Wi-Fi icon shows, but won't actually connect to anything

Question

Hi all,
     Earler today, my iPhone 4 was working fine.  At some point however, the internet just crapped out on me.  The wifi icon shows up, indicating that it is connected, but when I go to use an application, it won't connect to the internet. 
     I have tried on 3 different wifi networks, so I know it is not my home network at fault.  I have tried forgetting, and then reassigning the network, and that didn't work.  I have tried using safari, the app store, and several other internet-using apps, so I know that it is not just my safari settings or something. 
     I have read a couple online forums, and it seems like a lot of people are having trouble after the 4.3.5. iOS update.  I can't imagine that apple would take this long to put out a patch or a new update if this one is causing so many widespread problems.
     If anyone can PLEASE help me with getting my phone back online it would be greatly appreciated.
Thanks.

Answer 1

EC-Sam wrote:
     I have read a couple online forums, and it seems like a lot of people are having trouble after the 4.3.5. iOS update.  I can't imagine that apple would take this long to put out a patch or a new update if this one is causing so many widespread problems.
Some people have problems after every update and between updates. But there are 110 million iDevices. Some of them will have problems at any time. For 110 million A LOT would be at least 10 million. Have you seen 10 million posts about this problem? or even 1 million? How about 100,000? 10,000? If you focus on the 4.3.5 update you will never solve the problem, because a quick search will show that there are always some people who have problems, including this one, and the reports go back 4 years. So instead forget that it is related to 4.3.5, because it isn't.
The fact that earlier today it worked, and now it doesn't and I assume you did not update to 4.3.5 in between, pretty much eliminates the version as having anything to do with it even in your case.
Have you rebooted the phone? (Hold the HOME and SLEEP keys at the same time for 10-15 seconds, until an Apple logo appears).
I know you are sure it isn't your home network, but humor me anyway. Reboot your home router by turning it off for about 15 seconds. If it still doesn't work go to Settings/General/Reset and Reset Network Settings. You will not lose anything, but will have to re-enter WiFi passkeys.
If you still have a problem do some basic diagnostics. Try to connect to a network, like your home network. Does the WiFi symbol appear and stay (not revert back to 3G after a minute)? Tap on Settings/WiFi and tap on the arrow to the right of the network name you are connected to. Look at the IP address. Does it begin 169, or is it 192 or 10? If it begins 169 this means that the router did not provide an IP address. If it begins with 192 or 10 it is connected to a local area network, which is good. If it is something else post what the IP address is; there's something very wrong.
Assuming it is 192 or 10, what is the DNS address? It may be 2 addresses separated by a comma; the first should be the first 3 triads as the IP address (e.g., if the IP address is 192.168.1.4, the first DNS address should be 192.168.1.xxx, where xxx is most likely 1 or 10).
The next thing to check is a computer connected to the same router. Can it access the Internet? It's always possible you have a local outage.
Assuming that none of these fix the problem Restore your phone with iTunes, and do not reload your backup. DO NOT SYNC, but see if it now connects. If it does work connect the phone to iTunes again and DO NOT SYNC, but right click on its name and chose Restore from Backup. If it still works after this you are home free, but it it doesn't you have a corrupted backup and will have to Restore as New again.