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FANUC Alarm SRVO-264 — SYSTEM E.STOP circuit abnormal 1

Error
Hardware
emergency stop and dual safety chains
Controllers
R-J3iB / R-30iA
FANUC class
SYSTEM
Hardware family
FANUC emergency stop, pendant and dual safety chain alarms

FANUC SRVO-264 (“SYSTEM E.STOP circuit abnormal 1”): MON3 status is ON when servo is ready The status of MON3 is abnormal First check: Repair the circuit of MON3 on E.STOP unit

Updated 2026-10-22 · LogrobotLM reference

Description

MON3 status is ON when servo is ready The status of MON3 is abnormal

Remedy

Repair the circuit of MON3 on E.STOP unit

Field diagnosis

The emergency stop unit is faulty: loose connector or failed internal circuit.

What to check

  • Reseat all connectors of the emergency stop unit, then replace the unit if the code returns.
  • A power cycle is required to clear.
  • Note: Tends to appear after work inside the cabinet: a connector that was not properly reseated.

Related codes

SRVO-265SERVO E.STOP circuit abnormal 2SRVO-250SERVO SVEMG/MAINON1 abnormalSRVO-207SERVO TP switch abnormal or Door openSRVO-262SERVO Chain 1 (SVDISC) abnormalSRVO-263SERVO Chain 2 (SVDISC) abnormalSRVO-266SERVO FENCE1 status abnormal

Indicative field information — the robot manufacturer's manual and safety procedures always prevail. Never bypass a safety device; apply lockout/tagout (LOTO) before any physical intervention. How this reference is built →