Hi all
FYI i am a victim of this issue, i have try all the hot/cold and it works only few days. i even go to Apple shop, they said since i am out of warrently, i need to paid USD280 for replacement.
I ultermately go to a local shop to do a reflow and now everything is ok.
I heard that this issue is normal for iphone 4S, it happen since IOS 6.1.4
no one know the actual course, it just specaluate that it could be the soldering is not robus enough and when there is suddent hot/cold, it will make the soldering brittle and easy to break.
If you all know/experience with ios 6.1.4. and ios7 on iphone 4S, you all should know that it get very hot easily even just doing FBing for 10 minute as compare to iphone 3 and iphone 5.
Basically what i am saiding is that i believe/think the cause is phone hardware itself, but the catalyst is IOS 7. If you all take note of ios 7, it switch between 3G and wifi very frequently (never have it so frequently on ios 6.1.4)
With this i would suggest to forget about the cold/hot treatement as it may not last long, try to paid a little(i paid USD64) for the reflow. i believe it will last more than one years, depend on the quality of the reflow.
And if you have an iphone that its warently about to expire, get it change with apps store, just said the wifi/bluetooth intermitten offline. At least i believe the referbish piece will last another oneyear or more.
I have said me piece. Hope it helps. So forget about apple, its of no use arging, they will never help you and they will definately never going to admit that their Iphone 4S is of low quality and wil never recall like Toyota, unless iphone get exploded. 😐
I found this in the internet and somehow i agreed reflow is the solution.
http://www.ifixit.com/Answers/View/129316/Dead+wifi+(greyed+out)