I wonder if anyone can help with this. From time to time I can hear a very faint buzzing noise coming from the back left of the notebook, right beside the magsafe connector. The noise only seems to happen mainly when I leave the MBA lid open and let it go to sleep. The noise will start when the screen goes dark and as soon as I touch a button or the trackpad it stops and the Air wakes up and works fine. The noise also happens if the charger is plugged in, and if I move or disconnect the charger the noise stops?? Now I'm sure its not the fan as I've heard that get loud during use so I know thats a different noise, and also the fan has no reason to be on when the notebook goes to sleep. The MBA has been working perfect since last July when I got it but the noise is really annoying. Anyone have any ideas what this could be? Specs: 13", i7, 8GB RAM, 256gb.