This machine as well as the R2E4 and the V2XT have a tendency to quill up and jam the quill up. Usually this is relieved by taking off the Z motor pulley, grabbing the pulley with channel lock pliers and grunting the quill down.
As you stand in front of the machine, your right arm will be at your left shoulder and will move the pliers across your chest to the right. Usually the plate with the screw to hit the axis limit switch bends and needs to be straightened out.
Then you need to figure out why this happened.