Fanuc alarm 27
αi SPM · Fanuc αi SPM
What it means
Position coder disconnected - alpha position coder (spindle encoder) signal lost.
Likely causes
- Position coder feedback cable broken or connector bad contact
- Coolant ingress in connector
- Sensor-setting parameter incorrect
- Cable shielding faulty or bundled with servo power leads
- SPM control PCB failure
Triage note: CNC: SP0027 / 9027. Alarm only when cable moved = conductor fracture; only when rotating = shielding/routing problem.
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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Spindle position coder cable per machine
Encoder Feedback Cable · Primary suspect
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A860-03Txx position coder / built-in spindle sensor
Spindle Position Coder · Common cause
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SPM control PCB per model
Amplifier Control Board · Check if others ruled out
Need the part urgently?
Send us alarm 27 with your machine details — typical RFQ turnaround is 24–48h.