The score motor keeps running.

EM score motor will not stop

Cause: Most often a shorted (stuck closed) switch elsewhere in the game, rather than on the motor.

Checks

• Check playfield switches, switches on solenoids, targets, the outhole and kickout holes for any held closed.
• See whether every score reel returned to zero.

Fix

• Re-gap the stuck switch.
• If a reel is not at zero, see the score reel entry.

Systems

• Electro-mechanical

Related tips

• What the score motor does
• A score motor that won't stop is rarely the motor's fault
• How the score motor resets the reels
• Check the score motor switches before power-up
• Score motor keeps running at game over, O relay stays in: score motor 2C switch
• 1970s Chicago Coin: motor runs on at reset
• Players 3 and 4 reset but players 1 and 2 never do at game start
• Score motor keeps running after start is pressed

Source: Pinball Machine Care & Maintenance, Bernard B. Kamoroff (Bell Springs Pinball Alley)