Stepper missing steps with no torque applied

One of my stepper motors is missing steps, even with no torque applied. I know the normal solution would be to tweak the pots, but my situation is a little weird, so I just wanted to get your feedback.

This is my second xcarve, first one has been running without problems for over a year. All parts arrived except the xcontroller, si I used my old xcontroller to test my setup while the new one comes.

So I’m using a known good xcontroller with known good pots settings.

However, the problematic stepper misses steps regardless of where I plug it, x, y1 or y2.

And the last issue is that in the current setup, this is stepper is assigned to Y2, worries that tweaking the pots will also affect y1.

Because of the specifics of the case, I’m thinking that tweaking the pots might not be the way to go, but I have no idea on what else to try.

Do you think a bad stepper is a possibility? How can I diagnose that?

You say annolder controller is connected to new machine.
Is it an X controller or a g shield?

It’s an xcontroller from 1 year ago. So Early 2017 version.

Y1 and Y2 use the same current limit setting.

A lot of work, but change the suspect Y motor with the X motor and see if the problem moves to X.

Connected the suspected motor to Y1, Y2 and X using the Y2 cable, it missed steps. Then connected the suspected motor to Y1 and X using the Y1 and X cables, made no difference.

Here you can see a video of the motor.

CloudApp

I think you have a bad motor. Call Inventables.