I installed Mint 14 yesterday on my Dell XPS M1530, and at first the sound was working. I listened to music through headphones and the built in speakers, so I know they were working at first. Today, I wasn't getting any sound when trying to play music, so I checked if the system volume was low or muted, then the program, but neither was. I plugged my headphones in to see if it was just the speakers screwing up, but there was still no sound. I rebooted and the start up sound played when I logged in, but there was still nothing when I tried playing music or a video. I'm not sure if this is an issue with software or hardware, but I haven't found someone else who had this issue and posted a solution anywhere.
My skills are limited (but still pretty okay), and any suggestions would be greatly appreciated!
EDIT: I forgot to include some important things. The audio codec is STAC 9228 from what I can tell, and I have only owned this laptop since yesterday (bought it used), so I am not familiar with issues it may have had before. Both the speakers and the headphone jack are silent.