I keep getting this error message when I try to run anything in Lightburn: “there was a problem sending data to the laser. The machine may be busy or paused.”
The machine works perfectly with LaserGRBL on my laptop with its included USB cable and also through Wi-Fi AP with LaserBurn on my phone.
This is my console
Are you sure that COM5 is correct for the laser? Mine uses COM3.
SHIFT+WIN+S opens the snip tool. Do that, then drag a box around what you want to screen capture. Come back to the fourm and CTRL+V to past the screen capture into the diagloge box. It works a lot better for us than a cel phone picture. 
Yes, I’m positive it’s the right COM port. It’s either 8 or 5 depending on which of my USB ports I have it plugged into.
Is this better?
You cannot have this open along with Lightburn. That message is saying the COM port was assigned to something before Lightburn got up and running.
It also has to be either-or for USB and WiFi.
I don’t have them open at the same time.
I’ll try disconnecting the Wi-Fi and see if it works.
I switched the network my laptop was connected to so that it’s no longer connected to the same one as the machine. this is my console, (it looks like it’s connected, idk what the problem could be)
It looks like it is still trying to connect to the WiFi using FIDO to log in.
I am guessing those are Console window captures. Have you checked out what is happening in the Windows Device Manager?
No I haven’t, what would I look for there?
Look for anything that might be competing for the COM port.
The connection itself seems to be fine. Those messages are coming from the laser and can be read fine. So this works. You might change the port parameters, first, change between buffered and synchronized modes for the COM port (device settings).
Try rebooting your computer
Tried switching between buffered and synchronous, no dice. Tried restarting, no luck. How would I check for other devices trying to use the same COM port? I don’t think it’s that since it works fine in LaserGRBL, and it doesn’t matter which USB port I use, they both don’t work in Lightburn.
With the laser not connected, open Device Manager. There should be no Ports line showing. Now connect the laser. You should get something like the image below.
If yours is in any way different, then do a snapshot (SHFT-WinKey-S) and add it to your Reply.
If you have LaserGBRL running and connected to your laser, you won’t be able to connect LB to your laser.
If you have 2 LB windows open only one will be able to connect to your laser.
If you have LB connected to your laser then open LaserGBRL, LG will take control of the laser and LB won’t work until you close LG.
But since you rebooted your computer all this is mote
Nothing is competing for COM 8 or 5 (my USB ports), and I don’t have LaserGRBL or another instance of LightBurn open at the same time.
Do you have a printer that is sitting on COM3? Please show us why you cannot use COM3 like the majority of the userbase.
I am a big believer in Occam’s Laser - keep it simple. Most people have com3 for their laser and nobody else in my recollection has had the same problem you are having. Ipso Facto - please try what works for everybody else.
COM 3 looks like it’s reserved for my bluetooth.
My USB ports, like I said, are COM 8 and 5
this is with my laser connected:
Turn off the bluetooth.
Connect the laser on COM3 with the USB cable.
Trust BUT Verify. Start with a known good configuration and then it will be a lot more evident what needs to be changed.
How do I change the COM port my USB uses?
