i was charging my phone and then received a phone call which lasted for about an hour, the battery was at 80%. about ten minutes later, i decided to sync my iPhone with iTunes and received a message that my phone wouldn't sync with my iTunes cause the sync session failed to start. i restarted iTunes, same error message. i decided to turn off my iPhone and try syncing it to iTunes again. but after i turned my phone off, it wouldn't turn back on. it goes to the start up screen (with the apple) but won't boot up the whole system. i've tried holding the power button with the main button to reboot it but it doesn't work. is there anything else i can do or do i have to bring my phone to the Apple store?