A motor or relay never runs.

A motor or relay does not work

Cause: Fuse F103, its TIP102 driver, the wiring, or the device itself.

Checks

• Check F103.
• Check the TIP102 that drives it.
• Check the wires and the motor or relay.

Fix

• Replace the fuse, transistor or device.

Systems

• WPC Alpha-Numeric
• WPC Dot Matrix
• WPC Fliptronics
• WPC DCS
• WPC-Security (WPC-S)

Related tips

• One flasher never lights
• A coil does nothing although its fuse is good
• Auto-plunger coil energized as soon as the coin door closes: coil shorted to its bracket
• Launch coil locks on and blows its transistor and fuse every time it is tested
• Flasher over the upper right flipper melts its plastic: the flasher is stuck on
• Left mini-playfield magnet dead, about 8 V at it: F101 blows, shorted Q26
• WPC coils need no diode except the flippers
• Driver transistor dies after fitting a coil that has a diode

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