Alarm guide · Fanuc · Updated October 2026
Fanuc SV0361 alarm: abnormal phase data (pulsecoder)
Fanuc SV0361 means the built-in pulsecoder reported abnormal phase data. It points to the pulsecoder or its cable.
By Suresh Sankaran, founder of Star Automations, servo motor repair since 1998.
What the alarm means
The phase data from the pulsecoder is not valid. Alarm numbers and wording can differ between series, so confirm with the manual for your unit.
Common causes
- Pulsecoder fault
- Cable fault
- Connector contact
- Noise
- Moisture in the encoder
Safe first checks
General guidance only. Follow the drive manual and your site's electrical safety rules. Power off, and let the DC bus discharge, before touching connectors.
- Note the exact alarm code and when it appears: at power-up, at start, or under load.
- Power off and turn the shaft by hand if safe: it should turn smoothly.
- Check the motor cable, encoder cable and connectors for damage and loose contacts.
- Check what changed recently: load, speed, settings, cables or a replaced part.
When to send it for repair
Send the motor for pulsecoder testing, repair and alignment.
We test every motor on our Universal Servo Motor Repair Equipment, which reads and aligns the feedback and runs the motor under load without the original drive.
See Fanuc servo motor repair, Fanuc encoder repair and Fanuc servo drive repair.
Questions
Is it the cable or the pulsecoder?
Check the cable first. If it stays, bench testing shows the pulsecoder condition.
How long does repair take?
Emergency repair is done the same day where the fault and parts allow, urgent in 3 working days and standard in 7 working days, counted from when the unit reaches our bench and the quote is approved. Every unit returns with a printed test report.
Can I get an exchange unit?
If we hold a matching unit, Servo Swap ships a tested exchange unit while yours is repaired. Mark "line down" on the request form and add the part number.
Related: SV0414 · SV0364 · SV0368 and SV0366
Brand names identify the units we repair. Star Automations is an independent multi-brand repair company and is not an OEM service centre.