1. Open the back access door and check

• Whether the laser tube is cracked.
• Whether there is water in the outer tube.
• Whether the anode line insulation is broken.

Any of the above conditions require replacing the laser tube.

2. Open the access door (left or right access door).

3. Check whether the laser power supply is normally energized. If it is not, refer to the Laser power supply indicator not lighting up>> for troubleshooting.

4.  Make sure the power potentiometer of the ammeter is adjusted to the maximum (only applicable to certain models).

5.  Set the maximum and minimum power to 45%, and press the panel pulse key to test. Check the laser tube’s status and the laser power indicator’s status.  

6.  If the laser fires as expected, the previous power setting might have been too low, resulting in the laser tube’s failure to start. If the laser fires but the laser power is subpar, refer to Weakened Laser performance>>.

If there is still no laser, check the power supply.

1. If the laser signal of the ammeter is always "OFF", short the L and GND ports of the laser control terminal of the power supply with a wire (as shown).                                                                
2. If the laser signal turns to "ON", check the wiring between the laser power supply and the laser control terminal of the mainboard. Replace the mainboard with a new, identical one if the wiring is normal.
3. If the laser signal remains off, replace the laser power supply with a new, identical one.

If the laser signal of the ammeter changes to ON when the pulse key is pressed, check the current value.

If the current value is always 0-1mA, unplug the laser control terminal (6-pin terminal) on the power supply(as shown). Press the test button on the power supply or the test button on the external ammeter (if applicable) to see the current value.

• If the current value is still 0-1mA, see Ceramic resistor test>> to find out the faulty component.
• If the current value reaches about 10mA and the laser tube emits laser normally.

Measure the voltage between the IN and GND port (as shown) of the laser power supply with the pulse key pressed (normally, the voltage is about 2V).

If the voltage is normal, replace the laser power supply with a new, identical one. If too low, replace the mainboard with a new, identical one.

       4. If the current value is about 10mA but the laser tube seems not to respond, replace the laser tube with a new, identical one.