Thanks to Nick with the link to the photo... I have a Horizon CT5.2 with an E1 message. Belt lubed and fine, electronics light up but not running.... Nick's trick did it. (Fingers crossed!). For my model, the sensor is attached by an L bracket with 2 phillip's screws... I jiggled them back a bit, tried it. Nothing. Forced the belt with my foot in frustration and voila! Put it through the paces, on and off etc, seems solved. Thank you Nick!
Sam, November 2013