Headphone jack seemingly screwed up

I have a Sony Vaio VGN-N365E. When I plug headphones in usually I can only hear audio on the right side. When I press down on the plug that's in the jack, the left side works and it sounds normal. When I release the downward pressure it goes back to only the right side again. I thought it might be the headphones causing the problem, but it's not. I tested another pair and the same thing happens. It's seems to be some kind of hardware problem. Does anyone know what kind of parts may be the culprit? The headphone jack, microphone jack, and usb connectors seem to be all attached to the same thing because they all move when pushed. Would this be something that I would need a professional to work on or could someone with little to no computer repair experience do the job? This thing is frustrating. Thanks