Many customers are facing issues of sleep functions not working properly after they replace the A2681 lcd screens. It is due to the magnet orientation issue. To solve this problem, customers have to make sure the re-position this magnet to align with the direction of old screens. As you raise and lower the display, the arrow and magnet rotate in kind. Near that magnet-capped hinge, inside the bottom case, is a new sensor on a flex cable. The sensor can detect the hinge magnet’s angle, and presumably also keep count of how many times the display has been opened and closed.