Why is my wifi all of a sudden just not working. I have done all the resets and it still just searches for a network. My sister has the same 4s, we bought them at the same time and she can sit next to me and be connected to a wifi mine can't even find?
Reset network settings in the reset on device. If this does not work, delete wifi settings and try to connect to it fresh by putting in the password as if first time connecting. Also make sure you do not already have the max amount of devices on the wifi already as most routers max at 6-8 devices unless you go higher end. If these all fail to fix issue, take to apple store / sprint store <-- only if you have tep, to have device looked at as this would be a physical issue and not a service issue.