Had the same thing happen a few hours ago. Soft, hard, and safe mode restarts did nothing, nor did a factory reset. I called *Verizon* rather than Samsung, and, so long as there is no water or shock damage when they get the phone back (there isn't...it's never been water damaged and I both haven't dropped it in a while and have an Otterbox to keep it safe when I do), the replacement is free (I've only had it for 9 months). They're sending me the replacement overnight for a small fee (would have been totally free if I was willing to wait a week for the phone) with the assumption it's a free warranty replacement, and a prepaid label to send the old phone back. I'm sure they'll charge a warranty replacement back to Samsung, but if you got your phone through your provider, go through them first!