http://www.kernel.org/doc/Documentat...dio-Models.txt and search for "ALC662" . Find the right model for your laptop.
Then replacein the following codeCode:laptop_modelwith the model of your laptop you just found from the link above and add it to alsa-base.conf. Reboot your system.Code:options snd-hda-intel model=laptop_model
Try using different models under ALC662 in alsa-base.conf until you find the one that works for you.
You can edit alsa-base.conf using commandCode:sudo gedit /etc/modprobe.d/alsa-base.conf