Fanuc alarm 73
αi SPM · Fanuc αi SPM
What it means
Motor sensor disconnected - MZi/BZi spindle motor sensor signal lost.
Likely causes
- Sensor cable broken / connector bad contact (especially when alarm follows cable movement)
- Sensor signal out of adjustment or dead
- Shielding fault / cable bundled with power leads
- SPM control PCB failure
Triage note: CNC: SP0073 / 9073. Adjust sensor signal per manual; replace sensor+cable only if signal cannot be recovered.
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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MZi/BZi sensor + cable set per motor model
Spindle Sensor Kit · Primary suspect
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SPM control PCB per model
Amplifier Control Board · Check if others ruled out
Need the part urgently?
Send us alarm 73 with your machine details — typical RFQ turnaround is 24–48h.