my coolpix l810 camera lens retracts & extends when turned on, back & forth several times before giving me the error message to remove cap. There is a tiny clatter inside when i shake the camera, but that has been happening for months with no effect, the in & out thing just recently started. I got it past the lens error to take pictures a couple times, but still having problem, tried to unscrew back & take apart to remove spring or screw or blow out dust making lens repeat start up motions, but can't pull back off, can't find where it's attached at the top.