You may find that your iPhone boots up fully but is restarting periodically over a set period of time, most commonly after 3 minutes. The first step to solving this problem is to examine the panic log within the iPhone's settings. You can find this by navigating to Settings > Privacy > Analytics & Improvements > Analytics Data > panic-full-(date).ipsAfter pressing "Analytics Data" remember to scroll down until you find the "panic-full" field. It can be far down the list sometimes.Your Panic Log"