those little 3.5mm connections break all the time, I presume you've tried a different pair of headphones to make sure it's the case connection rather than the headphones, right? If it is, well I'm afraid you'll have to either get a new case or a new panel, depending on your Sound Card. You should get a new panel for $15 or less. But if you're pretty adept at soldering you can make a new one or wire up a female connection for a couple of dollareydoos no hassle. Most electronics shop will have a female 3.5 mm jack connection (harder to solder) or a cable (much easier) which you can recess into your case, but it may not fit properly.