Fanuc 414 Servo Alarm Z Axis Detect Error Page

This is a technical deep-dive into the FANUC 414 Servo Alarm: Z-Axis Detect Error (often displayed as SV0414 or 414 on the CNC control).

• Look for cuts, kinks, oil ingress, or crushed sections.

3. Troubleshooting Sequence (Step-by-Step)

Step 1: Visual & Mechanical Check

• Inspect Z-axis brake: On vertical mills, the Z-axis (headstock) has a holding brake. If the brake fails to release, the motor cannot turn → immediate 414 alarm.
• Check for binding: Move Z-axis manually (handwheel) with servo off or by turning the motor fan. Feel for rough spots or excessive resistance.
• Check coupling: Ensure motor-to-ballscrew coupling is tight.

Once you've identified the cause of the alarm, you can take steps to resolve the issue: fanuc 414 servo alarm z axis detect error

2. How the Detection Works

The CNC uses a dual-check method to confirm encoder feedback: This is a technical deep-dive into the FANUC

The Z-axis is unique because it must constantly fight gravity. Common root causes include: Diagnose a Fanuc High Current Alarm in 10-Steps Look for cuts, kinks, oil ingress, or crushed sections

“414 Z-axis detect error” is rarely a mechanical problem (ballscrew/bearing). It’s almost always electrical: broken encoder cable, failed drive, or less often a bad motor encoder. Don’t pull the ballscrew – check the wires first.

2. Servo Amplifier (Drive Unit) Failure (≈30%)