Indesit dryer stopped working properly ?

Got an indesit condensing tumble dryer, which i can normally repair no problems, but this problem has foxed me, you turn it on to go as normal but the drum turns about half a turn then the motor stops, but the water pump and heater element run as normal, so I guess it is something to do with the motor, but if it was the capacitor it wouldn't start to turn at all?
Await anyone's suggestions