When I turn the game on with all of the plugs pulled from the magnets that fuse doesn't blow. If I turn the game off and plug one of the magnets in it blows when it boots up. With a good fuse and all the magnets unplugged I'm getting 72 volts coming from each magnet plug with the game in attract mode. Optos work fine all new transistors (9) on the accelerator board. Is it time to replace U2 and U3?