Fit a coil diode with its band on the power lug
The banded end of the diode goes to the coil's power lug: the lug carrying the heavier red or purple wire, usually two wires because power daisy-chains from coil to coil. A diode fitted backwards shorts the moment power is applied and can blow a fuse or the driver transistor.
Systems
Related tips
- Check every coil's resistance before first power-up
- Which coil lug takes which wire
- Firing a coil by grounding its ground lug
- Measure every coil before powering up new driver transistors
- Always check the coil diode when a driver transistor has failed
- Voltage on only one lug of a coil
- No voltage at either lug of a coil
- Constant power coil drivers Q8-Q13 and Q23-Q30
Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Two, Clay Harrell (pinrepair.com)