To troubleshoot the Fanuc 414 servo alarm, follow these steps:

To pinpoint the exact internal failure, check the following diagnostic bits on the CNC screen: Diagnostic No. 200 : Check bits for specific errors: Bit #7 (OVL) : Overload condition. Bit #6 (LV) : Low voltage in the servo amplifier. Bit #5 (OVC) : Overcurrent detected by digital servo software. Bit #4 (HCA) : Abnormal current (High Current Alarm) in the amplifier. Bit #2 (DCA) : Regenerative discharge circuit alarm. Bit #1 (FBA) : Feedback cable disconnection. Diagnostic No. 204

Abnormal current alarm (often a short circuit or faulty amplifier).

When the Z-axis triggers a 414 alarm, the CNC detects abnormal current flow or feedback signals. Common triggers include: High Current Alarms (HCA): Often appearing as codes 8, 9, or A on the servo amplifier's physical LED display. Electrical Shorts:

The "detect error" specifically points to a mismatch in the between the commanded position and the actual position feedback. The CNC sees this as a loss of control and immediately disables the servo drive to prevent a crash.

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