Laser not firing k40

Machine: _K40 m2nano

Board: LaserBoard, Mini,

Firmware: _Smoothie

I did go through all information on laser not firing .Laser will fire only on test, if disconnect the white connector on laser board and jump laser fire and laser ground it will fire if I run G1 x50 S0.1 f600 laser will move but not fire red light on laser board will light up red if I jump laser board L to Ground it will not fire the laser

I can not up load pictures due to being a new user ?

you can now, i’ve upgraded your forum status such that you should be able to.

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Can you tell me how to upload pictures thx


I did install the m2 stock laser board today it works fine with K40 whisper will not work with LightBurn
Thank you

MLE-40, laserboard,
Installed have gotten the wiring to work correctly- gantry moves as designed-
Cannot control laser- can see the light on laser board showing that laser is firing but nothing from actual machine.
I can switch the laser switch on the MLE40 and the laser comes on and stays on. Only exception is if I unplug the yellow/green wires between LAserboard and MLE. When that connector is unplugged I can test the laser with the two green buttons.

I have an ohm reading from between the yellow/green wires from the laserboard- .163 ohms 0V. (I hit the “fire” button on the lightburn console with no change)
If I test between the pins on the MLE board I always have 5.35v whether the red switch is on or off.

I have been fighting this a year on and off- bought the board and haven’t had alot of time to mess with it since it didn’t work right off.

Any ideas would be appreciated- I’m about ready to throw it all away from all the time I’ve spent screwing around with it.

do you have any pictures of your wiring?

I just bought a new laser power source and will see if that takes care of it if you could look at the wiring and see what you think.


As far as i can see you need to move your yellow wire one place.

green = laser FIRE
yellow = laser GND

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