A customer approached us with a Fanuc Power Supply Module A06B-6087-H130, which displayed alarm 01 immediately at power-up. For him, a lot was at stake: the machine was a central part of his production, and every hour of downtime meant lost orders. FANUC itself offered an exchange module for about €7,000, requiring the defective unit to be returned. The customer hesitated, saying: “My machine is important, but I prefer to wait two or three days for a repair rather than spend unnecessary money and have the old module scrapped.”

Fault symptoms and initial diagnosis

Alarm 01 means the power module (IPM Intelligent Power Module) detected overload, overcurrent or control voltage drop. When the unit was opened, several issues became visible:

• Cooling fan sluggish and intermittently failing
• Dust and oil contamination inside the cooling channel
• Clogged heatsink with reduced thermal capacity
• IPM showed unstable measurement values

Disassembly and cleaning

The module was fully disassembled. Dust, conductive particles and oil deposits were removed using compressed air, brushes and solvents. The heatsink was cleaned to restore full cooling efficiency.

Preventive replacement

To ensure long-term reliability, we replaced critical parts:

• New fan unit installed
• DC-link capacitors checked, suspicious ones replaced
• Connectors cleaned and coated with protective lacquer
• IPM module replaced with an original FANUC part

Test bench procedure

After reassembly, the unit was tested under realistic conditions:

1. Initial check without load control voltages and signals verified
2. Load simulation device operated under various load levels
3. Thermal stress tests monitored semiconductor temperatures and fan currents
4. Signal monitoring oscilloscope analysis of switching behavior and DC-link stability
5. Long-term test several hours of continuous operation to ensure stability

All steps were documented in a detailed checklist and test report.

Risk without repair

If the customer had continued operation, the fan would have failed completely. The IPM would have overheated, possibly damaging not only the PSM but also connected servo and spindle amplifiers, causing extensive collateral damage and five-figure costs.

Result and customer benefit

The repaired module was reinstalled and the machine ran without error. The customer saved around 80% of the costs, extended the lifetime of his equipment and prevented a cascade of failures.
He also decided to introduce preventive maintenance for his other modules, shifting from reactive breakdown repair to proactive reliability.

To mentioned Fanuc Drive: Fanuc Power Supply Module A06B-6087-H130

More details about our Fanuc repair services can be found here:
Fanuc drive Repair by Industrypart

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Device Specifications:

Application & Compatible Devices

• Typical machines: CNC machining centers, lathes, grinders, machine tools with FANUC control.
• Compatible controls: FANUC Series 0, 15, 16, 18, 20, 21, Power Mate.
• Compatible modules:
  • FANUC α-Servo Amplifier Module (SVM)
  • FANUC α-Spindle Amplifier Module (SPM)
• Use cases: Provides DC link power supply for servo and spindle amplifiers.

Functional Description

The Power Supply Module A06B-6087-H130 converts incoming AC voltage into a stable DC link (283–325 V). This DC power feeds servo and spindle amplifiers.
Features:

• Integrated protection against overcurrent, overload, undervoltage.
• LED indicators for operation and alarm states.
• Safety shutdown (MCC) in case of critical faults.
• Cooling control with fan monitoring and alarm.

Alarm Messages & Troubleshooting

Components