After a few years of light use, my LS3020 has failed.
The problem appeared to start with intermittent connectivity with the pc. A replacement usb socket sorted things out for a while, but I found the cable too easy to knock, so that didn't last long. A second replacement socket helped some, but proved unreliable.
Just to make sure I had the right diagnosis of an usb problem these were the (inconsistent) symptoms. When trying to cut or engrave , a communications error popped up on screen. Oddly the "go to x,y" button on screen worked, and the head could sometimes be moved with the on screen arrows, but the cut would fail.
A different behaviour showed towards the end. On clicking on the start button on screen, the head would move to the start of cut position, but no further, although I think the laser fired briefly. The final failure was smoke from one of the stepper driver (?) chips. By that time I had removed and replaced the board so mant times I may have swapped the two identical plugs on reassembly.
So are the symptoms consistent with a failed circuit board, or something more serious. Additionally if it is the circuit board, is it a straightforward diy replacement, assuming replacements are available.