Free tool · Mitsubishi MR-J4 · MR-J3 · MR-J2S · Updated November 2026
Mitsubishi servo alarm lookup: MR-J4, MR-J3 and MR-J2S alarm and warning codes
Choose the amplifier series, type the number shown on the display, and the lookup gives the alarm name and, for MR-J3 and MR-J2S, the cause in brief. The data comes from the Mitsubishi Electric instruction manuals. Star Automations is an independent repairer, not a Mitsubishi Electric authorised service provider.
Find an alarm
The lookup runs in your browser and stores nothing.
Questions
Which alarm lists does the lookup use?
The troubleshooting chapters of the Mitsubishi Electric MR-J4, MR-J3-A and MR-J2S-A instruction manuals. Numbers differ between series, so choose the series on the amplifier label first.
Why does the lookup show a guide for some alarms only?
We have written detailed guides for the most common alarms, such as 10, 16, 20, 25, 30, 31, 32, 33, 45, 46, 50, 51 and 52. The guides were written for MR-J4, so causes can differ on MR-J3 and MR-J2S.
Does an alarm always mean the servo motor is faulty?
No. Many alarms come from the supply, the regenerative resistor, the cable or the encoder. Check these before replacing the motor or the amplifier.
Does the lookup store the number I type?
No. It runs in your browser. Nothing is sent unless you press the WhatsApp button.
Can Star Automations repair the amplifier?
Yes. We repair Mitsubishi MELSERVO amplifiers, servo motors and encoders. We are an independent repairer, not an authorised service provider of Mitsubishi Electric.
About the author
S. Suresh, Founder and CEO of Star Automations. More than 25 years in industrial electronics repair, with servo motor and drive repair as the main focus since 1998. Last updated: .
Send the alarm number and amplifier model.
WhatsApp a photo of the amplifier label and the display to +91 97866 22233, or email info@starautomations.com.