Servo System Error (Generic)

What does 405 mean?

These alarms (404 and 405) generally indicate a fault within the servo system that prevents proper axis operation. Without further detail, they point to an unspecified servo system abnormality affecting the Fanuc Series 20 CNC.

• Unspecified servo motor or amplifier malfunction.
• Feedback system error (e.g., encoder signal loss, communication issue).
• Control board malfunction in the CNC or servo amplifier.
• Power supply irregularities to the servo system.
• Software or parameter inconsistencies in the servo control.

Click steps to track your progress.

1. 1

   Check the servo amplifier's status LEDs for any specific fault codes or indicators and cross-reference them with the amplifier manual.

2. 2

   Power cycle the CNC and servo amplifiers to attempt a system reset.

3. 3

   Inspect all power and feedback cables connecting the servo motors to the amplifiers and amplifiers to the CNC for damage or loose connections.

4. 4

   Review the servo parameters for any recent changes or inconsistencies that might lead to system instability.

5. 5

   If the problem persists, isolate the faulty component by swapping servo motors or amplifiers (if identical axes are available) with known good ones.