Game Plan Sharpshooter (Game Plan, 1979) Bumpers not working

[dblanch]

I just got a sharpshoot machine by game plan and all the upper bumpers aren't working. Noticed they were all wired in parallel so I traced the wires to the harness and found that the path hits a dead end. The yellow black wire has nothing on the other side and, what I can find in the wiring diagram (I'm a total beginner at wiring) it is supposed to be connected to 15VDC from the power supply. The problem is I can't find any loose wires in the cabinet. Can I just splice something together and wire somewhere else? https://drive.google.com/open?id=1kSeV5pKqnO8k_ezrHv0VpyMOoe9ZCUhP

 

[pinballdaveh]

The yellow-black wire is the daisy chain common wire that connects each coil on the playfield. Each coil is driven by a driver transistor on the driver board. Have you tried the self test function to see if the suspect coils actually work? Because it still might be a switch or board problem. If any of the playfield coils do work the yellow-black wire is working. Sometimes a wire will have a color change in a connector from the cabinet to the head.