My jailbroken iPhone 4 appears to be dead, except when plugged in via USB, it shows the Apple logo for a few seconds, screen goes blank and repeats forever. I entered both DFU & recovery mode in the hope I could factory restore in iTunes, unfortunately the Apple server must detect it's jailbroken and won't allow the update to conclude. I'm not that technical but did try a few suggestions on this forum, such as using TinyUmbrella (to no avail), also tried to re-jailbreak though didn't work in it's current state, and used iFaith but to be honest I got a bit confused and it said the only active SHSH blob is Cydia 6.1.3 so I couldn't go any further. Also the hard reset using the volume up button didn't work. I'm not that bothered about jailbreak now, just need a phone to work even if I lost all my settings. Does anyone have any ideas at all please, or could offer their support in helping me fix this? Thanks in advance.