28.04.2025 by Viktor Siebert

Repair Completed

A two-axis drive module from Mitsubishi, model MDS-B-V2-2020, has just left our repair workshop.

Work Performed

Preventive maintenance was carried out, including the following tasks:

• Preventive overhaul with replacement of all necessary defective and worn parts.
• Intensive cleaning.
• Comprehensive final and load tests at our test benches.
• Parameter adjustment or restoration of parameters.
• Completion of documentation and checklists.

Support for Fault Analysis

With this contribution, we aim to support fault analysis.

What to Look Out For?

What should you pay attention to during fault analysis of such modules? These devices frequently fail at higher operating temperatures due to overheating. Additionally, motors may start jerking. Both issues can easily be localized directly on the device. Overheating is indicated by an alarm display on the device—for example, the code “3b” indicates overheating at the transistor module. In most cases, the power output stage of the drive module is affected. We strongly advise against continuing operation, as the transistor module could eventually burn out, rendering the entire device irreparable.

Diagnosing Motor Vibrations

If axis motors vibrate, there is often a defect in the drive module. Since two motors are installed, you should swap them temporarily to test. If the issue moves to the other axis, the motor is defective. If the issue remains at the original connection, it usually indicates a defect in the power output stage of the module, which should be refurbished.

Additional Fault Sources and Troubleshooting

There are other potential faults and analyses. A detailed troubleshooting guide can be downloaded here: Mitsubishi Error List PDF

Specific Repair Case

In a particular repair case, a customer approached us about a recurring issue he had been experiencing for some time, especially during summer. The exact problem was unclear because multiple modules in the machine displayed different indicators, creating confusion. Anyone familiar with Mitsubishi modules knows each module runs through various indicators upon startup, which can cause significant confusion during fault conditions. Unfortunately, the issue did not occur whenever external service companies came to inspect the equipment, though it appeared intermittently during summer and never during winter.

Our Approach

The customer found us coincidentally while searching online for parts for another machine and decided to inquire with us directly. We were familiar with the problem, and after our colleagues asked targeted questions, the customer was convinced to send the device to us. The repair took only four days.

Fault Reproduction and Quality

In such cases, it is often debated whether to reproduce the fault to ensure accuracy. Many competitors immediately provide an offer, assuming the issue will be resolved through parts replacement during overhaul. Why should we investigate further? Our philosophy differs: we attempt to reproduce the fault explicitly, as we have developed extensive test equipment and continuously invest in the quality of our services. These faults can often be reproduced if one knows how, though admittedly not always.

Customer Satisfaction

We offered the customer targeted fault testing, which he gladly accepted. By systematically heating, cooling, and performing specialized load tests, we reproduced the fault. The device has since been operating without issues, providing the customer with a sense of security and satisfaction.

Our Service for You

If you would like your equipment tested, our team is available with the necessary time and equipment!

Overview: Price and Delivery Time for Mitsubishi Servo Amplifier MDS-B-V2-2020

Technical Specifications

According to available product information, the MDS-B-V2-2020 has the following characteristics:

• Axes: 2 independent axes
• Rated Current per Axis: 13 A
• Input Voltage: DC 270–311 V, 28 A
• Input Voltage AC: 200/200-230 V, 50/60 Hz, 0.2 A
• Cooling: Air cooling with cooling fins

Function and Application

The MDS-B-V2-2020 is used in CNC machines to precisely control axis movements. It receives position and speed commands from the CNC controller and adjusts the current to the servo motors accordingly. Due to its capability of controlling two axes simultaneously, the MDS-B-V2-2020 is particularly suited for machines requiring compact and efficient drive solutions.

For more information about our Mitsubishi repairs, please click here.

📞 Feel free to contact us if you have any questions regarding your Mitsubishi drive technology. Our experienced team is always ready to provide you with expert advice and support.