The LCD and Digitizer connectors on the logic board for the iPod Touch 4G are very delicate and difficult to access when attempting to reconnect the replacement Digitizer/LCD. Check carefully for any damaged or missing pins on the logic board and the Digitizer/LCD. If the connector on the logic board turns out to be even slightly damaged, it may be helpful to check out [http://www.ifixit.com/Answers/View/70398/Damaged+LCD+connector+on+the+logic+board|the posts] about my experience with this repair.