Light burn problem

THIS JUST HAPPENED A COUPLE weeks ago i go to engrave a 12 x 12 inch balsa plywood and it doesnt matter if i stsart from the bottom or top after about 1/3 thru the burn lightburn locks up, nim able to save the work rebbot it all then start from oposite direction but again locks up at about 1/3 way thru which really messes up my material aND TIME WAISTED THIS ALL STARTED AFTER LAST UP DATE I HAVE UNINSTALLED IT WENT Back to a earlier version but still happens, suggestions or fixes welcome ty

here are the problem results

Can you describe what is happening when this occurs? How are you able to save the work at that point?

i just hit the x to close light burn it asks me if i wANT TO SAVE IT HIT YES

In what way is LightBurn locked up in that scenario? What do you see that you’re reacting to when the burn fails?

laser stops movingb but the laser is still burning

its like a wire is broke that runs the servo motors

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This sounds like a very typical disconnect scenario.

Common causes:

  1. Bad USB cable - you could try swapping this out for another high quality cable
  2. static discharge causing USB port to reset - if your machine is not properly grounded this can occur
  3. noise on the electrical circuit - do you have any other equipment plugged into the same circuit as the laser? Perhaps an air compressor? Is anything turning on while you are burning? This could be enough to disrupt the communication to the controller
  4. EMF - if you have any equipment putting out a lot of EMF noise this could potentially disrupt your laser
  5. USB power savings - I saw that you posted to another post about this. Make sure that USB power savings is turned off
  6. Computer going to standby - disable any sleep operation while burning if you notice your machine going to sleep

It’s also possible that you have a defective controller but that’s less likely than one of these other issues.

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If this is the case it’s an indication that static discharge is the issue as image burns are more likely to cause static buildup than something like a line operation. Not sure where you’re located but weather changes could make the issue more pronounced with dry air.

Often times issues like this popping up coincide with new releases but are not necessarily caused by them. I had thought you had indicated that going to an older version had not resolved the issue. But if an older version resolves this completely then this could be a bug. If you still experience it then likely something more fundamental and you just haven’t seen it pop up as often by chance. Overall it’s unlikely that this is a core software bug as others with your same model or similar GRBL systems would likely experience the issue.

What sort of air assist do you have? Is it an aquarium pump style or a compressor? If a compressor, do you see the issue coincide with the compressor turning on?


I simply turned off a ceiling fan on the same circuit tonight (cannot dedicate the laser to its own circuit in my home) and it was enough of a change that the controller knocked offline at 92% completion on a 6 x 12 plaque. Paint me really irritated that we have no way to restart.

In case you’re not aware one potential strategy is to use the “Start here” button in Preview to restart a job at a particular point.

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Thank you but the laser lost COM and nothing I did brought it back. Finally had to reboot the software.

I’m new to LB and I’m still learning. Thank you for that tip.

Sorry. I didn’t mean as a way of recovering communication. Only in the sense of being able to potentially recover from a disrupted job. If your machine doesn’t reliably rehome to the exact same position then the recovered portion may not align quite exactly but will be close. Machines that rehome precisely won’t have that problem. However, I will say that it’s fairly difficult to get to the precise point in Preview to match where the failure occurred.

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One other thing… if you can’t get the laser onto a different circuit then introducing a UPS or some other power conditioner or EMI filter between the laser and the outlet could potentially alleviate the disconnects.


I had USB communication problems with my exhaust fan introducing noise into the engraver somewhere and stopping jobs - similar to what you experienced but mine would quit randomly. I used a long extension cord to move the fan to a different circuit.

I might take some time this weekend to see if the noise is in the power supply (brick) or the USB cable. Pretty sure it was USB cable noise because the engraver just stopped and LightBurn kept streaming.

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Perfect! Thank you.

I have the Universal Engraver and chose it a few years ago before other entry levels were available like today. It sat in the box for 2 more years due to caring for my elderly mother who passed away in 2020. Finally put it all together in 2022 and it is finicky. But it let’s me learn to troubleshoot and that’s important. At least I now realize that line noise is an issue. That controller went down the moment I turned off the ceiling fan. I live in a nice, large manufactured home with a good sized work space created for me yet the electrical is chained and I can only perform certain hobbies - ONE at a time.

I will look into line noise suppressors today.

I will get an UPS today. I thought about that at 12:30 am this morning when it all crashed. I believe this will be the answer.