I have a HP dv7-1285dx, and I don't really use headphones that often on my laptop so when I recently did use them I discovered that sound only comes out of the left ear piece. The sound on my latop works fine, i have tested it and both speakers display the *bing* sound during windows 7 sound test, however, with the head phones plugged in there is no sound in the right side of the ear. I have tested up to 4 different headphones and the problem is still there. More than a year ago I sent it in to HP because according to them the motherboard needed to be replaced, maybe they took it out and didn't reinstall it/it's loose or something like that? Any ideas on what I can do to fix it?