Problem: Wifi turns itself on automatically and drains battery. You've tried the firmware update but it does not solve the wifi problem - this is the hands-on hardware fix.
Here's a how-to and it works. Please read all description and even the comments below...
(Note: WIFI on = flashing blue light.)
The wifi button covers a switch which is prone to failure (wifi turns itself on automatically).
This video shows how to remove the wifi switch from the circuit board and prevent wifi turning itself on and draining the battery. If you still have warranty with your GoPro purchase please consider first taking that route instead.
Note, in this video the switch has already been removed and I show you how to get to it and how to remove the switch.
Sorry this video's not shorter - on the plus side you should have enough reference here. (I also had a cold and was very run-down when filming, hence a somewhat sleepy delivery in places. Sorry about that.)
Proper firmware update directions should be tried first - note, there is a particular way of upgrading the firmware that has a better chance of working for you (manual). My video is for if the firmware upgrade did not work for you (as was the case with my GoPro).
UPDATE: Guys please check out micke240sx' comment below, he's figured out achieving the same thing but without taking the thing apart, more of a local surgery. Well played mate! :)
Here's his pic: http://instagram.com/p/nk6Z93CLSM/ - you may want to watch this vid also for reference.
Good luck!
