I can't say 100% sure but I get the angry GPS icon flaehing periodically just before my phone suddenly gets a circle with a line thru it where the bars of cell service should be. Nothing including walking to a cell hotspots where I usually have full bars work. Then my phone eventually locks up and I can't even power off. If I Wait for my battery to die or pull the back and battery out then I seem to have nothing but problemspowering back on
I get a gray battery flashes and then off it goes.(I have it plugged in). Finally after many tries it may finally flash to green battery and the sometimes I get lucky and press the power button it may finally flash to the Samsung startup screen. Yay! It once took around a day and a half of trying it finally went back on. Oh if the phone has the dreaded noways circle everything else still works. I can watch videos I downloaded or read an ebook or get emails or use the internet if I'm hooked to wifi . Can someone please help? My phones off warranty.