What the 0x000031 alarm means

The DC bus voltage inside a joint module or the controller is outside the valid window — too high from regeneration or too low from a weak supply. We are very familiar with this alarm on JAKA Zu / JAKA Pro cobots (APP) systems — usually the first on-site inspection is enough to confirm the cause.

Most common causes

  • Incoming supply voltage out of range
  • Braking resistor path open (overvoltage case)
  • Loose power connectors (undervoltage case)
  • Power supply module aging
Field note: Our ticket data shows the first cause is by far the most common — start there to avoid dead ends.

Step-by-step field fix

  1. Measure the incoming AC/DC supply against the nameplate
  2. Check all power connectors for tightness
  3. Inspect the braking resistor and wiring
  4. Reduce deceleration rates and retry
  5. If voltage is stable, suspect the power module and contact service
Safety first: For JAKA 0x000031, this alarm family involves the DC bus, which sits at several hundred volts and stays charged for minutes after power-off - touching terminals is a shock hazard. The self-serviceable action is Measure the incoming AC/DC supply against the nameplate; anything past that falls under the DC bus and power stage and needs a certified engineer. On JAKA 0x000031: checking incoming voltage at the disconnect and looking at breakers and fuses is fine to do yourself; opening the cabinet to touch bus terminals or pulling power modules needs a qualified electrician.

How we diagnose drive alarms on site

JAKA 0x000031 belongs to the drive & power stage family. On JAKA 0x000031 the failing stage is joint-integrated drive modules on the JAKA collaborative robot cabinet - the fault sits on the energy chain: mains input, rectification, DC bus, braking resistor, inverter power devices and the drive board. We start reading JAKA 0x000031 at the pendant and app alarm pages; codes are hexadecimal with a 0x prefix.

The chain involved in JAKA 0x000031 runs: three-phase mains -> rectifier -> DC bus (bus capacitors) -> brake chopper / braking resistor -> inverter (IGBT) -> motor.

Bottom line up front: Incoming supply voltage out of range is the first suspect for JAKA 0x000031, but read it along the energy chain: Any link on this chain dropping voltage shows up at the end as a drive alarm, so order matters. We measure the mains first: more than 3% phase imbalance is enough to sag the bus under load, and plenty of bus over/under-voltage alarms are actually a grid problem wearing a robot costume. Mains fine, then the bus capacitors - bulged cases, weeping electrolyte or a lifted vent mean replacement; capacitance down 20% or more cannot hold the bus during braking. Last, the braking resistor: healthy values sit in the tens of ohms depending on rating, and an open or drifted resistor trips regenerative overvoltage directly.

Field notes on this page cover JAKA 0x000031 (Bus Voltage Abnormal); written by the Henghuan repair team, updated 2026-10-01.

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Related Drive & Power Stage alarms

0x000032 — Motor Overcurrent
Same family: this code belongs to the Drive & power stage alarms family - the page collects all Drive & power stage-family codes we have handled, with the common inspection order and spares.
Other brands: we also keep field-fix libraries for AUBO · ROKAE · Dobot and more — see the complete alarm code hub.

Frequently asked questions

QWhat does the JAKA 0x000031 alarm mean?

The DC bus voltage inside a joint module or the controller is outside the valid window — too high from regeneration or too low from a weak supply. We are very familiar with this alarm on JAKA Zu / JAKA Pro cobots (APP) systems — usually the first on-site inspection is enough to confirm the cause. JAKA 0x000031 sits in the drive & power stage family; on our work orders the highest-frequency trigger for this code is "Incoming supply voltage out of range".

QCan I clear a JAKA 0x000031 alarm myself?

Whether JAKA 0x000031 clears on its own depends on the outcome of "Measure the incoming AC/DC supply against the nameplate". Finish the flow with "If voltage is stable, suspect the power module and contact service" to confirm JAKA 0x000031 - do not skip it. If that step is clean, the second most frequent cause on JAKA 0x000031 is "Braking resistor path open (overvoltage case)". Two attempts and still there means stop: JAKA 0x000031 involves the DC bus and power stage, and running JAKA 0x000031 on can turn a repairable fault into a replacement.

QFor drive/power alarms like JAKA 0x000031, what spares do you bring on site?

The commonest causes we see on JAKA 0x000031 are "Incoming supply voltage out of range, Braking resistor path open (overvoltage case), Loose power connectors (undervoltage case)", so we stock the van against those. For JAKA 0x000031 specifically, we stock the van along the energy chain: braking resistors, bus capacitors, input fuses, drive-board supply parts and the common power modules for the brand. For JAKA 0x000031, drive alarms usually stop the whole line, so they sit at the front of our dispatch queue. Before we roll, tell us what JAKA 0x000031 shows on the pendant and app alarm pages; codes are hexadecimal with a 0x prefix and what the machine was doing - phone or video triage is free.

The content on JAKA 0x000031 was written by Henghuan Robotics service engineers from hands-on repair experience. Alarm descriptions are our own reference summary and may differ by controller or software version — defer to JAKA documentation, or contact us to confirm. Henghuan is an independent service provider with no affiliation or endorsement by JAKA.