Testing a coil diode
Steps
- Cut one diode lead free of the coil lug (or simply replace a suspect diode; they are cheap and often visibly broken).
- Meter on diode test: black probe on the banded end, red on the other. Expect 0.4-0.6 V.
- Swap the probes: there should be no reading.
- If either result is wrong, fit a new 1N4004.
- If the diode is good, resolder the cut lead.
Systems
Related tips
- Testing the diode on a coil
- What the coil diode does and how a bad one shows up
- Which way a coil diode goes
- Which way a coil diode goes
- Always check the coil diode when a driver transistor has failed
- Testing a coil diode on the driver board
- Testing the diodes on a flipper coil
- Coil diode and wire orientation when replacing a coil
Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Two, Clay Harrell (pinrepair.com)