I have a similar problem with my cousins iphone 4 which i offered to look at for her. I have been told that the phone was i great working condition until the phone started to install ios 7 at which point the phone has frozen/crashed, and now wont work at all. The phone does not show any sign of life while not connected via usb (3 different fully charged batteries have been tested). A Couple of time when pluged into the wall socket the phone has booted up to emergency calls only. When plugged into the computer it boots to the apple logo, and then restarts - sometimes it goes to itunes logo. Now i have tried several different programs that are supposed to help put the iphone into pwned dfu mode, i have also tried normal dfu mode and restore mode, all of which fail to get past the "Preparing iphone for restore" in itunes, as the phone reboots and goes back to loading either the apple logo and restarting or itunes logo. Then itunes displays error 21. At no point have i seen the phone boot to an Apple Logo with...