Fiber Laser Cutting Machine No Laser Output Troubleshooting Guide

When a fiber laser cutting machine suddenly stops emitting light during operation, but the power meter still displays normal values, it is essential to quickly identify the root cause. This guide outlines common fault scenarios and effective diagnostic methods to help restore normal operation.

Initial Check: Laser Source Output

First, verify whether the laser source is generating light internally:

• If light is present inside the laser source but no beam is emitted externally, the laser source may be damaged.

Common Fault Scenario 1: No Laser After Restart

If the machine operated normally the previous day but fails to emit laser after restarting:

Check Cooling System

• Inspect the chiller’s water return to ensure proper circulation.

• Confirm that cooling water flows smoothly through the laser source.

Observe Ammeter Status

• Ammeter normal: The laser source is likely damaged. Contact the manufacturer for repair or replacement.

• Ammeter abnormal: The laser power supply may have failed. Arrange for professional maintenance.

Quick Detection Methods

• Method 1: Place adhesive paper on the first reflecting lens and trigger laser emission. If no burn marks appear, the laser source is defective.

• Method 2: Temporarily short-circuit the PG terminal of the laser power supply to bypass water protection (for testing only). Note: Do not use this method for extended periods, as it may damage the laser source.

If No Cooling Water Circulates

• Check the laser power supply and press the red manual trigger button.

• If the laser emits, the water protection device may be faulty.

• Clean any blocked outlets and flush the water pipeline thoroughly.

Common Fault Scenario 2: Diagnose via Ammeter Current

• Press the laser emission button and observe the ammeter reading.

• If the current is below 5 mA, the laser power supply is likely damaged and requires repair or replacement.

Common Fault Scenario 3: Ammeter Pointer Does Not Move

Step-by-Step Checks

• Ensure the laser master switch is turned on.

• Check whether the indicator LED on the laser power supply is illuminated.

If LED is On

• Press the laser trigger button:

  • If the pointer moves but current is below 5 mA: The laser power supply is defective.

  • Adjust the laser intensity parameter in the control software and test again.

  • If the current still cannot reach 10–12 mA, the issue may lie in the laser power supply or the main control board.

By following these diagnostic steps, users can quickly identify and resolve common issues related to laser emission failure, minimizing downtime and maintaining optimal machine performance.