My iPhone 5 (jailbroken) was dead this morning - thought it was 'just' battery as the battery has been going quickly. No amount of charging is making a jot of difference, though. It doesn't show on iTunes. I can't get it to reboot (holding down power and home) or restore (holding down power and home for ten seconds, then letting go of power) or DFU - just a totally black screen. It doesn't show in Windows explorer at all. I've reinstalled all apple software (bonjour, itunes, quicktime etc). Any ideas? I'm trying to keep my cool but this is so frustrating!