If you somehow managed to make your iPhone unresponsive or tried a jailbreak and ended up with a rather bricked device then follow the following steps to revive your device. This is like a iCPR with retrograde amnesia meaning your device will end up in factory settings with all the data deleted, (which if you happen to have a back up can easily restore).
1. Ensure the iPhone is off.
2. Insert the USB cable, then hold the Home key while connecting the iPhone to iTunes.
3. On the computer, when prompted that iTunes has detected the iPhone in recovery mode, click OK.
4. Click Restore.
5. Click Restore and Update.
6. iTunes will begin to restore your iPhone.
7. Restore has completed successfully.