It's been awhile since I had this game (~20 years) so my memory isn't perfect. When mine had this issue, it turned out to be an issue with the opto boards in the trough. The LED board has black and red (I think) power wires that run up to the CPU board for power. Check to see what voltage you get, and check to see if the IR LEDs are working. If the game is constantly trying to kick out all the balls, it is doing it because the game thinks the balls are still in the trough which is why I think it is the an opto problem. When the game realizes the trough isn't clearing, it assumes(incorrectly) that the eject coil is bad, which is why it tells you to check the solenoid fuses. I hope that helps!