The same one or two flasher bulbs fail far more often than the others.

One flasher keeps burning out

Cause: More than 20 V reaches that bulb because one of its wires touches another supply; otherwise a leaky TIP102.

Checks

• Measure from the flasher socket to ground; anything well over 20 V points to a wiring short.

Fix

• Find and separate the touching wires; if the voltage is right, replace the TIP102.

Systems

• WPC Alpha-Numeric
• WPC Dot Matrix
• WPC Fliptronics
• WPC DCS
• WPC-Security (WPC-S)
• WPC-95

Related tips

• Flasher over the upper right flipper melts its plastic: the flasher is stuck on
• A flasher lights up whenever other coils fire: try an incandescent bulb
• Flasher glows full bright until the bulb blows: shorted driver transistor
• Most flashers only flicker faintly: broken wire on a playfield bus strip
• No flashers in game or test, and coils won't fire in test: bulbs and coin door interlock
• One flasher never lights

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