A new game resets the ball count to 1 correctly, and at the end of each ball the bonus counts and the ball is served, but the ball count never advances.
Ball count stays at 1 after each drain: dirty secondary trough switch
Cause: The P relay, which pulses the ball count unit, was not being energized because the secondary trough switch (closed when the ball is ejected from the trough) was dirty or out of adjustment. This game has that switch even though repair guides describe it as a later feature.
Checks
- Make sure the ball count unit advances when its coil plunger is pushed in by hand.
- Trigger the P relay by hand during bonus count: if the ball count then advances, the problem is in what energizes the P relay.
- Find the secondary trough switch and watch whether it closes when the ball is kicked out.
Fix
- Clean and adjust the secondary trough switch so it closes reliably when the ball is ejected.
Systems
Games
Related tips
- Game stuck on player 1, ball 1: broken wire on the ball index relay
- Hitting targets runs the ball count to game over: shorted rollover switch
- Game Over relay trips again right after start: dirty Lock relay switch
- Next ball sometimes not served after a drain: C relay path switches, then new rubbers
- Game resets but the outhole relay never fires: feed wire hanging by a strand
- Ball count stepper won't advance: pawl arm frozen in old grease
- Score motor runs on at game over: end game relay not pulling in
- Ball count drops by one as the first ball is served: stuck 10-point playfield switch
Source: Pinball Repair help group!! (Facebook group)