Hi Jon,
Do you still have a warranty on the mill? If yes it's easy, have tech services put together a solution.
If you do not have a warranty there are two options, have tech service come out repair or if you are handy pull off the back cover, find the unit grab a part number order and replace. Seems fairly straight forward but of course if you repair yourself it's at your own risk!
If you don't have it handy here's our tech support number: 781 279 2771 x 4