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Laser won't power up

Recently bought my first laser from OmTech 40 Watt Blue. Unhappy with software etc so I took some advice and invested in Mini Gerbil and lightburn. After install the controller powers up, green light lit. Laser head will move to home but the Laser tube will not power up. I've checked and rechecked my connections but I'm stuck.

OMTech 40 watt,

windows 10


Any advice or suggestions? Please Advise

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Hi Greg, in order to fire the laser, the laser enable signal labelled 'LO' should go to logic low or gnd (ground). If you have a multi meter then you can measure the voltage level on the LO terminal at the k40 power supply. If you don't then you could test it by removing the LO wire at the MG (mini gerbil) side or K40 psu side and temporary ground that terminal (K40 side). If the PWM is wired correctly then the laser should fire when executing a test pattern via Lightburn (i.e. square or circle, power setting 10 or 20%). If it does not then the PWM connection or function is not working. If it does work then you need to look at the LO connection. Next step is to see if it is the wire or the board or the laser tube itself and let us know. You can push the little button labelled Test on the k40 power supply to see if it fires as well. Let us know your findings and we can take further steps.

Cheers and good luck

Cheers, Paul awesome.tech


Thanks for your response. This being my first Laser experience I may have misstated the problem from the start.

It seems that none of my K40 laser control functions work, the power control panel on my machine is inactive. Following your advice, I attempted a test fire by pushing the test button on the K40 power supply and the result was that the laser did fire.

My test fire resulted in two separate burns as shown in the attached image.

Is this function now totally dependent on the settings in Lightburn?


Thanks again,


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Hi, did you ever get this working with your machine? I ask as I have an OMTech also. Thanks

I have gotten the machine working, however once I installed the mini gerbil the power settings on the machine were disabled as was the test fire switch.
a bit frustrated with the lack of documentation as to what I could expect after installing the controller. I’m a beginner at this and it can be frustrating at times.

Thanks for the info Greg. I’ll be buying one and see how it goes.


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