Hi, i was just listening to itunes on my macbook when all of a sudden i heard a loud pop, and the music stopped playing, even though itunes showed the song to be continuing. i can't her any sound on my macbook now regardless of the sound volume being high or low. also, whenever i press the on/off volume (f3) button, the same pop noise that i heard earlier sounds. any ideas on what could have happened?!!? i have not dropped the macbook or damaged it recently as far as i can remember... thank you!