So I am reading these two posts, that sound very smart and reasonable: here is the first one
darkstar49
Same problem for me on iPhone 4S... Everything 100% fine, 6.1.2 upgrade, no more WiFi, no more Bluetooth...
Tried everything (excepted the hair dryer...), no success.
Apple's attitude is just scandalous given the sheer number of complaints !!!
I've spent quite some years writing embedded software and device drivers (in the industry and in the aerospace areas), just greying out the WiFi button is plain stupid, some usable error message and/or message in some error log is really the minimum one can expect from professional developers !!
Wake-up Apple developers !!!
Just imagine the iPhone 4s would be the heart of a plane's flight computer !!! No one would fly Apple anymore !!!!
Sound stupid to you ?? Don't think so... this is the kind of question any serious developer should ask to himself...
If Apple thinks they can further succeed while ignoring their customer's problems, and gambling with quality... they're wrong, so wrong they can't even imagine...
and here is the second:
darkstar49
Although Apple is not likely to admit this before the end of times, this issue is clearly linked to a bad soldering of the BGA casing of the WiFi/Bluetooth IC.
All the symptoms, as well as many successful reballing attempts (i.e. reflow of the BGA) confirm this.
The problem is that very, very few people are properly equipped to reball such an IC, and the outcome of trying it with DIY tools (hair dryer, thermal gun...) is pretty random (with a high probability of failure !!).
This can be clearly classified as a "hidden defect" (i.e. one that was present already at buy time), which should be covered (in many countries, at least) much longer than the ridiculous standard Apple warranty of one year (which btw, is illegal in many countries !).
I'm going to give it a last try with Apple here in Belgium, with very little hope... But if they don't fix this, it clearly was my last Apple device...
I've had many issues on german cars in my life, which were mostly repaired for free, although the warranty had expired (sometimes since years), so if a company wants to sell in the (very) upper category, it MUST provide the according service level, otherwise, it's called robbery...
First one tells me it is a software problem, second it is hardware problem. Which one is it?