LED5 is out and flashers do not work.

Driver board LED5 off (+20 V flashers)

Cause: From Twilight Zone on, LED5 fades out by design when the coin door is open. Otherwise fuse F111, bridge BR4 or capacitor C11. Supply comes in on J102 pins 1-2 and 3-4 and leaves on J107 pins 5-6 (and J106, J108).

Checks

• Close the coin door and look again.
• Check F111 and measure TP7.

Fix

• Replace the fuse, bridge or capacitor.

Systems

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

Related tips

• Driver board LED5 off: flasher 20 V missing (WPC-S and earlier)
• WPC-89/WPC-S driver board LEDs and test points
• Driver board filter capacitors wear out
• Voltages made by the WPC power driver board
• Bridge rectifiers to use on WPC-S and earlier driver boards
• Supplies made on the WPC power driver board
• Driver board LED1 off (+12 V regulated missing)
• Driver board supply test points and normal readings

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