Nordictrac c2050 Wont Lower the Incline

I have a Nordictrack c2050 that will fully incline when powered on and then not lower. The motor hums when the key is placed on the activator pad, however, the treadmill will raise all the way to full incline and not come back down. Removed the incline motor from the mill and plugged the wires back into it. Again, the motor turns the screw to the fully extended position and then wont go back to the fully down position. Checked the switch on the motor, it has continuity when the magnets in the transmission aligns with the switch. Tried to calibrate and it shows the "--" and just makes the motor turn all the way inclined. Any help is appreciated.