A whole digit position is blank on one or more displays.

Missing digit on one or more score displays

Cause: The digit lines leave the CPU board on J3. A digit missing on every display points at Z25 (74154), which feeds the three digit driver chips. Missing on two displays points at one of those drivers: Z17 serves players 1 and 3 and the bonus display, Z24 players 2 and 4 and the credit/ball display, Z26 the status display. On a single display, suspect the display itself.

Checks

• Note which displays share the fault and match them to Z17, Z24 or Z26.
• Check J3 for poor contact.

Fix

• Replace the chip indicated, or repair or replace the one display.

System 80/80A displays run on about 60 V DC; switch the game off before unplugging or touching a display or its connector.

Systems

• Gottlieb System 80
• Gottlieb System 80A

Related tips

• Displays never show the digit 1
• Display chips on the CPU board fail after swapping displays
• Scores show only a single 0 and the credit display is blank: failed 7404 at IC31
• Digits burning or faint on players 1 and 3 (or 2 and 4)
• Gottlieb System 80: bottom segment missing on one display that follows it: replace Z1
• F-14 Tomcat: left credit-display character scrambled
• Restoring brightness on 4, 6 and 7 digit display boards
• Blanking circuit parts: C32/C84, IC7, Q5/Q1 and IC23

Source: Repairing & Upgrading Gottlieb System 80 Pinballs from 1980 to 1989, Part Two, Clay Harrell (pinrepair.com)