My 2g iPhone wil shut down on its own as soon as it starts. But when I take the SIM card out it will start up fine and I can use it has a iPod. I have tried the restore multiple times as well as downloading different .IPSW's I am using redsn0w-win_0.7.2. Anything I do my iPhone still shuts down. I tried starting it up then putting the SIM card in after it starts up but as soon as I call someone or after 10-30 mins it shuts down again then after that it just keeps shutting down when I start it please help?