How wiring faults show up in switch test
Column to ground: closing any switch in that column lights its whole row. Row to ground at the diode anode: the whole row shows closed. Row to ground at the cathode: that row shows closed. Two columns shorted: a switch also shows its twin in the other column, same row. Two rows shorted: a switch also shows its twin on the other row, same column. Row shorted to column: the switch at their crossing reads closed. Open diode: only that switch is dead. Shorted diode: false readings when other switches on that row are closed.
Systems
Related tips
- Standard switch and diode wiring
- One playfield switch does not register
- All eight drop targets never register: check the drop target board plugs
- A switch does not register in the switch test
- Using the System 11 switch tests
- A whole switch row reads as the next row: fault in the row wire harness
- System 11 switch matrix differences
- Entering the System 11 switch tests
Source: Repairing Williams System 11 Pinball 1986 to 1990, Part Three, Clay Harrell