The credit (start) button never registers, not even in switch test, though the wiring from the switch back to its connector tests good. (Earlier, a whole column of playfield switches had been dead because a column wire had come off a drop target switch.)
Credit button does nothing in switch test: daisy-chained coin door wire come loose
Cause: The coin door switches are daisy-chained together; a red/yellow wire in that chain had come undone, cutting the credit button off.
Checks
- Follow the credit button's wires through the coin door and coin chute switches, checking every joint where the daisy chain passes from switch to switch.
- For a whole dead row or column of switches, look for a common wire broken off at one of the switches it links.
Fix
- Resolder the loose daisy-chain wire.
Systems
Games
Related tips
- Drop target and spinner on one switch row dead: wire hanging off the slam tilt switch
- One drop target only registers if it is the first one down: reseat and clean the PIAs
- Strange game behaviour from a grounded start button
- One target also scores its neighbour: a stray switch jumper elsewhere
Source: Pinball Repair help group!! (Facebook group)