FANUC Alarm SRVO-047 — SERVO LVAL alarm
Error- Hardware
- servo amplifier
- Controllers
- R-J3iB / R-30iA / R-30iB
- FANUC class
- SERVO
Manufacturer wording — SERVO LVAL alarm(Group:%d Axis:%d)
The manual prints placeholders; your controller fills them in with the real group, axis or number.
FANUC SRVO-047 (“SERVO LVAL alarm”): Despite the external magnetic contactor for a servo amplifier being on, the DC voltage (DC link voltage) of the main circuit power supply or the control power supply voltage (+5 V) is excessively low. First check: When the LED indicator on the servo amplifier displays '6' (this alarm is issued when the control power supply voltage (+5 V) is excessively low): 1. Likely part: Servo amplifier (Servo amplifier).
Updated 2026-10-22 · LogrobotLM reference
Description
Despite the external magnetic contactor for a servo amplifier being on, the DC voltage (DC link voltage) of the main circuit power supply or the control power supply voltage (+5 V) is excessively low.
Remedy
When the LED indicator on the servo amplifier displays '6' (this alarm is issued when the control power supply voltage (+5 V) is excessively low): 1. Replace the servo amplifier. 2. Replace the power supply PCB.
Field diagnosis
The internal control voltage of the amplifier (5 V and associated voltages) is too low.
What to check
- Check the upstream power supply; replace the amplifier, then the power supply unit if the code persists.
- Note: On R-30iA Mate, the PSM variant is SRVO-131.
Part to check / replace
FANUC SRVO-047 points to the hardware below — start here before ordering.
Tap a part for every code that points to it — and verify the exact variant for your controller before ordering.
Related codes
Same hardware involved
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 →