MacBook Pro WIFI hardware problems

I have a late 2011 MBP (MacBookPro8,1) and for the past 6 months I have been having trouble with the WIFI randomly turning off and then not being able to be turned back on until I restart the computer (and even then it still sometimes will not work). In these instances, if I press the "Turn WIFI ON" button nothing happens at all.

What I have tried so far (the problem persists through all of it)

1) reset routers and tried on different networks

2) upgraded my OS from 10.7 to 10.10

3) replaced the internal airport card

4) reset PRAM and whatever other things people suggested to reset in online forums

5) different combinations of deactivating WIFI, deleting it, restarting, re-adding it reactivating it, etc...

Correct me if I'm wrong but it seems like this must be a hardware problem that is something other than the internal wireless card (I replaced it).

I do not want to replace my MBP yet so any thoughts or help would be greatly appreciated. Thanks!