next week and hope to get sorted before we leave. Cheers, Graham