No audio from speakers

Hi, 

I have a Pavilion dv6835nr, purchased in 2008. Lately, there is no audio from the laptop when i play music, videos or any system sounds. 

I checked the audio test in the control panel and when i click on the "Test" button for left & right speaker, it plays fine but not when i play any music. 

Product number: KN947UA.

Please advise. 

Thanks

ardent_guy