Precision Zone Expertly Repairs Drives-AC Servo Mitsubishi MR-J2-_CT

Here at Precision Zone, one of our specialties is the repair services of Mitsubishi Servo units. One series that we often work on is the MR-J2-CT series.

The MR-J2-CT drive is a Mitsubishi auxiliary axis servo drive unit that contains an indexing function designed into the unit. This drive is designed for use with high-speed serial bus connection to the control. Running on an input 3-phase source of 200V AC, the MR-J2-CT unit has 8 different variations for output ratings. Ranging from 100W to 3kW, the MR-J2 is a versatile drive, capable of high-speed NC communication and efficient performance. With a strong emphasis on its absolute position detection system, this drive makes a perfect auxiliary servo drive.

When assessing the functionality of a drive, our repair team conducts a four-step check:

    1. Visual Overview
    2. Static Test
    3. Checks Under Power
    4. Alarm Codes Verification

This overview is Precision Zone’s basic troubleshooting process. Once our repair team starts on the job, we use specialized and customized testing fixtures, Huntron trackers, signal generators, oscilloscopes, milli and megaohm meters, as well as any other necessary tools we have available to assure quality repair work. Most importantly, every repair is fully tested in our custom-built simulators under load with a motor to replicate real-life working environment.

Precision Zone goes as far as using heating chambers and overnight dynamic testing, when applicable, to guarantee performance of the repaired product when it arrives back with the customer.

Repair Process for Mitsubishi MR-J2-CT AC Servo Drives

Visual Overview

When conducting a visual check, the technician inspects the drive for any mechanical damage to the drive itself and any printed circuit boards (PCB). The technician then proceeds to verify connections are tight and correct inside the drive and there are no loose screws, wires or debris. Additionally, the unit is checked for any burn marks on the components, PCBs or chassis. During the visual inspection, excessive dirt on cooling components is noted as well as the functionality of the heat sink.

Basic Static Check

Input Module Testing

The input modules on these units can be tested by use of a digital multimeter with diode checking capabilities. Upon removing the cover, all of these terminals can be located along the terminal strip found within the unit.

Positive Lead Negative Lead Reading
L1 'P' Terminal 0.2V - 0.7V
L2 'P' Terminal 0.2V - 0.7V
L3 'P' Terminal 0.2V - 0.7V
'N' Terminal L1 0.2V - 0.7V
'N' Terminal L2 0.2V - 0.7V
'N' Terminal L3 0.2V - 0.7V

Output Module Testing

Using the same type of test as above, the output modules can be checked as well. Our technicians are also equipped with huntron devices further verify their integrity.

Positive Lead Negative Lead Reading
U 'P' Terminal 0.2V - 0.7V
V 'P' Terminal 0.2V - 0.7V
W 'P' Terminal 0.2V - 0.7V
'N' Terminal U 0.2V - 0.7V
'N' Terminal V 0.2V - 0.7V
'N' Terminal W 0.2V - 0.7V

Common Alarms for the Mitsubishi MR-J2-CT Servo Drive Units

Alarm Code Description Quick Checks
S1 11 PCB Error
  • Ensure that all connections are correct
  • Check that all PCBs are seated correctly
  • Cycle Power
S1 25 Absolute Position Lost
  • Check backup battery for proper voltage
  • Reset absolute positioning according to machine and drive manuals
  • Check feedback for connection issues or problems with functionality
S3 10 Under Voltage
  • Check incoming 3 phase voltage
  • Voltage should be properly rated and balanced within 5% of each other
  • Check connections
  • Check for damage to the unit or short circuits on the output
S3, 50, 51 Overload
  • Check output for short circuits and ground faults
  • Check that motor is not overloaded
  • Check motor insulation
  • Verify connections

This list of checks for certain alarms is primarily a good starting point and if any further troubleshooting or technical support is needed feel free to contact us via phone or email to get in touch with our experienced tech support team.

Precision Zone offers free technical support on any component that you may be having issues with. We understand that when your machine goes down, your business stops. That is why our number one goal is to provide you with the best service possible so that you can get back up and running immediately. FFor any further product information or troubleshooting assistance is needed, please contact us via phone at 800-551-4420 or email us.

Precision Zone Repair Benefits for Mitsubishi MR-S2 Servo Drive Units

  • Free quotes and evaluations by our expert technicians include:
  • 12-Month Warranty on Our Parts and Labor
  • Decades of Industry Experience
  • Exchange Options
  • Rush Service Options

Contact Us To Start Your Repair Today!


Recently Repaired Products

Mitsubishi MR-J2-200CT image MR-J2-200CT is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Cooling Fans
Drive Type: MR-J2 AC Servo Drive
Rated Capacity: 2.0kW
Series: CT

Mitsubishi MR-J2-60CT image MR-J2-60CT is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Output Transistors/SCRs
Drive Type: MR-J2 AC Servo Drive
Rated Capacity: 600W
Series: CT

Mitsubishi MR-J2-100CT image MR-J2-100CT is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s)
Drive Type: MR-J2 AC Servo Drive
Rated Capacity: 1.0kW
Series: CT

Mitsubishi MR-J2-40CT image MR-J2-40CT is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s)
Drive Type: MR-J2 AC Servo Drive
Rated Capacity: 400W
Series: CT