What the SRVO-044 alarm means

The DC link voltage inside the amplifier exceeded the upper limit. This is a routine repair in our workshop for FANUC R-30iA / R-30iB / R-30iB Plus systems, and we normally pin it down during the first site check.

Most common causes

  • Incoming power voltage too high or transformer tap set wrong
  • Regenerative energy not discharged (see SRVO-043)
  • Amplifier internal voltage detection fault
Field note: Begin with the first item in the list; it has a far higher on-machine occurrence rate than the others.

Step-by-step field fix

  1. Measure incoming 3-phase voltage and check transformer tap settings
  2. Check discharge resistor circuit
  3. If voltage is normal and alarm persists, the amplifier detection circuit is likely faulty - replace amp
Safety first: For FANUC srvo-044, servo circuits are live and motor shafts and reducers rotate: measuring current waveforms or winding resistance means contact with live or moving parts. The self-serviceable action is Measure incoming 3-phase voltage and check transformer tap settings; anything past that falls under live servo circuits and rotating parts and needs a certified engineer.

How we diagnose servo alarms on site

FANUC srvo-044 belongs to the servo & drive family. On FANUC srvo-044 the failing stage is alpha-i / beta-i servo amplifiers with PSM supply modules and SVM servo modules (SPM where spindles fit) on the R-30iB Plus / R-30iB Mate Plus / R-30iA - the servo closed loop: current/velocity/position loop misbehaviour, motor-drive matching and load identification. We start reading FANUC srvo-044 at the iPendant ALARM screen (SRVO / MOTN / SYST / INTF prefixes) together with the amplifier's 7-segment status code.

The chain involved in FANUC srvo-044 runs: target -> position loop -> velocity loop -> current loop -> power output -> motor -> feedback -> loop compare.

Incoming power voltage too high or transformer tap set wrong on FANUC srvo-044 needs two causes separated first: A servo motor whose brake never fully opens runs overloaded and reports overcurrent or overload - it looks like a dead drive. Insufficient coil supply, a sticking lining or a wrong gap all produce this running-on-brake condition. The other case is turn-to-turn winding shorts: one phase reads high current and the motor runs hot. We measure brake coil supply and actuation current first, then winding resistance balance across the three phases; only when both are wrong do we talk about replacing the motor.

Field notes on this page cover FANUC srvo-044 (HVAL Alarm - High Voltage); written by the Henghuan repair team, updated 2026-10-01.

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Related Servo & Drive alarms

SRVO-021 — SRDY Off (Group / Axis) SRVO-023 — Stop Error Excess (Group / Axis) SRVO-024 — Move Error Excess (Group / Axis) SRVO-043 — DCAL Alarm - Discharge Alarm SRVO-045 — HCAL Alarm - High Current SRVO-046 — OVC Alarm - Overcurrent (Average)
Same family: this code belongs to the Servo & drive alarms family - the page collects all Servo & drive-family codes we have handled, with the common inspection order and spares.
Other brands: see our KUKA, ABB, Yaskawa and Universal Robots field-fix libraries — or the full 10-brand hub.

Frequently asked questions

QWhat does the FANUC srvo-044 alarm mean?

The DC link voltage inside the amplifier exceeded the upper limit. This is a routine repair in our workshop for FANUC R-30iA / R-30iB / R-30iB Plus systems, and we normally pin it down during the first site check. FANUC srvo-044 sits in the servo & drive family; on our work orders the highest-frequency trigger for this code is "Incoming power voltage too high or transformer tap set wrong".

QCan I clear a FANUC srvo-044 alarm myself?

Whether FANUC srvo-044 clears on its own depends on the outcome of "Measure incoming 3-phase voltage and check transformer tap settings". Finish the flow with "If voltage is normal and alarm persists, the amplifier detection circuit is likely faulty - replace amp" to confirm FANUC srvo-044 - do not skip it. If that step is clean, the second most frequent cause on FANUC srvo-044 is "Regenerative energy not discharged (see SRVO-043)". After clearing FANUC srvo-044, watch it for one shift. A second trip means stop and let an engineer arrive with the right test gear for live servo circuits and rotating parts.

QFor servo alarms like FANUC srvo-044, how do you tell motor from drive?

The commonest causes we see on FANUC srvo-044 are "Incoming power voltage too high or transformer tap set wrong, Regenerative energy not discharged (see SRVO-043), Amplifier internal voltage detection fault", so we stock the van against those. For FANUC srvo-044 specifically, we bring the scope and meter; motors and drives are stocked by type, and most cases are measured before parts are ordered. For FANUC srvo-044, on servo alarms we specifically avoid misjudgement: waveform first, parts second, so customers skip needless swaps. Before we roll, tell us what FANUC srvo-044 shows on the iPendant ALARM screen (SRVO / MOTN / SYST / INTF prefixes) together with the amplifier's 7-segment status code and what the machine was doing - phone or video triage is free.

This page on FANUC srvo-044 was compiled from actual repair records of the Henghuan Robotics repair team. Alarm notes are our own summary for troubleshooting reference only and may vary with controller and software version — please consult FANUC documentation or contact us if in doubt. Henghuan is an independent service provider, not affiliated with or endorsed by FANUC.