S9 laser just stopped working. Is it busted?

So for some reason the laser has stopped firing on my S9. It was working fine but then it wasn’t. It goes through the motions but the laser just doesn’t fire.

Is the diode likely dead? Is there any way to test it, I don’t want to buy a new one if the issue is software? Hitting the fire button in LB does nothing.


There are multiple ways to test. First, try to make sure the cable isn’t broken. That’s the most common reason for non-firing lasers. You can try to measure if it is intact, or you can connect the signal line to the 5V port of the mainboard. An explanation with pictures is here: FAQ - Diode Laser Wiki
Afterwards, we can try next steps.

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Thank you. I have done the test and the laser comes on, which is good. But Lightburn is still not firing the laser.
This did seem to happen after I updated LB… I have since uninstalled and reverted back to previous version. Still nothing, next step is the USB cable but I can’t see it being that because it has been working great.

Next thing is to try LaserGRBL just to make sure it’s a LightBurn-settings issue. In LigthBurn, check the device settings if the s-value max is set to 1000 and check the firmware settings, if all values are set according to the table at the bottom of this page: Firmware Update & Settings - Diode Laser Wiki Sometimes some users had weird settings in there, especially at parameters $30 (should be 1000), $31 (0) and $32 (1).


Thank you so much for your help. I don’t know why the setting in LaserGRBL where so off.
The laser did seem to stop after I updated Lightburn, does lightburn alter the GRBL settings?

It should not. But such reports and some strangely changed firmware values appear occasionally. It’s always worth to check it.

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