HP pavilion dv-5 sound problem

Hello,

I have a HP Pavilion dv-5 1102tu laptop. Running on Windows-7 32bit OS. Until a few weeks back both the speakers and the headphones were working perfectly. Suddenly they just stopped working. The device manager says that the speakers are fine and I also installed the drivers again. Yet, both the speakers and the headphones do not work. The touch button to mute and unmute the speakers flickers continuously. Is this a problem with the sound IC or a software problem. Any help will be appreciated. Thanks