I have an unrooted Galaxy S3, with official Samsung Android 4.1.2 ROM.
Yesterday the device just started to turn of the screen without locking the phone and before screen timeout, and it just won't stop !!!
I tried to change the screen timeout duration, didn't work, I stopped the Galaxy S3 feature smart stay and set it back on again and again and it's not working, I googled this problem and I can't find anything related..
I only have one option to do, and I wish I'm wrong, which is to do a factory data reset
I'm afraid that there might be a problem in the power button, again I hope I'm wrong.
Please any help is very much appreciated ..