Howdy, My name is Kart. I just bought a brand new 17 MBP and have been listening to music on my MBP with my nice new SkullCandy Rocnation headphones and have been truly enjoying that. But to my dismay the headphone jack stopped working on my Mac. (I've tried several other headphones as well.) You plug in headphones and music continues to play on the machines internal speakers. In the system preferences under the output section I don't even have a option for headphone jack. All that is available is Internal Speakers and Display Audio from my Thunderbolt display. It's really driving me mad. It's as if someone went in to my system settings and deleted the headphone jack output drives, if there is such a thing. Any ideas as to what might be the problem? Thanks for you time and help.