Rear electric window

Hi, Today I have found that my drivers side rear electric window will not one click open or close. It will just move in inch and a half movements up and down. I have tried re setting the window as per manual with no joy. I was wondering if any one else has had this problem or knows anything to try. Thanks.
Oh battery has not been disconnected and not other work has been done lately.

Ive got this with both my rear windows, and the drivers window.........
and after opening the little blighters up, i came to one concusion;:fighting:
To quote the tv programme, 'Where all doomed....!'