Alienware 18 - Speakers Stopped Working

My speakers spontaneously stopped working on my Alienware 18 today. I didn't do anything special, like install new programs. Sound comes in properly through headphones still.

There's no longer any sort of popup saying I'm unplugging or plugging in my headphones when I do so. As best I can tell, it seems to think there are headphones perpetually plugged in. I checked for foreign object in the jacks, and even blew some compressed air in to try and dislodge anything I couldn't see, but there was nothing. Rebooting has no effect on the issue.

I was having an issue prior to this that I figure I should mention in case it sheds light on what happened: After a bit of use, the high-end sound would become muted through the speakers. It seemed to be triggered by me putting pressure on the chasssis, usually by typing on the built-in keyboard, or sometimes just by putting a bit of pressure on the palm rest. It would be fixed temporarily by plugging in and unplugging some headphones into the audio jack. I bought a separate keyboard in the last month and have been using it the majority of the time, so that issue hasn't surfaced for a while.