Laser does not emit light

1 if it is a glass tube. please connect the L-an to the IN pin on the PSU. and L-on to the L pin on the PSU
2 Then check the controller setting: vendor setting
3  Check the layer setting,Ensure the power setting has been selected and output is enabled
4 Now you can do a cutting in slow speed and check if the laser is ok. if there is still no laser, you should use a multimeter to measure the laser power signal and laser on signal.
4 Now you can do a cutting in slow speed and check the laser