If the fuse was bad all the switches in trough would be out.
Quoted from Neal_W:If your worried about the trough, start with the switch test. Remove all the balls and add the balls 1 at a time. Anything unusual with the switches seen? If you knock on the playfield or flip the flippers, do you see any changes with the trough switches during the above test of adding 1 ball at a time?
I can't imagine why a bad trough switch would eject balls after power up. I would start at the beginning. Measure the power supply test points. Any battery leakage seen?
I did switch test, all switches seem fine. Was playing closest attention to the ball jam opto and that also seemed ok…although it did flash quickly every time a ball came through but did not stay open.
Thinking it could be a bad diode in the trough or a short on some other switch causing it to go haywire. Will do the bang test tomorrow