NordicTrack C900 Pro Won't turn on
Double check:
Chances are that "$%#T Happens" is not your problem. And that if it worked prior to "dis-assembly, it should work after re-assembly". The common denominator is you took it apart & put it back together. So.. something was missed. A wire not connected, a switch not flipped, a wire in the wrong spot, the safety key not in the slot, etc, etc.
Good Luck