None of the low-power coils work; the fuse is fine and power reaches the driver board but goes no further. The +20 V LED on the driver board is out.

WPC-95: all the 20 V coils dead, fuse good

Cause: A cracked solder pad on the filter capacitor after that supply's rectifier stops the DC getting past the rectifier. Seen on a Safe Cracker.

Checks

• Check whether the +20 V LED on the driver board is lit.
• Inspect the rectifier and filter capacitor solder joints for cracks.

Fix

• Solder jumper wires from the rectifier outputs to the filter capacitor, as is done for the 5 V bridge.

Systems

• WPC-95

Related tips

• WPC-95 driver board LEDs and test points
• Supplies made on the WPC power driver board
• Shorted or open bridge rectifiers
• WPC flashers and coils all dead? Check the coin door interlock first
• 12 V unregulated LED out on the driver board: open track to C8
• WPC-95 LED102, LED103, LED104 or LED105 off
• Adding backup jumpers to a WPC-95 driver board
• Check fuses F106/F101 with no lamps and no game start: shorted bridge diode

Source: Repairing Williams/Bally WPC Pinball Games from 1990 to 1999, Part Two, Clay Harrell (pinrepair.com)