Hello, I purchased a G Weike LG900N 80W CO2 laser cutter ~1.5 years ago, and it has worked great at mostly light usage, until now.

But recently it developed this horrifying problem: the laser head sometimes loses the ability to go left. When I press the "move left" button, it goes right instead. Same thing when it tries to cut. When I first power it on and it tries to home itself, it just winds up banging onto the rightmost rail with a scary "BANG BANG BANG" sound, until I reset it.

I thought perhaps the X axis stepper motor was bad, and replaced it, but that did not fix it. Same problem.

I thought the problem was maybe caused by heat, because it would get into this state after quite a while (maybe an hour) of usage, and sometimes turning it off, letting it cool, and then on again, might fix it. But it's been off for days now, and I turned it back on and the same problem is there.

Has anyone else seen this problem? Could it maybe be a loose wire? How do these stepper motors know which direction to step in, when commanded? (Like which wires get which volts?) Or maybe a short circuit in the control panel (the board that has the buttons that I press)?

Any suggestions on how to debug or fix it? I could try replacing the whole control board, which seems to be on the lower back of the machine. I'll try to get its exact part number.

Thanks!

Mike