my wm64 doesnt work!! help!!?

Hotpoint Aquarius 1200 WM 64

WM64, fills OK, timer moves on but drum does not turn. If timer is moved on manually, then cycle continues and empties OK but drum still does not turn. Belt is OK and drum can be turned by hand.
i have cleaned off any carbon build up from the motor rotor and it still does the same.

any ideas??