The same segment is missing in every digit of one or more displays.
Missing segment on one or more score displays
Cause: Segments leave the CPU on J2. On all displays suspect Z16 (7404), the main segment chip. On a pair of displays suspect the 74175/7448 pair that serves them, most often the 7448: Z18/Z19 for players 1 and 2, Z20/Z21 for players 3 and 4, Z22/Z23 for the bonus and four-digit status displays. On one display, suspect the driver chip on that display.
Checks
- Match the affected displays to the chip pair.
- Check J2 for poor contact.
Fix
- Replace the 7448 first, then its 74175, or Z16 if every display is affected.
System 80/80A displays run on about 60 V DC; switch the game off before unplugging or touching a display or its connector.
Systems
Related tips
- Display chips on the CPU board fail after swapping displays
- Gottlieb System 80: bottom segment missing on one display that follows it: replace Z1
- Scores show only a single 0 and the credit display is blank: failed 7404 at IC31
- Restoring brightness on 4, 6 and 7 digit display boards
- Damage after the black and white plugs were swapped
- Guarding the fill tip on the back of a score display
- One six-digit display completely dead
- Boot stops after the ninth LED flash: IRQ fault
Source: Repairing & Upgrading Gottlieb System 80 Pinballs from 1980 to 1989, Part Two, Clay Harrell (pinrepair.com)