Score display digit parts by position

Ones: R1, level shifter Q1, driver Q7. Tens: R3, Q2, Q8. Hundreds: R5, Q3, Q9. Thousands: R7, Q4, Q10. Ten-thousands: R9, Q5, Q11. Hundred-thousands: R11, Q6, Q12 (page 58). On 7-digit boards the millions digit uses R56 with level shifter Q20 and driver Q21. Segment drivers a-g are Q13-Q19 in order.

Systems

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

Related tips

• Flickering score displays
• Replace a score display glass
• Bally and Stern score display boards
• Score display J1 to MPU J1 connections
• Seven-digit and six-digit displays
• One segment always lit on a display
• Score displays dim
• First checks before repairing Bally score displays

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