I broke my iPhone 4 and wanted to replace the screen with parts from a different (water-ruined) iPhone. But when I did this I got the display (upon turning it on) that indicates the phone has been locked and can only be used in emergency. I thought as long as nearly everything (most importantly the logic board) was from my original phone, then there shouldn't be any problem. But obviously there is. So now I'm wondering what parts I need to make sure not to change on my iPhone in order for it to still be considered my iPhone! Can anyone tell me what would be causing my phone to get blocked when the logic board is the same as it was before I broke it? I have never reported to ATT that I lost my phone so it is definitely not my logic board.