Using the test EPROM burn-in to find closed switches
During burn-in the test program cycles solenoids, lamp patterns, display and sounds. If any switch matrix position reads closed, the lamp patterns pause and the lamp at the same row and column position lights, so a stuck switch or matrix short shows straight away after power-on.
Systems
Related tips
- What a bad switch diode does
- An entire switch row shows closed all the time
- One switch shows closed though it is open
- Which switches are outside the switch matrix
- Use a real ball in the switch test
- Closing one switch shows its whole row closed
- False switch readings only when several switches are closed
- Clearing a switch from the power-on switch report
Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Two, Clay Harrell (pinrepair.com)