Use a real ball in the switch test
Enter the switch level ("TST") test and roll a ball over or into each switch rather than pressing it with a finger; this closes the switch the way play does, and the display should show it.
Systems
Related tips
- What a bad switch diode does
- Which switches are outside the switch matrix
- Clearing a switch from the power-on switch report
- Test a leaf switch diode in place
- Check the switch matrix with a logic probe
- Resistor networks in the switch matrix
- Using the test EPROM burn-in to find closed switches
- Switch column (drive) circuit on the CPU board
Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Three, Clay Harrell (pinrepair.com)