My Creda 34770 Tumble Dryer is making a humming Sound?

I have taken the top off the dryer turned the machine on, and helped the drum move - it move very slowly for about 30 sec and then stops - i have replaced the capacitor - and tested again and the same thing happens - any ideas is it the motor
I have check around the motor and there is no fluff or anything blocking it -and the belt is in tact