I've had my macbook pro since May of this year and the headphone jack have always worked. Recently my mom has brought two kittens into the family. Your probably asking yourself what do kittens have to do with this problem. Well every time I open my laptop when the kittens are by me, they instantly start walking across my keyboard and accidentally hit buttons. They had to have turned something off because when I plug headphones in the side of my laptop, the sound comes from the main speakers, not the headphones. Can someone please help me?
Yeah, and I've tried to keep them off. I think it was just the set of headphones I used, because I put a better pair in and it is working. The headphones were the ones that came with my ipod, I don't know why those wouldn't work. Oh well.
I did the same thing and gave myself a scare, didn't even have kittens to help me. In the sound category of your system preferences there's a drop down menu marked "Use audio port for". Switch it so it says "Sound Output".