Comment 7 for bug 647970

Hi langmarp, you could try modifying the alsa-base.conf

In terminal, type: sudo nano /etc/modprobe.d/alsa-base.conf

Add the following 2 lines at the end of the file, save and restart.

alias snd-card-0 snd-hda-intel
options snd-hda-intel model=auto

after this change, sound playback now works fine on my Acer 4930 using Ubuntu 10.10. Since you have a different Acer model, your results might vary.

If this doesn't work, try changing the value of model to 'acer' instead of 'auto'.

If nothing works, you might try installing the fix mentioned here

https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/617647/comments/27

Though I did have any success (Acer 4930), folks having Acer 7736G reported positive results after installing the above mentioned fix.