A Mitsubishi MR-J2S-100B4 arrived at industrypart with a customer report of E9. During incoming inspection, our workshop recorded a DC bus voltage of 182 V and assessed it as too low. A defective HCPL component was also identified. This report describes the diagnosis, the overhaul performed and the documented inspection results.

Technical data and classification

These are device ratings, not output measurements taken during this repair. The unaltered original rating-plate photograph is the reference for technical data.

Machine application and interchangeability

The MR-J2S-100B4 is a 400 V class model. Mitsubishi lists the HC-SFS1024 motor in the relevant supplementary manual. This is a manufacturer-listed pairing, not a statement about a motor connected during this order. The complete model, controller, parameters and machine configuration must be checked before replacement.

How the servo amplifier works

A servo amplifier supplies controlled electrical power to a servomotor. The supply, power circuit and signal processing must be considered together. For this unit, the overhaul addressed the documented electronic components and fan.

Components and documented work

Customer report and workshop findings

Understanding the E9 indication

The Mitsubishi MR-J2S-B manual associates E9 with a servo enable request while the main power circuit is off. This warning does not identify a specific failed component. The customer report must therefore be distinguished from the workshop findings.

In this case, the low DC bus voltage and the HCPL component identified as defective provided the concrete starting points for the repair. The E9 indication alone would not justify diagnosing a failed capacitor or cooling fan.

Selected warnings of the MR-J2S-B series

Only E9 was reported by the customer in this case. This overview distinguishes other warnings of the series. Diagnosis requires the appropriate manual and consideration of the exact unit variant.

Repair and inspection footage

We cleaned and overhauled the servo amplifier. The electrolytic capacitors, HCPL components and cooling fan were renewed. The work therefore covered the documented electronic components and the cooling system. An exact HCPL part number is not specified for this first order, so only the recorded component family is identified here.

A DC bus voltage of 602 V was recorded after the work. The display and fan were checked and assessed as OK. The alarm memory was cleared and the rotary switch was returned to its original position.

DC bus voltage is a value in the DC link and must be distinguished from the three-phase input voltage on the rating plate. The video briefly shows 601 V, while the written workshop record specifies 602 V. Each value is attributed to its respective source.

Preventive care and preparing a repair enquiry

Diagnosis should combine the reported indication, visible condition and recorded measurements. An alarm reset alone does not document a repair, and a clean appearance cannot replace electrical inspection. This report therefore focuses on the recorded findings and inspection values.

Clear ventilation paths, an intact housing and undamaged connections are useful inspection points. Abnormalities should be investigated by qualified personnel. This individual order does not establish fixed maintenance intervals or a specific service life.

For a repair enquiry, provide the complete model designation, a legible rating plate and the exact indication. Describe when the fault occurs and any work already carried out. This helps prepare the investigation.

Sources

Case sources: workshop documentation and original media from the first overhaul, repair order 107931-1, September 2026. Manufacturer references: Mitsubishi MR-J2S-B Instruction Manual SH(NA)030007-G, section 9.3, page 9-8; MR-J2S-A4/B4 Supplementary Instruction Manual SH(NA)030026-F, 400 V variant and motor combinations.

Repair video and photographs

The film combines photographs from this order with original footage of the workshop inspection. The German narration explains the incoming fault, the renewed components and the documented results.

Request a repair

Contact industrypart for current pricing and lead time for a Mitsubishi MR-J2S-100B4 repair. Include the full model designation and observed symptoms. Our team can assist with technical assessment and planning the repair.