Ultimaker 2 Feeder Won't Turn

[MaxN 0]

I work for a university and am setting up an Ultimaker 2 that we received from another department. I have carried out successful prints on this machine before, but a few days ago, I encountered a problem with the knurled feeder wheel.

 

The wheel will turn fine when I am loading filament (PLA and ABS); it gets a good grip and the filament extrudes through cleanly. However, when I start any print, even prints that have run successfully before, the wheel won't turn at all. The bed and nozzle temps are consistent with the settings I have inputted, and the X, Y, and Z movement follows the appropriate path and speed. All speeds show 100% of normal. It wouldn't call it a filament jam, because it appears that the motor isn't trying to turn the wheel at all. There is no rotation and no "ticking sound."

 

I performed a factory reset on the machine, and nothing has changed. I am running the default Ultimaker 2 gcode flavor and printing from an SD card.

Does anyone have any ideas as to why this could be happening?

 

Thanks, 

 

Max