Playfield lamps go out, coils are weak or intermittent, or fuses blow.

Loose wires on the backbox bridge rectifiers

Cause: Loose push-on lugs on the two backbox bridges.

Checks

• Wiggle and inspect the wires on 6BR1 and 6BR2.

Fix

• Squeeze the lugs tight with pliers and reseat them, or solder the wires to the terminals.

Line voltage is present in the cabinet; unplug the game before working on it.

Systems

• Williams System 3
• Williams System 4
• Williams System 6 / 6A
• Williams System 7

Related tips

• Backbox bridge rectifiers and their wires
• Test a bridge rectifier with a meter
• Flippers too weak for the top lock: loose, arcing bridge rectifier connections
• The backbox bridges and can capacitor are not logic power

Source: Repairing Williams System 3 to System 7 Pinball 1977 to 1984, Part One, Clay Harrell (pinrepair.com)