I have a Laguna Swift 4x4 CNC router, bought it in 2016. I wasn't really sure where to post this thread so excuse me if I'm in the wrong subforum.

I recently moved shops and now one the stepper motors acts really odd and super jerky. It is one the Y motors. I've had this problem before, but only once or twice, and it would just disappear after a restart. Now it just wont go away.

The good motor will spin the correct direction, while the bad one will go randomly and only correct itself once the whole gantry is moving. It shakes the whole gantry sometimes and I'm afraid of damaging the frame or rails or something. It's the moment it first move that's the problem.

I recorded a video of the problem.

https://www.youtube.com/watch?v=zBDfy5b9F08

While I've personally ran the thing for 4 years, I know very little about how internals work. I've included photos on the internals if that helps.

Thank you