Credits are shown but pressing start does nothing.

Game boots with seven flashes but will not start even with credits

Cause: Worn or torn fish paper behind the start button grounding a whole switch strobe; also balls missing from the trough or a stuck tilt or slam switch.

Checks

• Inspect the start button's insulating paper.
• Check trough, tilt and slam switches in switch test.

Fix

• Replace the fish paper; free stuck switches or add the missing ball.

Systems

• Bally MPU AS-2518-17
• Bally MPU AS-2518-35

Related tips

• Self test will not start from the coin door button
• Player 1 display shows credits and ball in play

Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part Three, Clay Harrell (pinrepair.com)