Are you sure that the mechanical part of the "chicken foot" behind the outer gear is working? From memory the switch on the back of the chicken foot triggers slight hesitation from the motor drive circuit and that's the moment that the big relay on the main board (I think) switched to reverse the DC to the drive motor. I can't remember where the drive for that relay comes from at the moment.

I'm on hols at the moment, I'll have to search my workshop in a week or so when I get home to see if I still have my circuit notes from last time I repaired mine (different fault though)

Hope this helps