NMI Alarm in BOC (Base Board Controller)
Fanuc · Series 20 CNC
What does 970 mean?
This alarm indicates a Non-Maskable Interrupt (NMI) originating from the Base Board Controller (BOC) within the Fanuc Series 20 CNC. An NMI is a critical, high-priority interrupt that usually signals a serious hardware malfunction that the CPU cannot ignore, often leading to a system halt.
Common Causes
- Faulty BOC hardware or associated circuitry on the CNC main board.
- Memory error on the BOC or related components.
- Power supply irregularities affecting the BOC.
- Overheating of the BOC or surrounding components.
- ESD damage to the BOC.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Power cycle the CNC system to attempt a reset of the BOC and clear the NMI.
- 2
Verify stable and clean power supply to the CNC main board, checking for voltage drops or spikes.
- 3
Inspect the CNC main board for any visible damage, such as burn marks or damaged components in the BOC area.
- 4
Ensure adequate cooling inside the CNC cabinet and check for proper fan operation and clear airflow.
- 5
If the alarm persists, it indicates a hardware fault on the CNC main board related to the BOC, requiring replacement of the main board.