Laser not firing up

So i switched over from routering to laser…40w diode laser…got lightburn trial…grbl fluid nc…movements work well. Blue light on top brightens and dims when doing a simple square outline. I learned to put in laser mode. Laser doesnt fire up. I took off machine and put direct power and the units fan turns on and def works when i manually push the top button. I think maybe when my friend spliced the cable that came with it into new wire to my controller he may have not put the right lines together. Maybe the 24 volt power and the pmh got switched around. Would this still make a blue light on top? First time so i dont know of the fan is sopose to turn on right away so its ready to fire on cammand. I may have to get a colt meter and trace it back to make sure the power line is the power in the module. Any help or same problems would be great.

Hey there!! @Rolly :blush:
The blue light usually means the laser is powered but not firing yet. If the fan kicks on immediately, that can vary by machine. Definitely check the wiring your friend did—switching the 24V power and PWM could cause issues. Using a multimeter to trace the connections is a smart move. Also, double-check your settings in LightBurn to ensure everything’s configured correctly. If you have any other questions, just let me know!

1 Like

Hi @Rolly !

To provide specific feedback, we’d need information like what control board you’re using, potentially the relevant code sections from the config.yaml, information on the power supply, and exactly what wire is connected to which pins on the board. My laser setup is specific enough that I keep 3 config.yaml files, one for the router, one for the laser, and one for the laser with rotary axis (although this isn’t necessary for many use cases.)

If possible, the version numbers of each board and firmware involved helps as well.

It sounds like the laser is powered, but something is amiss. Could be a lot of things. Pin definitions, wiring changes, under-powering the laser, etc.

My sympathies, these are never fun problems to try and track down!

1 Like

Yeah it ended up being the yellow and red wire switched. Im not a wireing guy…my friend did that part and he didnt notice they were switched around and that was the end that came with the laser. He ran new wire and spliced it into the connector that came…we didnt check voltage because i was fooling around with routering for a while but he ran the line for when i was ready. Fustrating but now the fan on the module turns on and when i push button it gives me a blue dot. Fricken love it. Im upstairs watching “love is blind” oviously only thinking about my laser and burning that first line lol.