My Magsafe adapter for my Macbook Pro all of a sudden stopped working. It's no longer charging my MBP. I've noticed usually when charging my MBP if i listen to the adapter it will give the sound like very small motor or gears are running. Now it just sounds like a long beeping sound. I was wondering if this is some known defect, because I made an appointment with the Genius bar for tomorrow and from what I have heard Apple is known for replacing defected parts even if they are out of warranty.