Are you sure this is not your headphones? I've had many pairs that went bad from tension being put on the jack. Make sure they are "stereo" headphones, if you're using monophones then you will only get sound in one ear no matter what you do. Or try plugging in external speakers. Anything to rule out the headphones, and making sure that you are using a compatible pair. If not, then you should try powering down your Macbook, reset the PRAM/NVRAM. If that doesn't work, then try powering down, unplug then reinsert your headphones while it's off, then power it up and see if they are working, this is a typical fix for older macbook pros. If that doesn't work, go into your system settings and click on audio, make sure your software is set to "stereo" and when you insert your headphones it switches to line out under audio output. If that doesn't work, and you're positive it's the audio jack, remove the bottom cover of your macbook pro, check to ensure the audio jack has not been broken loose from the logic board....

This is not a huge deal. I just accomplished this feat in less than 30 minutes with a $30 investment in a micro solder tip for my iron and 0.015" solder. You just have to have a little confidence and a little patience. If your fan connector breaks off, DO NOT PANIC! You do not need a professional. If you're looking for help on this site, then most likely, you have done small repairs before. So, here is what I did, and I believe if you found this column, you can probably do it to. 1. Take the bottom cover off your Macbook Pro. 2. Using a set of helping hands, I clipped the edge of the fan connector in the tip of the alligator clips, and positioned them directly where I needed the fan connector on the board. If you have a decent set and play around with the positioning this should not be a huge deal. 3. Make sure you have a solder iron with a micro solder tip attached. This will look like a bent tip that comes to a needle point. They can be found at radio shack, that is where I bought mine this morning. 4....