Help! I have an iphone 3gs which can only get cell, wi-fi etc while I am at home or in the 3 blocks surrounding my house. Otherwise it is "searching" or has "no signal" Do you think it could be a bad sim card? It does not seem to be able to find other cell towers. I have done the following: reset network settings, reset all settings, and restored from back up. The phone has never been jailbroken or modified in any way. My next step is to do a complete reset and set up as a new device, any other suggestions?