The game starts and a fuse blows.

A fuse blows as soon as a game is started

Cause: A coil that is stuck on, a shorted bridge rectifier on a 1970s Williams or Bally, or a direct short in the wiring.

Checks

• Note which fuse it is: a GI fuse only kills the playfield or backbox lights and usually doesn't stop the game.
• Look for a coil plunger held in, and measure suspect coils (under about 2 ohms is shorted).
• On DC-kicker Williams (1972 on) and Bally (1976 on) games, test the bridge rectifier.

Fix

• Replace the shorted coil or bridge, and find the switch that held the coil on.

Systems

• Electro-mechanical

Related tips

• Solenoid fuse blows
• Finding why a fuse blows: start with which circuit
• Fuses to keep for EM games
• Where EM fuses are
• Test a fuse properly with a meter
• Check fuse ratings before the first power-up
• Gottlieb reset bank fuses
• Game won't start and score motor won't run: bad fuse clips on the 25 V fuse

Source: Repairing Electro-Mechanical (EM) Coin Operated Games to 1978, Part Two, Clay Harrell (pinrepair.com)