Hello, my Macbook Pro Core i5 2.40 GHZ doesn't want to charge. When I plug the magsafe, the screen becomes brighter and the battery icon show that it is plugged, but is also says "not charging". I've read on the internet multiple users are having this issue. But it seems to want to charge when I put it on sleep mode. Anyone has any idea if this is normal or if there is a fix for this?