What the 0x000039 alarm means

A joint brake failed to release or failed its self-test; the joint is locked to prevent the arm dropping. This is one of the faults our repair team handles on JAKA Zu / JAKA Pro cobots (APP) systems — the cause is usually identifiable within the first on-site inspection.

Most common causes

  • Brake power supply or wiring fault
  • Brake worn from age or excessive E-stop usage
  • Joint module internal fault
  • Wrong brake parameter after a module swap
Field note: the first item on this list is what we find most often on real machines. Check it before you go deeper.

Step-by-step field fix

  1. Do not force the joint — support the arm first
  2. Check brake supply voltage at the joint
  3. Power-cycle and listen for the brake click on enable
  4. Verify parameters after any module replacement
  5. Replace the joint module if the brake does not release
Safety first: never bypass safety circuits or force contactors closed. If the alarm involves E-stop chains, brakes or drive power, and you are not a trained robot technician, contact a professional — wrong moves here can cost you a robot or an injury.

Still stuck? Get an engineer on the phone — right now

Tell us the alarm code, the robot model and what was happening when the alarm came up. Our engineers run these diagnostics every day, and remote diagnosis by phone or video call is free.

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Hotline: +86-20-39029800 · WhatsApp: +86-188-1886-2860

Related Brakes alarms

0x000030 — Controller Temperature Too High 0x000031 — Bus Voltage Abnormal 0x000032 — Motor Overcurrent 0x000033 — Encoder Fault 0x000034 — Motor Overtemperature 0x000035 — Collision Detected
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 0x000039 alarm mean?

A joint brake failed to release or failed its self-test; the joint is locked to prevent the arm dropping. In field practice it belongs to the brakes family of faults.

QCan I clear a JAKA 0x000039 alarm myself?

Sometimes. Work through the step-by-step checks on this page — the first listed cause is what we find most often in the field. If the alarm returns after two attempts, or the fault involves power, brakes or safety circuits, stop and call a qualified robot service engineer.

QHow fast can a Henghuan engineer help?

On-site response in the Pearl River Delta within 30 minutes to 3 hours, across mainland China in 1-3 business days, and worldwide within 2-5 business days. Remote diagnosis by phone/WhatsApp/video is available immediately.

Written by the Henghuan Robotics repair team from field service experience. Alarm descriptions are our own summary for troubleshooting reference and may vary by controller and software version — when in doubt, check your JAKA documentation or contact us. Henghuan is an independent service provider, not affiliated with or endorsed by JAKA.