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FANUC Alarm SRVO-123 — Fan motor rev slow down(i)

Warning
Hardware
cabinet cooling
Controllers
R-30iB (this generation only)
FANUC class
WARN (default, not tabulated in the sources)
Hardware family
FANUC cabinet cooling and overheat alarms

FANUC SRVO-123 (“Fan motor rev slow down(i)”): The rotation speed of a fan has dropped without it stopping completely.

Updated 2026-10-22 · LogrobotLM reference

What it means

The rotation speed of a fan has dropped without it stopping completely.

What to check

  • Replace the fan and check its cable; then the backplane unit; main board last, after backup.
  • Note: R-30iB code: precursor of SRVO-014, to be dealt with before the fan stops.

Related codes

SRVO-014WARN Fan motor abnormalSRVO-015SERVO System over heatSRVO-121SERVO Excessive acc/dec timeSRVO-122SERVO Bad last ang(internal)SRVO-124Check HardStop if HitSRVO-125WARN Quick stop speed over

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 →