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CNC alarm code troubleshooting

CNC alarms by control, model and alarm number: FANUC, Haas, Siemens SINUMERIK and more. Each guide gives the meaning, the ranked causes and the check that confirms each one, and cites the maintenance manual it is based on.

By CNC control

FANUCSeries 0i-F / 0i-F Plus

11 fault-code guides

Haas AutomationNext Generation Control (NGC)

4 fault-code guides

SiemensSINUMERIK 840D sl / ONE

3 fault-code guides

By symptom

SymptomCNC losing its reference position

Why a CNC asks for a reference return after power-off: encoder battery, cables, encoder faults and home switches, with FANUC, Haas and Siemens alarms.

SymptomCNC axis following error (excess error)

Why a CNC axis trips on following error (excess error): binding, brakes, cables, tuning and limits. FANUC SV0411, Haas 103, SINUMERIK 25050 compared.

Overview

Machining centres report most problems as numbered alarms from the control, spindle or servo drives. Load and temperature history around the alarm tells you whether it is a one-off or a trend.

Common problems

Spindle overload or overheating

Trend spindle load and temperature against the program running at the time.

Servo and drive alarms

Note the axis and alarm number, and check whether it repeats on the same move.

Dimensional drift

Compare part measurements with machine warm-up and coolant temperature.

Evidence that helps

  • Photo of the alarm screen
  • Control make and model
  • Spindle load and temperature history
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