I really need Help

I been trying to see if someone can help me, I try several things but nothing is working, can someone help me, I’m frustrated, thank you, have a nice day.


Homing fail. Could not find limit switch within search distance.

Defined as 1.5 * max_ travel on search and 5 * pulloff on locate phases.


Grbl 1.1h [‘$’ for help]

[MSG:Check limits]

[MSG:‘$H’‘$X’ to unlock]

[MSG:Caution: Unlocked]


I’m not familiar with the Atomstack x20 Pro - I see it advertised as supporting homing, but I don’t see limit switches in the photo. If it does have limit switches, check to make sure they are wired correctly / the connections are seated well.

If it does not have limit switches, you’ll want to turn off ‘Auto-home on startup’ in the Device Settings window in LightBurn (‘Edit’ > ‘Device Settings’), and you’ll need to home it manually instead.

If it has switches that appear to be wired correctly but aren’t working, or homes through some other method than physical switches, you’ll need to contact Atomstack for support on that.


I had somethng like this occur on another CNC machine. Turned out to be a loose wire connection. The machine moved there, tripped the switch, but the software didn’t sense the normally closed switch actually change to open.
Found it myself by using a multi-tester set to continuity check and probing around.
Good luck!

Thank you for the information, I did that, but the problem is I lost the homing, and every time I want to engrave and see if the frame is correct, it doesn’t do it, I lost all the settings,

By ‘did that’ do you mean you turned off ‘Auto-home on startup’ because your machine does not have limit switches?

If that’s the case, you’ll need to manually home your machine by moving it by hand to the bottom left corner before turning it on in order for the ‘Absolute Coords’ Start From mode to work properly.

Here are some resources on the way the different Start From modes work:

If your laser does have limit switches, and you’re unable to get them working properly despite checking on the wiring, you will need to contact Atomstack, as that is a hardware issue.

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Thank you JTR, you are right, I contacted Atomstack that I have this problem, and told me I have to upgrade the driver board, for doing that I have to have a window laptop, because I been working with my iMac. so now they are going to sending me a new driver board, so with your advice now I think is the machine is having problems, again thank you for your help, when I receive the driver board and do the change I send a message to telling you it works, have a nice day.
Sincerely Jose


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