Are you certian that the camera stops working, or is the lense blocked just making everything black on the screen? You might simply have it positioned it in your phone wrong and thats causing it to not get a clear view out of the front of the screen causing the problem you are experiencing. Did your new screen come with those two little plastic brackets for the front facing camera and ambiant light sensor? If not you need to chip them off you old screen and superglue them onto your new one. Just take a pair of tweezers to handle the bracket, put a drop of superglue on a piece of cardboard or something disposable, and lightly dip the bracket into the glue on the side you are gluing down, then quickly get it on your new screen.