GGTL12920 treadmill incline tries to work but gets "stuck"?

Prior to running a calibration, the display indicated fully inclined at 10 would decrease by .5 and then immediately jump to 0 and beep a warning - all without the deck moving. Then the reverse would be true...the display would increase from 0 to .5 and then immediately jump to 10 and beep a warning - all without the deck moving.


After recalibrating, the console correctly increments by .5 from 0 to 10 - so, apparently, the calibration procedure "fixed" something. However, even in the calibration mode, the deck only moves for about a second and then "hangs".

I removed the motor from the "shaft" and opened the gear box confirming that the gears are lubricated and moving freely. The windings and motor appear clean and the wiring appears intact.

I reconnected the motor to the boards, etc. WITHOUT installing it on the "shaft" and powered up. The motor gets power, turns and engages the gears - I can see the plastic threads that would be on the "shaft" turning.

So, the question is, am I installing the motor on the "shaft" incorrectly and causing the machine to "think" it's at a level it isn't?

It's counter intuitive to me to replace the motor when it seems as though the motor is fine - and rather something somewhere is not communicating back to the sensor properly?

Thanks for any ideas...
tlm