My 17" MacBook Pro all of a sudden today decided to turn on the digital audio out. If I plug in headphones they work, but if I unplug them the red light comes out of the headphone jack and I get no sound. In the sound section of System Preferences I cannot even select internal speakers as an option, they aren't there. Can anyone offer any ideas on how to fix this? I'm not even cool enough to have any digital audio equipment.