my iPhone has been freezing up lately... A LOT! (won't wake up from sleep) i don't want to bring it in bcause it was also like that on the previous one that I replaced because there was that huge yellow tint. anyone else experiencing the screen not turning on and then you have to reset the phone? and should I bring it in to exchange? i brought it in a few times before. i don't know if they flagged me lol because of their faulty hardware.