Fault index

Power Device Failure Index

A power-electronics repair index for welders with IGBT, MOSFET, rectifier, driver, output-diode or repeated-failure symptoms.

Start here

Use this index when the machine trips the breaker, burns IGBTs/MOSFETs, has a shorted rectifier bridge, blows replacement devices, or loses output through secondary diode/load faults.

Root-cause principle

A blown IGBT or MOSFET may be a result, not the root cause. Driver supply, gate output, feedback, overcurrent protection, snubber/bus capacitor condition and output load should be checked before powering replacement parts.

Safe repair order

First isolate input/DC bus shorts, then test rectifier bridge and bus capacitors, then gate-driver and power devices, then output diode/secondary load, then staged power-up or precheck.

Start from these records