Switch diodes are on the A17 board, not the switches
Playfield switch diodes sit on one board under the playfield, usually near the outhole. A replacement switch needs no diode, but finding a bad diode means working out which one on the board belongs to the switch.
Systems
Related tips
- A whole row of eight switches dead
- Smart Switch pin 1 and pin 2
- What is inside a Smart Switch
- Catching random switch closures
- Proving the driver board's switch strobes
- Gottlieb Smart Switches (piezo)
- Closing one switch shows several in the same column
- Lamp and switch matrix size and drivers
Source: Repairing Gottlieb System 3 Electronic Pinball Games from 1989 to 1996, Clay Harrell (pinrepair.com)