I have been working on a Chicago Cubs Triple Play (Gottlieb System 80B). I have gotten the game to boot. For a short time everything was working. However, now when I turn on the game it starts up and the drop targets reset (you can hear a hum). After a just a couple seconds, fuse F12 blows. F12 is for the drop targets. I have check each switch, coil, and diodes out of circuit) all tested OK. I pulled the mechanism and checked the coils on the bottom of the mechanism. Those also tested OK I replaced the diodes for these coils. I cannot find any shorts or loose wires and everything appears as it should. If I have the drop targets unplugged the game funs normally. I am not sure what to do next. Any suggestions on what I should check?

Hi Chris,

Thanks you for the reply. I'll check it out.

Update: Chris your the man! With you pointing me to a transistor, with my limited ability, I was able to trace path on schematics back to the transistor (Q62) on the driver board. Pulled the board and test the transistor comparing it to another one. Sure enough it read back. I replaced it and now have functioning drop targets. Learning has occurred. Thanks again without your input figuring this out on my own would have taken me much much more time.

Regards,
Phil