Precision Zone Expertly Repairs Drives-AC Servo Mitsubishi MDS-B-SVJ2

Here at Precision Zone, one of our specialties is the repair services of Mitsubishi MDS units. One series that we often work on is the MDS-B-SVJ2 series.

Mitsubishi's MDS series of servo drives are a modular and efficient series of servo and spindle drives. These units are similar in style to the MR-J2 and MR-J2S servo drives. Ranging in size from 0.1kW to 2.0kW, this series is designed for lower output wattage and high precision. Allowing one and two axis offerings, the MDS-B-SVJ2 series of drives offer a slim, compact package without sacrificing performance.

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-S2 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
U (L1) 'P' Terminal 0.31V - 0.33V
V (L2) 'P' Terminal 0.31V - 0.33V
W (L3) 'P' Terminal 0.31V - 0.33V
'N' Terminal U (L1) 0.31V - 0.33V
'N' Terminal V (L2) 0.31V - 0.33V
'N' Terminal W (L3) 0.31V - 0.33V

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 0.31V - 0.33V
V 'P' Terminal 0.31V - 0.33V
W 'P' Terminal 0.31V - 0.33V
'N' Terminal U 0.31V - 0.33V
'N' Terminal V 0.31V - 0.33V
'N' Terminal W 0.31V - 0.33V

Common Alarms for the Mitsubishi MDS-B-SVJ2 Servo Drive Units

Alarm Code Description Quick Checks
10 Insufficient Volatage
  • Check incoming voltage to the drive. Make sure it is balanced and within proper rating
  • Check cabling; correct if necessary
  • Check for failed relay
  • Check for ground faults
25 Absolute Position in Detector was Lost
  • Check battery voltage - a drop in voltage can cause this
  • Check that the battery is connected
  • Check detector cable was disconnected
30 Over Regeneration
  • Check regenerative resistor
  • Check parameter SV036
  • Check the power supply voltage
  • Increase deceleration time
3A Over Current
  • Check motor or wire for ground fault
  • Check input/output terminals to ground for leakage
  • Check output transistors
  • Lower compensation gain

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 MDS-B-SVJ2-07 image MDS-B-SVJ2-07 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s)
Drive Series: MDS-B-SVJ2 200-230V
Capacity: 0.7kW

Mitsubishi MDS-B-SVJ2-20 image MDS-B-SVJ2-20 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Cooling Fans, Leaky Capacitors (Open, Corroded Traces), Bad Output Transistors/SCRs
Drive Series: MDS-B-SVJ2 200-230V
Capacity: 2.0kW

Mitsubishi MDS-B-SVJ2-10 image MDS-B-SVJ2-10 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Output Transistors/SCRs, Bad Brake Transistor (Regen), Bad Capacitor(s), Bad Circuit Board Component(s)
Drive Series: MDS-B-SVJ2 200-230V
Capacity: 1.0kW

Mitsubishi MDS-B-SVJ2-04 image MDS-B-SVJ2-04 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s)
Drive Series: MDS-B-SVJ2 200-230V
Capacity: 0.4kW

Mitsubishi MDS-B-SVJ2-01 image MDS-B-SVJ2-01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Output Transistors/SCRs
Drive Series: MDS-B-SVJ2 200-230V
Capacity: 0.1kW