if found this tutorial of how to fix the wifi firmware bug the unconventional way. its not your hardware its the IOS upgrade on 4s. this video explains and show's how to fix WiFi being grayed out.
The method works for some people, but there is no way in the world that heating a device fixes a SOFTWARE problem. Heating changes hardware, not software. Further, this problem has nothing to do with 7.0.4. The SAME problem has been reported with ALL earlier versions of iOS, as a browse through the forums will easily prove.
I didnt buy the warranty, but the youtube video i posted up there worked for me without fail yet.
although i agree with Lawrence Finch, it does not work for everyone. and its at your own risk as the video reiterates.
I've posted before that I had the same issue after upgrade to IOS7
My wifi, however, was not greyed out, but could not pick up any network.
After Apple were extremely unhelpful, I took it to a repair place in Australia and they resoldered something to do with the wifi.
All was working well until, and I don't know if this has anything to do with it, but I updated to Mavericks on my laptop, plugged my phone in to sync some music, and after unplugging my phone the wifi was once again not working.
I've given up on it now.
I spent so much time on trying to get this to work, as well as money to have it fixed.
Good luck to everyone else.
I have a 32gb verizon Iphone 4s running 7.0.4 .My Wife's AT&T 4s is running 7 though she has not updated to 7.0.4 and has had no wifi issues. Well I have been trying for over a week to fix my greyed out WIFI button (did nothing no matter how many times you touched it) under settings. I have tried all the recommended apple solutions reseting network settings, reinstalling ios under itunes, airplane mode on with network reset you name it. Nothing has worked. I only have 500mb of data under pagepluscellular and found out a week ago I chewed threw all of that in 2 weeks oblivious to the fact my wifi had died. Finally went downstairs in my house and roasted my 4s in front of the pellet stove vents till the DANGER OVERHEAT or whatever that message is came on the screen. Have never seen that message before. Threw it in the freezer for 15 minutes and wifi has been working fine since. Bizzaro.
I too have had the same problem with my wife's 4S, tried the hairdryer heat it up trick and that got it working to at least download IOS 7.0.6, but overnight it reverted back to same problem, O2 want her to upgrade early, at a cost of £178, the phone's warranty has expired, Apple will not admit that a update has caused it to go wrong and instead insist its a hardware problem, utter crap and a fobb off ! I will be sugesting to all,frinds and family to change to a Droid like the Samsung Galaxy. Unless Apple come up with another update that fixes this problem
Sorry, but I agree with others that this is a hardware problem. You don't fix software with any of the fixes that seem to partially work. Also when the wifi is greyed out the battery life is rubbish, which says to me that the software is trying to start the wifi chip and failing.
The Apple store, rather than your mobile provider should give a less expensive 'fix' than the mobile provider, I've been told that as a known fault they are obliged to make a reasonably priced solution, although I haven't put that to the test yet (currently mine is working following the remove sim and crash start fix, but it won't last).
And android phones typically last 12 months before giving loads of problems, so don't run there for reliability, but by all means do so for features.
Just an update. 10 days after pellet stove / freezer
treatment wifi is still working fine. Yes battery life was
crap when it was greyed out . Could not
even make a day of light use with
mophie juice pack case. Now 2 days. Talking
to a former PC tech . They used stove/freezer
method to restart dead disk drives
and recover data. Yeah must be a
hardware issue and rearranged something
This has been annoying me and have suffered it for 6 months. No wifi, sometimes it'd be greyed out too. I tried everything. This included putting it in the freezer and nothing helped. I then thought about why it isn't working and looked into what makes an iphone overheat. Location services!!! So I went into settings>Privacy>location services>system services and turned most of them off. None of which effect the phones performance. Magically after letting my phone cool down and on full charge Wifi now works 99% of the time. I agree it's not ideal but it has worked for me, so I hope it works for someone else.
After several tries, nothing worked.
The fact is, that my iPhone was working fine (it even quit giving me problems while roaming!). Since iOS7 upgrade wifi gives problems.
Apple refuses to recognize a defect and warranty.
I will send it back to Vodafone for a repair , this means not using a working tool for 3 weeks at least (not to mention waste of time).
Looking forward to end my contract with Vodafone in few months and get rid of this crappy phone.
Definitely, my experience with 4x iPhones (previous iPhone 4 with home button problems) has been a disaster. The worst hardware I ever had.
After having my iphone 4s for over 2 years with no problem (on ios 5), I made the decision to update to ios 7 about a month ago. Very poor decision.
On the first few weeks the only major problem I had, was that my location services were useless. None of the map and gps apps I had couldn't locate me, let alone direct me somewhere.
A few days ago out of the blue, my phone stopped discovering wifi networks. It is not greyed out, just not discovering any network. Tried numerous different places, tried every trick available (except for the freezer trick), updated to ios 7.0.6, but to no avail.
I'm having a hard time realizing if this is a hardware or software issue. It seems obvious that this a software issue, but if the freezer trick works for some people than it might be hardware I guess. My next is going to be a battery/wifi antenna replacement and checking to see if any of them solves it.
Hope someone finds a fix for this issue, a smartphone without wifi is not so smart, and having a 700$ worth of stupidphone is very irritating.
I will update, and will stay updated on this thread.