HT1695: iOS: Connecting to the InternetLearn about iOS: Connecting to the Internet
Currently Being ModeratedDec 1, 2012 2:48 PM (in response to CKay82)
Go through the procedures outlined on this Apple support document. Start at the top and continue down the list until you find one that works.
Currently Being ModeratedFeb 2, 2013 11:50 AM (in response to CKay82)
Possible solution. After researching this for a friend (iPhone 4S) here and elsewhere online, turned out he had AppleCare and a phone call to Apple solved the problem. The Apple tech told him that this occurs in less than 1% of iPhones, and is almost always related to a glitch during a system update over wi-fi. He said people spend too much time on support boards, and should be calling Apple! (lol).
The solution is to plug the phone with a USB cable into iTunes on a computer and do a manual "Back Up Now" of the iPhone to "This Computer", not iCloud. Then completely reset the iPhone to factory settings, using "Restore iPhone" in iTunes, or "Erase All Contents and Settings" in Settings - General - Reset on the phone. Then "Restore Backup", again using iTunes. My friend said this fixed the "grey-out" wi-fi settings slider, and restored full connectivity, and he didn't lose any data. Hope this helps some of you! (I personally had no problem with my own iPhone 5).