If you have a box that you can do it with. Connect via wifi to a network and then ping the 770, keep the ping going while you put the case back over the screen. If the ping does not fail, it means that you're 770 doesn't see the case when it's on, and it's not going into stand by (you can probably test this by looking in the 1mm gap between the case and the unit to see if the screen is lit).