A flash lamp does not light in the solenoid test.

Flash lamp dead on an early System 11 game

Cause: Bad bulb (or its partner if two are wired in series), poor connections or an open resistor on the playfield resistor board.

Checks

• Test the flash lamp in the solenoid test and troubleshoot it like a coil.
• If two flashers are wired in series, check both bulbs.
• On early games, check the resistor board: R2 5 ohm 10 W current limiter and R1 330 ohm 7 W filament pre-heat.

Fix

• Replace the bulb, resolder connections or replace the open resistor.

Systems

• Williams System 11
• Williams System 11A
• Williams System 11B
• Williams System 11C

Related tips

• Dim GI and backbox lamps: GI relays swapped for boards that were miswired
• LED GI goes dim during play: poor header on the interconnect board
• Rebuilding a burnt J6 GI connector: striped wires on the first four pins
• Where the flash lamp resistors are by era
• System 11 backbox boards and supplies
• Banzai Run: interconnect board flash resistors
• Lamps under the slingshots out: wire in the wrong position in interconnect plug J12
• Flashers dead on Banzai Run and later: interconnect board resistors

Source: Pinball Machines: How They Work & Troubleshooting, Norbert Snicer