Lightburn burning horizontal streaks on images

I am using the latest software on a computer with Windows 11 on an Ortur LM3 10 watt machine.
It has started to burn horizontal streaks across the images.on 3mm plywood.
How can I fix this?

Show a picture. Otherwise, it’s not possible to judge. In most cases, it’s mechanical.

This can be due to the grain of the wood or the surface finish (or lack thereof) applied to it. If the problem follows the wood when you rotate it on the platform, it’s the wood.

But, as @misken says, it’s almost always a mechanical problem.

Having a DPI setting too low, or line interval too high, can produce this effect as well. a low DPI will not be noticeable on small images, but will easily show up in large images.

I have taken photos of the image but don’t know how to send them to this site.strong text

Lightburn burning horizontal streaks on images - #2 by misken How do I attach a picture to my post?

Hi Mike,
I am using 300 dpi and line interval 0.0836mm. Can you suggest something better?
Regards, Laurie.

There is an upload icon in the text editor:

Or you can just drag the image from Win Explorer to the Reply window.

That is probably good enough to prevent streaks (unburned lines). But, as @misken says, it’s almost always a mechanical problem. Providing a picture will definitely help. Often experienced users will notice important details you did not mention.