Making the start button add a credit

Steps

• Set at least one coin chute to 1 coin/1 credit, a normal replay level and the maximum credit limit.
• Remove the start button's leaf switch stack from the coin door (two screws).
• Add a spare two-blade leaf switch to the stack, removing spacers as needed, with fish paper between the switches and clear of the metal plate.
• Adjust it to close before the start switch.
• Wire the new switch in parallel with the coin switch set in step 1.
• If credits build up from replays and matches, turn those off on the DIP switches.

Systems

• Bally MPU AS-2518-17
• Bally MPU AS-2518-35
• Stern MPU-100
• Stern MPU-200

Related tips

• Adding a credit push button

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