9073

Sensor Signal Disconnection Alarm

Fanuc · Alpha i Series AC Servo Motor and Spindle

What does 9073 mean?

This alarm indicates an incorrect detection of a sensor signal disconnection, potentially due to wiring issues in the motor terminal box or non-shielded cable portions. This can also lead to large variations in low-speed motor operation.

Common Causes

  • Physical disconnection of sensor wiring to the control module.
  • Damaged sensor cable or connector.
  • Sensor has failed and is no longer transmitting a signal.
  • Interference on the sensor signal line.
  • Faulty input port on the control module.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Inspect the wiring in the motor terminal box (transit box for built-in motors) to ensure proper connections and minimize non-shielded cable portions.

  2. 2

    Check the feedback cable for physical damage or loose connections between the spindle motor and amplifier.

  3. 3

    Verify all sensor signal connections (e.g., JFx connector for pulse coder, JYA2 for spindle sensor) for secure contact.

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