Precision Zone Expertly Repairs Drives-AC Spindle Mitsubishi MDS-(A)(B)-CV Converter/Power Supply

Here at Precision Zone, one of our specialties is the repair services of Mitsubishi MDS Power Supplies. One series that we often work on is the MDS-A/B-CV series.

In traditional Mitsubishi setups, the converter unit had been built into each individual unit in the signal chain. The MDS-A/B-CV series did away with that and introduced a more modular design approach. For this system, the converter is a standalone unit that feeds all corresponding servo and spindle drives. Also new to the design is the use of an IPM (intelligent power module) that helps reduce heat generation. Taking 3 phase input, the MDS-A/B-CV units distribute control power and a shared bus line across the front of the units.

When assessing the functionality of a converter unit such as this, our technician's employ a basic four step troubleshooting process:

    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 Fanuc Alpha Series AC Spindle 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 (L+) 0.34V-0.37V
L2 'P' Terminal (L+) 0.34V-0.37V
L3 'P' Terminal (L+) 0.34V-0.37V
'N' Terminal (L-) L1 0.34V-0.37V
'N' Terminal (L-) L2 0.34V-0.37V
'N' Terminal (L-) L3 0.34V-0.37V

Mitsubishi Converter Units Common Alarms

Alarm Code Description Quick Checks
1 Overcurrent in IPM
  • Check for any alarms with any servos or spindle drives and troubleshoot accordingly
  • Measure incoming voltage; ensure it is in the proper range
  • Check DC bus voltage
9 Ground Fault
  • Check resistance between incoming terminals and bus
  • Disconnect motors from servo and spindle drives and apply power. If alarm clears, meg motors
  • Check IPM
C Main Circuit Error
  • Cycle Power
  • Double check all connections and wiring
  • Reseat all connections on the front of the drive
E Memory Error
  • Cycle Power
  • Double check all connections and wiring
  • Check the potentiometers on the front of the unit
  • Double check parameters in the machine

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. For 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 Fanu AC Spindle Alpha Series

  • Free evaluation by expert technician includes:
    • Visual Inspection
    • Static Checks
    • Power Tests
    Free Job Estimate
  • 12-Month Warranty on Our Parts and Labor
  • Flat Price
  • Exchange Options
  • Rush Service Options

Contact Us To Start Your Repair Today!


Recently Repaired Products

Mitsubishi MDS-A-CV-260 image MDS-A-CV-260 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Cooling Fans
Unit Type: MDS-A-CV AC Converter/Power Supply for MDS-A Systems
Compliance Specifications: Standard
Power Supply Capacity: 26.0kW

Mitsubishi MDS-B-CV-185 image MDS-B-CV-185 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s), Not Repairable Recommend Replacement, Physical Damage to the Drive, Wrong/corrupted parameters
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: Standard
Power Supply Capacity: 18.5kW

Mitsubishi MDS-B-CV-110 image MDS-B-CV-110 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Cooling Fans
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: Standard
Power Supply Capacity: 11.0kW

Mitsubishi MDS-B-CVE-150 image MDS-B-CVE-150 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s), Bad Cooling Fans, Bad Gate Section/Board, Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces)
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: UL/c-UL Standards
Power Supply Capacity: 15.0kW

Mitsubishi MDS-B-CV-220 image MDS-B-CV-220 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s)
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: Standard
Power Supply Capacity: 22.0kW

Mitsubishi MDS-A-CV-300 image MDS-A-CV-300 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Board Replacement Required, Bad Circuit Board Component(s), Bad Cooling Fans, Bad Gate Section/Board, Bad Magnetic Contactor, Relay, Bad Power Board, Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces), No Display
Unit Type: MDS-A-CV AC Converter/Power Supply for MDS-A Systems
Compliance Specifications: Standard
Power Supply Capacity: 30.0kW

Mitsubishi MDS-B-CV-300 image MDS-B-CV-300 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s), Bad Cooling Fans, Bad Gate Section/Board, Bad Power Section/Board, Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces), No Display
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: Standard
Power Supply Capacity: 30.0kW

Mitsubishi MDS-B-CVE-450 image MDS-B-CVE-450 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Cooling Fans, Bad Output Transistors/SCRs, No Display
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: UL/c-UL Standards
Power Supply Capacity: 45.0kW

Mitsubishi MDS-B-CVE-185 image MDS-B-CVE-185 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s), Bad Cooling Fans, Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces)
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: UL/c-UL Standards
Power Supply Capacity: 18.5kW

Mitsubishi MDS-A-CV-110 image MDS-A-CV-110 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Leaky Capacitors (Open, Corroded Traces), No Display
Unit Type: MDS-A-CV AC Converter/Power Supply for MDS-A Systems
Compliance Specifications: Standard
Power Supply Capacity: 11.0kW

Mitsubishi MDS-B-CV-55 image MDS-B-CV-55 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Cooling Fans, No Display
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: Standard
Power Supply Capacity: 5.5kW

Mitsubishi MDS-B-CV-75 image MDS-B-CV-75 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s), Bad Cooling Fans, Physical Damage to the Drive
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: Standard
Power Supply Capacity: 7.5kW

Mitsubishi MDS-B-CV-370 image MDS-B-CV-370 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Cooling Fans
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: Standard
Power Supply Capacity: 37.0kW

Mitsubishi MDS-B-CV-260 image MDS-B-CV-260 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Cooling Fans, Leaky Capacitors (Open, Corroded Traces)
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: Standard
Power Supply Capacity: 26.0kW

Mitsubishi MDS-B-CV-150 image MDS-B-CV-150 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Cooling Fans
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: Standard
Power Supply Capacity: 15.0kW

Mitsubishi MDS-A-CV-220 image MDS-A-CV-220 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s), Bad Cooling Fans, Bad Power Board, Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces)
Unit Type: MDS-A-CV AC Converter/Power Supply for MDS-A Systems
Compliance Specifications: Standard
Power Supply Capacity: 22.0kW

Mitsubishi MDS-B-CVE-260 image MDS-B-CVE-260 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s)
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: UL/c-UL Standards
Power Supply Capacity: 26.0kW

Mitsubishi MDS-A-CV-150 image MDS-A-CV-150 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Regen Section, Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces)
Unit Type: MDS-A-CV AC Converter/Power Supply for MDS-A Systems
Compliance Specifications: Standard
Power Supply Capacity: 15.0kW

Mitsubishi MDS-B-CVE-370 image MDS-B-CVE-370 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s)
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: UL/c-UL Standards
Power Supply Capacity: 37.0kW

Mitsubishi MDS-B-CV-37 image MDS-B-CV-37 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s)
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: Standard
Power Supply Capacity: 3.7kW

Mitsubishi MDS-A-CV-185 image MDS-A-CV-185 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Leaky Capacitors (Open, Corroded Traces)
Unit Type: MDS-A-CV AC Converter/Power Supply for MDS-A Systems
Compliance Specifications: Standard
Power Supply Capacity: 18.5kW

Mitsubishi MDS-B-CVE-300 image MDS-B-CVE-300 is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s), Bad Output Transistors/SCRs, Blown Circuit Board (Through Hole), Leaky Capacitors (Open, Corroded Traces)
Unit Type: MDS-B-CV AC Converter/Power Supply for MDS-B Systems
Compliance Specifications: UL/c-UL Standards
Power Supply Capacity: 30.0kW