I have a fairly old Nexus S (Android 4.1.2). For some reason or other it switches itself off if not used for a few hours. I then have to go through a re-boot and PIN No. routine to use it again. While it is off I frequently miss calls.
I can't find anything in "Settings" which will enable me to adjust the period which it remains active.
Has anyone else experienced this?
Any help greatly appreciated