2006 Chevy Equinox - no heat.

[chucka]

Hi,
I have a 2006 Chevy Equinox, 3.4L, 67,000 miles with no heat. The air conditioning works fine. There is no loss of anti freeze. Everything on the web indicates it could be a blend door actuator (small motor) that is bad or the blend door is broken. When I turn the heat control knob, I could hear the actuator hum, but it didn't turn. So, I replaced it with another. The new acuator (motor) shaft did not turn when I tried to turn it by hand, so I rotated the blender door shaft and aligned it up and screwed it down. The same thing happens. I can hear the actuator motor hum, but I can see that it is not turning. What do you think is wrong. Thanks. (I won't be able to get back to you until this evening.)