I upgraded my jailbroken iPhone 4 tonight only to turn it into my new paper weight. I backed everything up, put the iPhone into DFU mode, did a fresh install of iOS 6 and it was all going fine as a normal iPhone and after playing with it a bit before I was going to Jailbreak the phone just went to a black screen with the loading icon (just like when your battery dies) and the iPhone turned off, my battery was at 100% and plugged in to my Mac mini when this happened. I figured maybe it was a battery icon bug and my battery was actually dead so I didn't think much of it and turned the phone back on and it wont leave the Apple Boot Logo no matter what I do, it simply will not load. I put my iPhone back into DFU mode and restored again, it all went fine until the Apple logo appears on the screen with the progress bar below it and then again it all goes away to that loading logo in the middle and the phone turns off. I've been looking this up and trying different methods of restoring my iPhone for hours and have given up at this point. I don't know what to do from this point but my iPhone will not load or restore to anything passed the Apple logo. Any suggestions? It's a first generation iPhone 4 with the bad antenna before the white iPhone was released if that helps.