No sound Pavilion DV9000 (OS Vista)

I have the problem that the sound of my Pavilion DV9000 (DV9337eu) is not working. I have installed all the driver new, but there is no chance to hear anything. If i look in the settings of the sound i can see that it should works. If i connect an external speaker, i can also listen nothing. If i use the top components buttons for adjust the speaker level i hear by each using the beep. This means, the speakers are working propper. Is there an problem with the sound board? Can i change this, or is it onboard on the mainboard?

Can somebody answer me how i can solve this problem?