Clear any interlocks if possible, power on the CNC, and release the emergency stop.
The 414 alarm is a "system-level" notification. To find the root cause, you must look deeper into the machine's diagnostics: CNC Diagnostics: Diagnostic No. 200 or 204
On Fanuc control systems (such as the Fanuc 0-M, 16i, 18i, or 21i), . It triggers when the CNC logic board or the servo amplifier module (SVM) registers an abnormal electrical or signal state.
: Points to a Disconnection Alarm in the pulse coder or feedback loops. Reading the Servo Amplifier Hardware Display fanuc 414 servo alarm z axis detect error repack
I can then provide specific steps to test your cables or motor.
When a motor is repacked, a skilled technician will completely disassemble it. The process typically involves:
, the fault is in the servo amplifier itself. 4. Check Mechanical Binding Clear any interlocks if possible, power on the
Disconnect the Z-axis motor power cable (U, V, W lines) directly from the bottom of the servo amplifier.
The dry nut causes :
Restart the machine. If the alarm , the fault is in the motor or cable . If it remains , the amplifier is likely defective. 200 or 204 On Fanuc control systems (such
If you get to this point and have isolated the problem to the motor itself, you have a choice: replace or "repack". In the context of CNC maintenance, a "repack" isn't about packaging—it's professional slang for a servo motor.
Fanuc servo motors typically use absolute encoders. These encoders "remember" the position of the machine even when powered off. This memory is maintained by batteries (usually located in the servo amplifier cabinet or separate battery packs).
at 1000V. A standard multimeter may not detect insulation failure. : Faulty axis control cards (e.g., A20B-2902-0290
: General power supply or axis control card failure. 2. Check the Diagnostic Screen Diagnose a Fanuc High Current Alarm in 10-Steps
: Ensure the Z-axis can move freely. Mechanical resistance can force the motor to draw excessive current, triggering the alarm. Advanced Troubleshooting (Diagnostics)