Lightburn wont recognize K-40

Hey all
Went to do a quick project yesterday and Lightburn refuses connect with my K-40 all of a sudden. I have an Omtech K-40 and Omtech Lightburn board. It connects just fine with my bigger 60 watt Omtech and my Xtool D1.
Computer makes the ‘ding’ sound when plugging in the USB cable so it is connected.
I’ve tried everything I can think of including nuking the K-40 and reinstalling it in the program.
Is it possible the board has gone bad? Plugged into an APC 1500 so no spikes getting to it.

Check the device manager and see if it has ID’d itself. Not a windows person but I’ve had them ding, then drop the connection.

It might require different drivers depending on what usb chip they use.

Hang in there and we’ll figure this out… there are a lot of people that have these.

You do have a compatible controller… just checking as it won’t work with the stock nano.


Yes, bought the Omtech Lightburn board at the same time and installed immediately. It’s been working fine over a year.

If it’s been working you have ether have a windows update or there is some kind of hardware failure.

You can try swapping out the usb cable.

You’re sure there wasn’t any modifications?


No, nothing changed at all… Just weird. I did change the USB cable and still nothing. I even rolled back to an earlier Lighburn version and no help… Guess I’ll have to get a new board. laser fires fine with the test fire button.

Have you considered rolling windows back to when it was working, to rule out a windows update as the cause ?

Since it’s worked for a year and it’s not software, that only leaves hardware.

Software has bugs - hardware breaks.

Since it’s worked for over a year, it’s got to be wired correctly. That leave only the control board or power supply.

If you’re going to pitch the board you could look for a firmware update, although it’s unlikely that there is one and very unlikely it’s firmware, if it’s been running a year.

I’d suggest you double check the connectors to ensure there are no connections have wires that have worked loose. This stuff is pretty dependable for as much as it’s pounded on.

Good luck


Thanks Jack! Ordered another board.

Good idea. I’ll try that!