fan not working

ive got a problem with a fan that i bought from my local hydro shop its a vk 100 inlne fan. now ive used this fan for one crop without a problem then wen i went to start my current crop the problem started. wen my fan kicks in it doesnt start up u can hear the buzz of the electric but the fan doesnt go round unless i put my fingers inside and spin the blades then it will pick up speed and work like usuall. ive never had this problem with fans before so has anyone got a clue wats wrong with it and if i can fix it.... any help or ideas would b great. many thanks mayfair

the armature inside or the brushes are burn if it's not under warranty take it apart clean the armature with denatured alcohol do not use sandpaper

take the brushes out and very lightly polish them with 2500 grit metal sandpaper
then use a very slight amount of di-electric grease where the brushes contact the armature

this is how i rebuild electric motors for hydraulic pumps if i don't have parts readily available you may be able to go to radioshack and buy new brushes but i am unsure if they carry them

The fan motor and fan blade assembly ride on a shaftâ?¦that shaft rides on bearings or bushings. It sounds like a few drops of lube in the right spots will get it back to â??rightâ?�.
If you can access those spotsâ?¦.lube emâ??.
I use tri-flow Teflonâ?¦..no WD40 thoughâ?¦..itâ??s death to things electrical.

HMR