F

Resistor Module Abnormal Discharge (1) (ECM)

Fanuc · Alpha i Series AC Servo Motor and Spindle

What does F mean?

The Capacitor Modules are not discharging as expected, indicating a potential malfunction of the discharge circuit or the Resistor Module itself.

Common Causes

  • The braking resistor module is experiencing an abnormal discharge condition (first instance).
  • Faulty braking resistor element or connection.
  • Internal control signal error related to braking resistor activation.
  • Over-temperature detected within the braking resistor module.
  • Unexpected rapid discharge of energy through the resistor.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Inspect the Resistor Module and its connections for damage or open circuits.

  2. 2

    Verify the control signals for initiating discharge.

  3. 3

    Check the Capacitor Modules for any condition preventing discharge.

Browse all codes in this manual (29)
Verified technical data. Last updated: March 2026

Related Faults

Source: Fanuc Alpha i Series AC Servo Motor and Spindle