Basically, here is how things progressed.
1. Headphones plugged into jack worked.
2. Headphones plugged into jack occasionally stopped working, but worked when I restarted the driver.
3. Headphones do not work when plugged into the jack and restarting the driver does nothing.
I am currently using Windows 8.1, a Realtek soundcard and drivers, and the headphones are not defective. Strangely enough, the headphones are "noticed" (there is a popup in the Realtek HD sound manager where it asks what you are plugging in) when I put them into the jack, so I'm somewhat sure the jack isn't defective. Any ideas what could be the issue?
Edited by cthulhusquid, 10 February 2016 - 06:05 PM.