no sound after updating.

[anandacj]

hi i am new to ubuntu , i installed ubuntu 10.04 and after installation it had automatic updates i did that updates ter wer around 150 updates after these updates the output sound is gone.
can anyone help me out wid this problem.
it is detecting my sound card and its not muted in alsamixer.

[anandacj]

now i restarted my system and i had sound for around 20 seconds and then sound goes off. can anyone help me in this matter . Thanks..