Suddenly, a Macbook running OSX 10.6.8 started complaining that there was “No airport card installed”.
I googled a bit, and found that it might have been a hardware malfunctioning. In some other cases instead, people reported such a problem after upgrading to a new version of the OS. Some people suggested trying a PRAM reset and other techniques, but they all failed with me.
So I thought it was really a hardware problem. Luckily I had a spare Macbook – with a working airport – and I decided to swap the disks. SURPRISE! the airport of the spare Mac stopped working, while the one of the supposedly damaged one was fine!
So, the problem was with the disk – or better – with the disk content. In other words, the OS had a problem! So I reinstalled a fresh copy of Mac OSX 10.6, upgraded it to 10.6.8, and the problem was fixed.