Sound Problems

I have Windows Vista installed on my HP Pavillion laptop. A few days ago, sound through my headphones stopped working. That is, sound is played fine through my computer, but now when I try to plug in headphones, it's as if the headphones are not there. My computer is completely ignoring that I have plugged in headphones. It keeps on playing music through the regular speakers. I've tried different headphones but nothing has changed. I've never had a problem with listening through headphones on my computer before, this only started happening within this last week. Is there anything I can do to? A setting I might've accidently changed? My one year warranty for this laptop is ending very soon...

 

It sounds like the jack for the headphones may be damaged. If the speakers are working that means there is not a problem with the sound card.