One thing that can make the screen suddenly turn off is a magnet--if it gets close enough to the smartcover sensor (which is often located somewhere at the left bezel for a tablet, but might be in a different location for a phone), it might activate it, which causes the screen to go to sleep. This is how those smartcovers cause a device to sleep as soon as you close the cover, and to wake when you open the cover. Is it possible that there's a magnet getting too close to the phone's sensor? Is it in a case?
11-15-2014 11:44 PM