I know this problem has been stated before, but none of the solution worked for me. I'm running Ubuntu 14.04 on a Asus U32 laptop, alongside Windows 8. Recently I've updated from 12.04 to 14.04 and the wifi can't be enable now. Before upgrading, it worked perfectly. I have no hardware button to switch it on/off, so it must be software related. On windows 8 the wifi is working ok.

I've tried Fn+F2 to enable it, but it also goes on for about 1 second. Also, I've tried the rfkill unblock command in terminal, but nothing.

I don't know what else should I try.