None of the six lamps on the small board under the lower part of the upper mini playfield ever light, though the bulbs are good; the rest of the mini playfield lamps work.
All six lamps on the mini playfield lamp board never light: cold joint on the common pin
Cause: A cracked (cold) solder joint on the board's common connection that feeds all six sockets.
Checks
- Check whether the dead lamps share a board and a common feed rather than one matrix row or column.
- Test the lamp diodes in diode mode, not continuity mode: a good diode reads about 0.5 V one way and open the other.
- Inspect and continuity-test the board's common pin and traces.
Fix
- Reflow the cold joint on the common pin.
Games
Source: Pinball Repair help group!! (Facebook group)