Fanuc · Series 20 CNC
This alarm indicates a critical error within the Central Processing Unit (CPU) of the Fanuc Series 20 CNC. This signifies a severe malfunction in the CNC's core processing unit, leading to system failure and preventing any machine operation.
Click steps to track your progress.
Power cycle the CNC completely to attempt a CPU reset.
Check all cooling fans on the CNC main unit and ensure clear airflow to the CPU heatsink. Verify ambient temperature.
Measure the input power supply voltages to the CNC main board for stability and correct levels.
Inspect the CNC main board for any visible damage, burn marks, or swollen capacitors.
If the alarm persists, the CPU or the entire CNC main board is likely faulty and requires replacement.