I was listening to music on my headphones and when I turned around to grab my cell phone I accidentally put too much pressure over the plug, so now I can only hear sound from the left channel. I'm going to take the MacBook to an authorized service provider on Monday. Does anyone know if it is possible for them to replace only the headphone port or is it necessary replace the logic board? (I bought a brand new headphone and the problem remains, so it is a problem with the port. Also, looking inside the port, I noticed that the top metal contact is slightly higher than the one inside the line-in port.) Thanks a lot.