In such a case, measure the voltage between the IN and GND terminals of the laser power supply across different power settings.

1. Open the cover of the laser power supply (refer to the video).

2. Measure the voltage between the IN and GND terminals of the laser power supply across different power settings.

• If the voltages measure about the same, the mainboard is faulty. Replace it with a new, identical one.
• If the voltages vary under different power settings, the laser power supply is faulty. Replace it with a new, identical one.