Check GI routing before swapping transformers

Hot Tip, Lucky Seven and System 7 route GI power through the power supply board, while World Cup to Algar feed GI straight to a fuse card, and plug layouts differ. Firepower II, Laser Cue and Star Light transformers add a 48 VAC flipper winding, so older transformers do not work in those three. System 3-6 transformers are in the backbox; System 7 moved it to the lower cabinet.

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

Games

• Firepower II
• Laser Cue
• Lucky Seven
• Star Light

Related tips

• The 300 V circuit on Hot Tip and Lucky Seven supplies

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