Firing a coil by grounding its TIP122/TIP102 tab
Steps
- Put the game in diagnostics and take out the backglass (close the coin door on WWF Royal Rumble and later).
- Find the TIP122/TIP102 for the coil or flasher in the manual.
- Clip a jumper to the backbox floor ground strap and briefly touch the other end to that transistor's metal tab. The device should fire.
- If not, it may be on the other L/R bank: ground Q29's tab with a second jumper and try again.
- For a TIP36c-driven coil, ground the tab of the TIP122/TIP102 that pre-drives it instead.
Only do this on TIP122/TIP102 tabs; grounding a TIP42 or TIP36 this way can damage parts.
Systems
Related tips
- Check every coil's resistance before first power-up
- Testing the L/R select relay by grounding Q29
- Always check the coil diode when a driver transistor has failed
- Finding a coil's driver transistor without a manual
- Several bank-switched coils or flashers dead, or firing the wrong device
- Constant power coil drivers Q8-Q13 and Q23-Q30
- Use the manual's coil/flasher chart to find driver transistors
- A low resistance coil means checking its driver chain too
Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Two, Clay Harrell (pinrepair.com)