Audio problem dv6128ea. Only play headphone sound, not on the speakers

Hi

I have a hp pavillion dv6128ea.

I installed windows 7, and now I only have sound with the headphones. Speakers don't play any sound.

I have tried many solutions found in this forum but none of them work.

Someone can help me?

The sound card is a Conexant cx20549 @ intel 82801 gbm ich7-m 

Thanks