14.07.2025 by Viktor Siebert

A long-standing customer approached us with an unusual issue: the Mitsubishi MDS-DH-V2-1010 servo drive unit in one of his machines would frequently fail to start when cold. It often took multiple attempts of powering the machine on and off until the device finally booted up and operated normally. This pattern continued for several months until the failures became more frequent. Eventually, the drive began shutting down randomly even during operation.

The Day of Total Failure

One day, the inevitable happened, the machine could no longer be started at all. The customer, who had previously only sent us Yaskawa modules and motors for repair, now asked if we could repair this Mitsubishi unit. He mentioned that the Mitsubishi systems had always run flawlessly while the machines were still under a service contract with the manufacturer. However, now that the warranty had expired, replacement parts had become prohibitively expensive. He was pleasantly surprised to learn that we also specialize in Mitsubishi drive technology. As is often the case, customers only become proactive once a bottleneck arises and that’s where we came in.

Transparency in pricing and high-quality work have always been crucial for this customer.

Damage Assessment and Root Cause

Upon arrival at our facility, the device was immediately inspected and analyzed. It was completely unresponsive. A visual inspection of the main board revealed a bulging and leaking electrolytic capacitor. A multimeter test in the affected area confirmed a short circuit to ground.

The leaking electrolyte had corroded nearby traces on the PCB, gradually increasing resistance until it ultimately caused a short. The capacitor was clearly the root cause of the poor startup behavior. Over time, the issue escalated and the internal power supply suffered collateral damage as well, with multiple power components burning out. What began as a minor fault evolved into a major system failure.

Repairs and Preventive Measures

The damaged capacitor was carefully removed, and surrounding PCB traces were cleaned and restored. The internal power supply was completely overhauled: several ICs, electrolytic capacitors, and power transistors were replaced. The entire unit was thoroughly inspected for further weaknesses, and all critical areas were reinforced or rebuilt as needed.

The entire assembly was then deep-cleaned and dried using controlled methods.

Long-Term Testing with Original Motor

After repairs were completed, the unit was extensively tested with a compatible Mitsubishi motor under real operating conditions. Multiple test programs were executed, including different load and runtime scenarios. The drive passed all tests without any issues.

Outcome: A Satisfied Customer and Valuable Insight

The customer was more than satisfied with the result: a cost-effective, professionally executed repair backed by full transparency and detailed diagnostics. For us, it was another example of how small defects (when left untreated) can lead to major failures. Thanks to our experience, precise analysis, and technical care, we not only restored functionality but also ensured long-term reliability.

To mentioned Mitsubishi Drive: Mitsubishi MDS-DH-V2-1010 Servo Drive

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 Yaskawa drive technology.
Our expert team is happy to help!

Technical Summary of the Unit

Parameter	Value
Type	MDS-DH-V2-1010
Input	1.8 A DC 513–648 V0.1 A 1PH 380–440 V, 50/60 Hz
Output	2.3 / 2.3 A, 3PH 0–240 Hz
Power	1.0 / 1.0 kW
Serial Number	J3AH6G04B7P
Certifications	TÜV, UL, CE, KCC
Weight	Not listed on the nameplate – approx. 2.5–3.5 kg according to type
Date of Manufacture	04/2012
Reference Manual	IB-1500875

Alarm Messages & Troubleshooting

Alarm No.	Name	Cause / Solution
10	Insufficient Voltage	DC bus voltage too low – check main input
11	Axis Selection Error	Incorrect rotary switch setting – verify switch position
23	Excessive Speed Error	Feedback deviation too high – check parameters (e.g. SP096, SP026)
25	Absolute Position Data Lost	Battery voltage too low or cable disconnected – replace battery, re-home axis
30	Over Regeneration	Regenerative resistor overloaded – check wiring and selection
32	Power Module Overcurrent	Short circuit or overcurrent – check load, cabling, motor
50/51	Overload 1 / Overload 2	Motor or amplifier overload – review load and acceleration settings
5D	Safety Observation: Door State Error	NC and Drive door status signals do not match – check wiring and input sequence

Components According to Assembly Overview (Table)

Component	Board Code / Description	Qty
Control Board	RM115A-22 or BC886A028G51	1
Power Board	RM162C-V2 or BC886A010G52 A	1
Power Module	BKO-NC1207 H84 or A2-DH-V2-1010	1