I have a MacBook Pro mid-2012. I always had the common connectivity issues with wifi but now its beyond my comprehension. My wifi turns itself off randomly. Sometimes it works fine for days, other times the problem happens all day. It started when my Bluetooth speaker caused interference with the wifi signal causing it to run slow or disconnecting itself either the speaker or the wifi.
Then one day the computer wifi started turning itself on and off every couple of seconds. I shut down the computer reseted the PRAM then wifi showed the crossed out icon with wifi:not configured message. Shut it down again did a SMC reset and a clean install of OS X now the problem appears randomly most of the time a reset will restore wifi but it shut itself off whenever it wants.
Any solutions or ideas?