X-axis stepper motor

#1
Hi,
I've been away for quite a bit but now I've finally got the time to check back in, and play with my printer :). I was left at calibration and leveling the thing after I placed it at my desk, which I just did. Now I notice that my x-axis motor is just not moving, also not when I adjust it in mm's via the panel on top.

What I have is the ldo 42STH47-1684AC.
When I adjust it via the panel, I do hear the motor making a sound but no movement of the axle. If I detach it completely and move it by hand, I feels like I'm grinding. Given the photos on the url above, I removed the top, took out the rotor but cannot see anything blocking it.

Someone has any ideas what might be wrong or what I should try? I'm quite surprised that it's just not working after sitting still for 2 months or so.

regards
Jeroen