If your iPhone is unresponsive and will not reset, be sure to try these steps from the iPhone: Hardware troubleshooting article:
If the iPhone did not turn on, reset it while connected to the iPhone USB power adapter.
Connect the iPhone to a computer and open iTunes. If iTunes recognizes the iPhone and indicates that it is in recovery mode, attempt to restore the iPhone. If the iPhone doesn't appear in iTunes or if you have difficulties in restoring the iPhone, see this article for further assistance.