Score display J1 to MPU J1 connections

Display J1 (20-pin .156"): pin 1 high voltage; pins 4-9 digit enables D1 (ones) to D6 (hundred-thousands), from MPU J1 pins 1-6; pin 12 millions enable D7 on 7-digit games, from MPU J1-7; pin 10 blanking (MPU J1-10); pin 13 ground; pin 15 latch strobe (MPU J1-20); pins 16-19 BCD data 3 to 0 (MPU J1-28 to J1-25); pin 20 +5 V. Buzz each MPU J1 pin through to the player 1 display; a broken J1 pin can, for example, make every display show 8 instead of 0.

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
• One digit missing on a score display
• Score display digit parts by position
• Score displays dim
• First checks before repairing Bally score displays
• All score displays blank with the MPU fully booting

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