I recently purchased a K40 laser cutting and engraving machine 200 x 300mm.
I have installed the lightburn software.
On the laser panel the printer is displayed as disconnected although all cables are connected properly.
My laptop is operating with windows 8.
Laser cutter disconnected on lightburn laser panel
I see you also posted in LightBurn forum and received some responses there.
For windows 8, did you install the drivers?