blurry rear camera ipod touch 4
 

Hi,
have an ipod touch 4 that doesn't open camera.
Looked at the rear camera and flat was damaged, so bought a new one.
Now the camera display blurred captures.
Tried to remove all kind of sticker and so on but still blurred :(

noticed also that the little spring near the rear camera is missing...what is its function?
Could i repair it?