No sound from speakers ! Mono sound from headphones

Hello. I do not receive any sound from speakers on my hp pavilion 6397ea laptop. When I plug in my headphones I can hear the sound, but only in mono. I tried everything, downloading new drivers, using a system restore...Seems like the sound card is on its deathbed, breathing just from one lung and so silently that you can hear it just from your headphones...Well back to the issue, the soundcard must still be working, because I hear mono sound from my headphones. It is strange. Any ideas ? Many thanks for your help...