My uncle decided to finally update to iOS 7 the other day, after much convincing from me. So I hook his phone up to my computer, make a backup, and hit "update". The phone wipes everything, starts installing iOS 7, gets about 3/4ths of the way through and then spits out an error message in iTunes. "An unknown problem occurred (1669)....". The phone can now only boot into DFU mode, and every time I attempt a re-installation it gives me the same error message. Apple won't touch it apparently, because I replaced the screen for my uncle. Does anybody have any experience with this? How on Earth can I fix it. Since I did all the convincing, all of this is my fault (because that's how family works).