After the boards came back from a rebuild the game played and spoke normally, but the score displays showed nothing apart from a faint orange glow inside the tubes.
Score displays dead but digits glow: bad wire in the CPU blanking plug (1J3)
Cause: One wire in the female plug on the CPU board connector that carries the display blanking signal (printed as 1J3 on the board, but check your manual) wasn't making contact, so the displays stayed blanked.
Checks
- A glow in the displays means the high voltage is reaching them, so the display fuse is probably fine.
- Check every connector on the CPU board and on the master display board is fitted in the right place.
- Tug each wire in the display connectors on the CPU board, and check continuity from the plug to the display board.
Fix
- Repin or reterminate the loose wire in the female plug and reseat it.
The display circuits run on high voltage (around 100V or more); unplug the game before handling display connectors.
Systems
Games
Related tips
- All score displays dead
- One score display dead
- Digits burning or faint on players 1 and 3 (or 2 and 4)
- Displays have high voltage but stay blank
- CPU LEDs flash and go out but the score displays stay dark
- Ball and credit displays show only even numbers after header work
- A segment missing on a score display
- Solenoid fuse F2 blows at power-up as every coil fires: CPU blanking circuit
Source: Pinball Repair help group!! (Facebook group)