I just fixed same problem - lights ok, no motor.
!!! If you're going to attempt this make sure the hood is isolated from the mains !!!
I removed the switch box (remove greasy grilles, remove 2 small screws holding the box in place), and opened it by removing 4 further screws.
There was a burned out solder joint on the PCB which had effectively disconnected power to the switches. I cleaned and repaired it, then refreshed the rest of the solder joints as there were a few others which looked cracked. Mechanical stresses from the switches, I'm guessing.
It's now as good as new! Which is to say noisy and ineffective :D
charlie robson, September 2013
