Check drive-related rails/signals and connector stability.
Fault route
LGK100L Burns IGBT Diagnostic
A repeat-IGBT-failure workflow for LGK100L plasma cutters focused on root cause, not only part replacement.
Quick Answer
LGK100L repeated IGBT failure should not be treated as an IGBT-only fault. The source workflow points to control-board output balance, detection inductor continuity, filter capacitor condition and inverter board condition.
- Check control-board drive-related voltage/signal evidence before installing another IGBT.
- Loose X3 connector or open detection inductor can contribute to IGBT failure.
- Filter capacitor failure or inverter-board fault can keep destroying IGBTs.
Use this page when
- IGBT burns or fails repeatedly.
- A previous IGBT replacement did not solve the fault.
- You need to prevent re-damaging new power devices.
Do not use this page when
- The machine has never powered up.
- Breaker trip is being checked for the first time.
- Only weak current is present without IGBT damage.
LGK100L burns-IGBT route
Do not replace the module alone; check what caused it to fail.
Loose connector or open detection inductor can corrupt protection/detection.
Failed capacitors can stress the inverter stage.
Driver indicator/behavior and IGBT condition must be checked together.
If upstream evidence is normal, inverter board becomes suspect.
IGBT repeat-failure evidence table
| Evidence point | Expected / abnormal evidence | Repair direction |
|---|---|---|
| Control-board connector / drive evidence | Abnormal or missing expected drive-side evidence. | Repair control/drive path before installing new IGBT. |
| X3 connector | Loose connector can break detection/control feedback. | Repair connector/harness. |
| Detection inductor | Open detection inductor can trigger wrong operation/protection behavior. | Repair/replace detection inductor. |
| Filter capacitors | Burned or failed filter capacitors stress inverter stage. | Replace failed capacitor section. |
| Driver board / IGBT | Driver indicators and IGBT visual/short evidence matter together. | Replace IGBT and driver if the evidence points to both. |
| Inverter board | Persistent failure after checks. | Replace/repair inverter board. |