The A15 flipper sensor board
A small board under the playfield senses the cabinet flipper buttons through an opto-isolator and two 2N3906 transistors, and reports them to the CPU as switch matrix inputs.
Systems
Related tips
- How the Sega opto receiver works
- System 80B displays stuck in reset
- Flippers dead in a game
- All System 3 games use Gottlieb's thin flippers
- Gottlieb large flipper coils by wrapper colour
- Replacing a flipper coil
Source: Repairing Gottlieb System 3 Electronic Pinball Games from 1989 to 1996, Clay Harrell (pinrepair.com)