Just the other day I connected a pair of earphones to the audio line out port of my MBP. The levels were not the same...sobrang hina nung left side. At first I thought it was the earphones so I got my studio reference headphones and tried it. Same problem. Tried to move the jack around...and it seems like the contact inside the port for the left side is the problem. Is there a way to clean it or do I need to have this serviced? thanks!