- Quick Quote
- +86 18295370559
- +86 18295370559
- Email: info@cncfixtech.com
A FANUC power supply alarm is one of the most common issues that can cause CNC machines to stop unexpectedly.FANUC power supply modules are the heart of the CNC system, providing stable DC power for servo and spindle amplifiers. When a fault occurs, it can cause machine downtime and system instability. Understanding the causes and repair methods of these power supply alarms can help you diagnose problems more effectively and restore production quickly.
At CNCFixtech, our technicians specialize in FANUC power supply repair, covering αi, βi various series units. In this guide, we summarize the most frequent FANUC power supply alarms, explain their causes, and share practical repair solutions.
| Alarm Code | Fault Description | Possible Cause | Recommended Action |
|---|---|---|---|
| PIL Light OFF | Power indicator not illuminated after power ON | 1. No AC input power 2. Fault in power circuit | 1. Check AC 200V input at CX1 (R, S terminals) 2. Inspect internal circuit and repair if necessary |
| MCC Not Engaged | Main contactor fails to close | 1. Emergency stop not released 2. Terminal plug connection faulty 3. MCC contactor damaged 4. Power line broken | 1. Release E-stop and test circuit 2. Check plug K9 (JX1B) connection to JXB1 on SVM/SPM 3. Replace damaged MCC contactor or wire |
| STATUS LED ON, Alarm Displayed | Alarm code appears on 7-segment display | Internal fault in power supply module | Check alarm number and LED status, analyze fault based on alarm code |
| Alarm Code “01” | IPM (Intelligent Power Module) error in main circuit | 1. IGBT or IPM module failure 2. AC reactor degraded | 1. Replace IGBT or IPM after verifying cause 2. Replace AC reactor |
| Alarm Code “02” | Cooling fan not rotating | Fan motor failure | Repair or replace fan motor |
| Alarm Code “03” | Heatsink temperature rise abnormal | 1. Cooling fan fault 2. Poor cabinet ventilation 3. Overload | 1. Replace fan motor 2. Clean cooling system 3. Check for overload condition |
| Alarm Code “04” | DC bus voltage too low | 1. Power interruption 2. Low input voltage 3. Incorrect shutdown operation | Check power stability and follow proper shutdown procedures |
| Alarm Code “05” | DC charging not completed in time | 1. DC short circuit 2. Faulty charging resistor | 1. Inspect circuit and replace damaged parts 2. Replace resistor or line board |
| Alarm Code “06” | Abnormal input power | Input phase missing | Test power input circuit, replace faulty components |
| Alarm Code “07” | DC voltage too high | 1. High AC impedance 2. Regeneration circuit fault 3. IPM/IGBT failure | 1. Check impedance 2. Verify IR/IS terminals for overvoltage 3. Replace IPM/IGBT after confirming cause |
Read our detailed repair story:
FANUC A06B-6140-H011 Power Supply Alarm 7 Repair Case
In this case, our engineers successfully diagnosed and repaired an Alarm 7 (DC voltage rise abnormal) issue on a FANUC A06B-6140-H011 power module. The root cause was a regeneration circuit fault combined with an IPM failure. Through component-level analysis and replacement, the module was restored to full working condition — demonstrating our expertise in FANUC power supply repair and testing.
For more real repair cases and technical insights, check out our YouTube channel
— we regularly share FANUC power supply troubleshooting and repair videos.
FANUC power supply alarms can indicate anything from minor circuit issues to serious module failures. With proper diagnosis and professional repair, most of these problems can be solved efficiently.
If your FANUC Power Supply Module such as A06B-6110-H026 (αiPS26) or similar model shows any of the above alarms, contact CNCFixtech — we provide expert repair and replacement services for all FANUC power supplies.
Yes. Our engineers can replace and test the internal IPM or IGBT module, ensuring your unit works like new.
Most repairs take 3–5 working days, depending on component availability and fault type.
Yes, every power supply is fully tested under load before shipping to ensure reliable performance.
Absolutely. We provide 3-month warranty for used, 6-month for refurbished, and 12-month for new units. Extended warranty options are available.
How we process your repair requirements
Get in touch with us and provide as much detail as possible about the issue you are experiencing.
Our professional repair team will help assess the severity of the problem and the possibility of repair.
The customer sends or delivers the servo drive to our company. We register it in our system and prepare it for further inspection.
Our engineers diagnose the fault points of the servo drive and provide a detailed inspection report, including the final repair cost and estimated repair time.
We provide the repair quote to the customer and wait for their confirmation. If the customer agrees to the quote, we proceed with the repair.
Upon customer approval, we carry out the necessary repairs. After repairs are completed, we perform tests with the motor and conduct aging tests to ensure the servo drive operates reliably under various conditions. Once the testing is successful, we register the drive for delivery.
The customer completes the payment, and we deliver the repaired servo drive to the customer.
We provide attentive follow-up service to ensure customer satisfaction and address any further needs.
