Try opening the phone, then unplug the batter, remove the tiny shield and reconnect the little cable (the round one) also make sure all of the 4 teethe from the speaker dock, are plugged down below the frame. Good luck! ;)
Hi, I have had gosh darn worst experience with these boogers. Try opening the phone by following these directions: 1. Unscrew the two screws at the bottom of the phone. 2. Use a put a suction cup right above the home button and lift straight up slowly but be careful, there are three ribbon cables still connected to the top. Lift until screen is loose and hinge from the top at a 45 angle and unplug the number one cable (sometimes frees on its own) 3 lift slightly more and unplug the #2 cable. 4. The number 3 cable is locked by a white or black flip bar. Flip it up and slide the flat cable out. Now look at the gold prongs at the bottom of the phone. Lift up GENTLY on them but not too fast or they will break off Then reverse the steps and viola.
in the case of being stuck on the apple logo I have a soulution for you. i repair iphones and I had the same problem. Try disconnecting the number 3 cable and booting it up, without having the 3 cable in the socket. If it boots try putting it back in and boot up. If it boots up, great if not, replace the prox sensor or even the whole midframe (i would go with mid frame). Try and let me know!