Originally Posted by
Minchan Han I wouldn't get the notification but I went way back and checked and it wasn't there.. Could you please repeat it here?
It may have failed to send, in which case I apologise. I said essentially the same as SactoKingsFan; enabling Developer Options, intentionally or unintentionally, will not void your warranty. With most phones, rooting will do so, but you cannot have rooted your phone in that way, as SactoKingsFan says.
A faulty SD card may cause the problem you are experiencing, and also a failing battery. I agree that a Factory Reset may fix the problem, if you are prepared to go to that much inconvenience. Let us know if you wish to try that....we have guides that you may find helpful.
Welcome as a new member.
Sent from my iPhone 4s using Tapatalk