Hi my guess is that your wifi chip is faulty, and to replace this, you need chipset level skill, and i dont think it is the wifi cable or antenna, hope this help cheers!!

I opened the phone and identified the location of the wifi module and heated it up with a solder station heat gun, whilst protecting other areas of the phone with heat shields. This essentially reflowed the solder which connects the module to the main board. It fixed the problem for me. It is a similar problem that people experienced with the PS3 system, where the main CPU became unconnected due to poor solder joints.

Putting your device in a freezer really doesn't do anything other than cause some contraction of electrical components that may or may not fix a short. Problem with this is if it's temperature related, you'd have to have your phone froze all the time to work. The one thing you can do is take the back off and check that the antenna cable is connected all the way. But, even if it's not, your WiFi should not be grayed out. Have you tried to re-flash your phone on iTunes? Maybe try a complete factory restore and see if that helps.

I'm leaning towards Wee Anrul's answer that you have a faulty wifi chip.

Good luck!

Ken

I note that you have updated to iOS 6, this maybe the reason.. Google it, there are many cases of iphone4S wifi problems after 'upgrade' to iOS6 including greyed out wifi. Its not a hardware issue, don't repair it. Wait for the iOS6.1 (apparently iOS 6.0.1 doesn't solve the issue).

Best of Luck,

Saq

Edit: This might help (some weird solutions) https://discussions.apple.com/thread/431...

Does the device pick up a phone signal? If not, your problem could be related to your baseband. It controls your WiFi, Bluetooth and phone signal. What baseband are you on? Check by going to Settings>General>About>Modem Firmware.

It's best for you to either

A: Should you have a good knowledge of fixing electronics:

Replace the iPhone's logic board, but before, make sure the Wi-Fi antennas are seated correctly.

B: You have no experience or are scared

Get a new (i)Phone or send it to Apple should your iPhone be less than a year old, they will most likely fix it for free, under their Hardware Warranty Policy.

I had the same thing happen last week to my 2 DAY old iPhone 4S, it was a hardware issue, I brought it to the Genius Bar and was given a new phone (after talking to Applecare). If you are not near a Genius Bar I'd call Apple, Applecare said I didn't qualify for tech support (as this phone replaced 2 previous phones that ALL had issues) but you can request a phone call if it's a hardware issue.

dfu mode

then restore from itunes end of

There is still one way that remains to fix it, when you were on IOS 5.1.1 and if you saved your S.H.S.H Blobs for IOS 5.1.1 with Tiny Umbrella, then as you are on IOS 6.0.1 you can downgrade without any errors on iTunes, after all, the problem of the greyed out wifi started with IOS 6.0.1 so why not downgrade back to IOS 5.1.1 which was basically the best OS update. Not only will this fix the "wifi greyed out" problem, but you will be able to downgrade back to IOS 5.1.1 whenever you want.

Buddy of mine called me with this same wifi issue on his 4S. I had no answers for him. He called me back about 30 minutes later and said that he did 4-5 hard resets in a row and it came back on. Seems like a iOS issue to me.

Hey bud, this is a major IOS 6 bug that many people are going through. Apple will most likely be putting this problem #1 on their list because it has affected many iphone users. You are just going to have to be patient until IOS 6.1 comes out and the bug is fixed. If the bug is not fixed after IOS 6.1 is updated, then send your phone to Apple and they will most likely replace your phone or fix it. Apple has great customer service so I wouldn't be surprised if they replaced your phone for free. This issue is huge for Apple and they may lose many customers due to this issue. My advice is to just be patient until 6.1, but if that doesn't work, send your phone back and leave it in the hands of Apple's excellent customer service. Hope this helps.

-Alex

turn of your bluetooh

go to general>cellular> cellular data 'of' >

general> reset> reset netwaork setting...

try this one :-) i hope your wifi will work

My last resort (which I thought was dumb when I read it) was the freezer trick. It actually worked! Put my iPhone in the freezer for 5-7 minutes and then restarted it and my wifi works now.

I lost wifi while streaming music, and couldn't switch it back on. I tried everything written here. I talked with my carrier and made a genius bar appointment. Then it dawned on me....maybe it was the app that caused the problem. I deleted the app from the phone and did a hard reset. Whamooo! Wifi back up and running! I reinstalled the music app and everything is functioning as it was. Hope that helps and the freezer thing is a myth...

Have you try this way?

Continuously reset network settings for 5 times.

Settings-General-Reset-Reset Network Settings-Reboot

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