If the indicators on the laser power supply do not light up but any of the other parts have power, check whether the laser key has been inserted and turned in the right direction.

If the power supply remains unenergized, test the power output or input of the laser power supply with a voltage tester or measure the input voltage of the power supply with a multimeter (as shown in the video).

If there is input voltage to the laser power supply, the laser power supply needs to be replaced; if there is no input voltage to the power supply, check if the contactor inside the machine will engage when the laser key is turned (as shown).

Note: You can determine whether the contactor is functioning properly by listening for a clicking sound after turning on the key switch.

If the contactor does not engage, replace the laser key switch. If the contactor engages, then the contactor is faulty or the wiring has gone wrong, which can be confirmed by testing the output of the contactor with an electric pen to see if there is power. If there is power, the wiring has gone wrong and you will need to fix the wiring; if there is no power, the contactor is faulty, replace it with a new, identical one.