16.06.2025 by Viktor Siebert
Emergency in Stuttgart – Production Halt Due to MDS-D-V3-202020 (MDSDV3-202020)
Just a few days ago, we received an urgent call from Stuttgart. A long-standing customer – a metal processing company operating high-precision CNC turning machines – had come to a standstill. The reason: the Mitsubishi MDS-D-V3-202020 Servo Drive Unit suddenly stopped responding. Without warning, right in the middle of an important series production for the automotive industry.
The machine could still be started, but the screen only displayed multiple error messages from the drive unit.
Since it was a long holiday weekend, the machine manufacturer was unable to provide timely support. With many manufacturers currently facing a shortage of skilled personnel, this often ends up at the customers’ expense.
Initial Diagnosis – What Caused the Failure?
The unit was immediately shipped to us – express courier, well packaged, and accompanied by all relevant information. Upon arrival at our lab, we began with our standard visual inspection.
What stood out right away: slight burn marks on the underside and discoloration in the power module area – a typical sign of thermal overload or defective IGBT modules.
In the second step, we carried out our systematic fault analysis using high-frequency measurement, insulation testing, and signal input comparisons.
The Real Cause – More Than Just a “Defective Module”
What we discovered was more than just a worn-out power stage:
- The IGBT module was indeed burned out.
- A nearby capacitor had exploded – presumably due to a voltage spike.
- And to make matters worse, the internal gate driver chip had also been affected.
Precision Repair at the Highest Level
Our technicians opted for a complete overhaul of the power stage, including:
- Replacement of the IGBT module
- Renewal of all thermally stressed components in the surrounding area
- Replacement of all driver chips
- Cleaning and coating of the PCB for long-term stability
- Replacement of the cooling fans
In parallel, the internal heat sink was cleaned and the thermal paste replaced to prevent future overheating.
Final Testing and Express Return
After the successful repair, the unit underwent our multi-stage final inspection on our CNC simulation stand. The device passed all functional tests without any anomalies.
Just 48 hours after arrival, the MDS-D-V3-202020 unit – and a satisfied smile – left our facility via overnight express back to the customer.
Customer Feedback – “We’re Back in Production!”
The day after delivery, we received the following message from the customer:
“The machine is running perfectly again – your work saved us from a massive production loss. Thank you for the fast and professional support!”
To mentioned Mitsubishi Drive: Mitsubishi MDS-D-V3-202020 (MDSDV3-202020) Servo Drive Unit
More details about our Mitsubishi repair services can be found here:
Mitsubishi drive Repair by Industrypart
📞 Feel free to contact us with any questions about your Mitsubishi drive technology.
Our expert team is happy to help!
Device Description and Technical Data
Device Specifications
| Specification | Value |
|---|
| Model | MDS-D-V3-202020 |
| DC Bus Input Voltage | DC 270–311 V |
| Input Current | 21 A |
| AC Supply Voltage | 1PH / 3PH 200–230 V, 50/60 Hz |
| Output Voltage | 3 × 155 V, 0–240 Hz |
| Output Current | 3 × 4.6 A (for each axis, 3-axis module) |
| Number of Axes | 3 |
| Manufacturer | Mitsubishi Electric Corporation, Japan |
| Standard Compliance | EN50178 |
| Software Version | IB-1500010 |
| Hardware Version | Ver. G |
| Weight (approx.) | Approx. 5.5–6.5 kg (based on similar units) |
Operating Environment & System Integration
| Condition | Value |
|---|
| Operating Temperature | 0 to +55 °C (no freezing) |
| Storage Temperature | –15 to +70 °C (no freezing) |
| Humidity (Operation) | Max. 90% RH (non-condensing) |
| Humidity (Storage) | Max. 90% RH (non-condensing) |
| Altitude | Max. 1000 m above sea level (operation) |
| Installation | Indoors only, no corrosive gases, no conductive dust |
Used in combination with:
- Mitsubishi HF-, HP-, HF-KP-series servo motors
- MDS-D-CV power supply units
- Controlled by Mitsubishi CNC
- Communication via SSCNET optical interface
Functional Description
The MDS-D-V3-202020 is a three-axis servo drive unit designed for high-precision CNC systems. Key features:
- Precise position, speed, and torque control
- Built-in protection functions against overcurrent, overvoltage, and thermal overload
- Optical SSCNET communication with CNC controller
- Optional connections for brake resistors, fans, and temperature monitoring
Typical applications include multi-axis machining centers, turning machines, and high-speed automation systems.
Alarms & Troubleshooting
Alarm table excerpt with description and reset methods
| Alarm No. | Name | Description | Reset | Remedy |
|---|
| 10 | Insufficient Voltage | DC bus voltage too low | PR | Check mains voltage, possibly replace contactor |
| 13 | Software Processing Error | Internal processing timeout error | PR | Check environment, replace unit if needed |
| 16 | Initial Magnetic Pole Detection Error | Pole position not detected properly at servo ON | PR | Check SV028/SP118, redo pole detection |
| 17 | A/D Converter Error | Feedback current conversion error | PR | Replace drive, check ambient conditions |
| 30 | Over-Regeneration | Regenerative resistor overloaded | PR | Inspect braking circuit |
| 33 | Overvoltage | Bus voltage exceeded limits | PR | Check PSU and DC-Link |
| 45 | Fan Stop | Fan stopped or failed | PR | Clean or replace fan |
| 50 | Overload 1 | Motor or drive overloaded | NR | Reduce load, check mechanical axis |
| 73 | Over-Regeneration (Power Supply Alarm) | Regeneration exceeded 100%, wait 15 mins before reset | NR | Wait 15 minutes with power on, then reset |
