A score relay, reel and chime stay energised as soon as the game is on and start to overheat.

Old rubber holding a playfield switch closed

Cause: Old, hardened playfield rubber is pressing a playfield switch shut.

Checks

• Inspect every topside playfield switch for a ring pushing on it.

Fix

• Replace the rubber and re-gap the switch if needed.

Systems

• Electro-mechanical

Related tips

• Cleaning lightly soiled playfield rubber

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