As soon as the game is turned on, every display strobes "000000", instead of staying blank for about 4 seconds and then alternating zeros with the high score.
All displays flash "000000" at power-on: open slam circuit
Cause: Before Big House the slam switch is a normally-closed contact that must stay made; it is open, dirty or bent, or its wire or CPU A1-J5 pin 10 connection has failed.
Checks
- Check the slam switch on the coin door.
- Check continuity of the wire from the switch to A1-J5 pin 10 and the pin itself.
Fix
- Repair the switch, wire or pin, or do the permanent slam switch modification.
Systems
Related tips
- Game won't start or boot because the slam circuit is open
- System 80 switch matrix diodes
- Testing the switch matrix inputs with the test EPROM
- Missing digit on one or more score displays
- Niwumpf replacement CPU board takes about 10 seconds to show scores
- System 80B displays stuck in reset
- CPU board connectors A1J1 to A1J3 (power and displays)
- Missing segment on one or more score displays
Source: Repairing & Upgrading Gottlieb System 80 Pinballs from 1980 to 1989, Part One, Clay Harrell (pinrepair.com)