ALM LED Blink (3:1)

Power Failure (Subsequent Unit)

Fanuc · R-30iB Mate + Mate Plus Robot

What does ALM LED Blink (3:1) mean?

The red ALM LED blinks with a 3:1 duty cycle (1.5s ON / 0.5s OFF), indicating a power failure (which may include instantaneous power failure) in a unit subsequent to the unit of interest. This signifies a power supply interruption downstream from the current unit.

Common Causes

  • A power failure or significant voltage fluctuation has occurred in the subsequent unit or module connected to the main system.
  • The power supply to an external component has been interrupted, causing it to go offline.
  • This could be due to an issue with the external unit's power supply, the wiring to it, or a main power disturbance.
  • The control system has detected a loss of operational power in a connected device.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Identify and remove the cause of a power failure in a unit subsequent to the unit of interest.

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Verified technical data. Last updated: March 2026

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Source: Fanuc R-30iB Mate + Mate Plus Robot