I serviced this NordicTrack C2500 treadmill in Windham, Maine.
The treadmill would turn on and the console would light up, but the treadmill would not run. The plastic cap for one of the motor brushes came loose and popped off under the pressure of the spring that holds the brush against the commutator. I located the cap, and put it all back together.
The wire lead pulled on the plastic cap due to too much tension on the wire because of how it was secured to the frame by wire ties installed at the factory. I eliminated this pressure by removing the offending wire tie, then went an extra step and placed some Gorilla duct tape over the brush cap and wire lead to help hold them in place and reduce the chance of popping off again.