Currently Being ModeratedFeb 8, 2013 1:45 AM (in response to erickgeshan)
Does the power adapter charge properly, and the LEDs illuminate as they should? If not, the power adapter probably needs to be replaced. Internally, the power adapter contains a couple of small transformers. Depending upon the load, and the tightness of the transformer plates, the plates may vibrate audibly. It may behoove you to schedule an appointment with the Apple Genius. Be sure to bring in both your computer and power adapter, and allow the Genius to evaluate the situation, and offer a recommendation.