Possibly fried my control board/erratic/grinding Y axis

Heya laser squadron,
I have a self induced control board issue, I want to know if I fried my Y axis or this is fixable.

Basically I was hooking up a rotary attachment but the wires needed to be switched around. I seemingly have toasted my Y axis output from my control board. If it’s not toasted , it’s at least confused.

X axis output on control board works fine, rotary and Y motors work fine, but everything is grinding/erratic when plugged into Y axis.

Also grinding whilst machine is switched off but still plugged into Y axis output, as soon as its unplugged - smooth as butter.

  • standard OMtech k40, with the board that’s compatible with lightburn. (I have no idea exactly what it is-see pics) For reference the rotary is a creality one, and the wires are different to most. Helpski pleaseee

Usually, swapped wires of a stepper motor do not cause it to burn. A standard method to find the correct wire order is to start with arbitrary wiring and switch wires after another to find the working order. I never fried any driver using this technique.

But it still behaves erratic if the original cables are connected? This could indeed be a sign of a broken driver, though the cause is not obvious to me then.

I changed the controller to a grbl. It’s not a Ruida.


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I heard a large electric motor spinning up - like a shop Vac. You may find that larger electric motors can put electrical noise into the communication channel.

Please tell us more about your set up. It sounds like a shop vac spinning up. :slight_smile:

I heard the happy Microsoft Windows ‘happy-bonk’ sound… so, I presume the USB connected. Were there any disconnect messages in the Console window while your engraver was misbehaving?

Selecting the Show all switch in the Console window may double your chances of seeing electrical noise.

I look forward to knowing more.

Heya, this is what I have, nothing fancy, not many add ons - DF0812-40BN 40W CO2 Desktop Laser Engraver – OMTech AU

That motor spin up noise has been like that since day 1 and not caused any problems, and the control board works fine. Connects fine, sends signals fine except to the Y axis out.
Ill try the show all thingo when i get home later.

I specifically swapped Y axis wires while it was on, dumb i know, but im not sure if thats cooked anything

Some of us do this, however we know the risks, it’s bad practice and we don’t do it when trying to troubleshoot something.

You should be able to power it down and swap axes… On the Ruida I can esc out of the boot sequence I don’t know about you… If you have switches you can manually think it’s homed.


Im not sure i know what you’re saying - my problem is not the homing or startup or anything. I was just showing what it looks like when it moves - it does the same thing if i move it with lightburn, or even while its switched off theres resistance into whatevers plugged in, in the y axis

It will be if you swap axes connections … It has no way to know you’ve changed the hardware configuration.

Good luck


I gotta be honest, youre confusing me more and more with every message. I have no idea what your suggesting i do and/or what you are suggesting the problem is.

I think ill just buy a new driver

I believe the intent was to swap the x axis and the y axis and see if the problem moves.

Oh well i thought i explained this haha, but yes the problem moves. It happens to whatever motor is attached to the Y axis output. Whether that be the Y axis, X axis or the rotary itself. Whichever one is plugged into that output has a weird grinding resistance

As far as my expert opinion goes - it is the Y axis output of the driver/control board that is fried. I just want a suggestion on whether i buy a new one or it could be fixable/firmware related

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If the problem moves when you swap it, it’s likely a hardware failure in the driver circuit. It’s possible that it’s a cable, but unlikely.

On your board these drivers are under the heat sink. Some can be changed out, some can’t.

It’s likely more sensible to change out the board.

Make sense?


Yes, thanks :smile: that would require resoldering a bunch of stuff and would more than likely be more worth my time just buying a new one?

And if so, any recommendations?

How old is the machine? I think I would email Omtech and see if possible warranty.

If it’s the board and you replace it, it should just plug in with no soldering… yes?