Just had this happen to my VZW Galaxy S4. I tried banging the phone method & IT WORKED!!!! I banged it on my dish TV remote since it has the raised soft touch buttons. I was banging the phone PRETTY HARD. Guess what ever shortage was happening got fixed. Seems to be a time tested ultimate fix it recipe! Good luck to those who're having the same issues. Can't wait for my upgrade in June to go back to iPhone!