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ABB Error 39426 — Rectifier internal failure

Error

ABB 39426 (“Rectifier internal failure”): Rectifier internal failure: the rectifier on the communication link reports an internal failure. Likely part: Rectifier / rectifier-to-drive signal cable.

Updated 2026-10-22 · LogrobotLM reference

What it means

Rectifier internal failure: the rectifier on the communication link reports an internal failure. Can be caused by a missing or faulty signal connection between the rectifier and the drive units.

What to check

  • Before concluding that the rectifier has failed, check that the signal cable is correctly connected between the rectifier and the drive unit, at both ends.
  • Reseat the connectors.
  • Perform a full shutdown and restart.
  • If the error persists, isolate and then replace the rectifier.
  • Note: So-called "internal" error, but whose most frequent cause is external (signal cable): a typical illustration of the internal-error trap at the end of the Elog.

Part to check / replace

ABB 39426 points to the hardware below — start here before ordering.

Tap a part for every code that points to it — and verify the exact variant for your controller before ordering.

Related codes

32540Drive unit / firmware fault32541Drive unit / firmware fault39008Drive units fault

Indicative field information — the robot manufacturer's manual and safety procedures always prevail. Never bypass a safety device; apply lockout/tagout (LOTO) before any physical intervention. How this reference is built →