Laser does not turn on when giving the start command - GBRL M3 error, how do I change it?

[Yuri.R (Yuri Rodrigues)]

Hello!

I use Lightburn on a Two Trees TS2 10W machine
and it works normally, I recently bought another similar machine and the laser doesn’t come out when engraving the axes, it works normally, the laser just doesn’t come out. I have already checked the cable connections and tested various configurations, installed drivers and have not been successful.

The following error appears in the console.

"Your Grbl may not support variable power mode (M4)
If your laser does not turn off between cuts,
switch to GRBL-M3 device"

What could this problem be? Do I need to do any specific configuration?

[MikeyH (Mike Hembrey)]

@Yuri.R

recently bought another similar machine and the laser doesn’t come out

NO, do not switch to the -M3 version.

This sounds like the laser is not firing at all. Look for a loose connector or wiring issue. Check all wiring from the laser head to the controller board.