This morning I woke up to find my iPhone dark. If I pressed the home button to turn on the screen, the backlight would flash on briefly and then die. I've turned it on and off, done a hard reboot ...
I have upgraded my iPhone 3GS to iOS4, but now want to go back to OS 3.1.3 that it had before. There are plenty of instructions on how to do this, but what happens with the data stored on the iPhone? ...