Veiw this Topic in the How To : viewtopic.php?f=42&t=32293
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Or just search for your Laptop Mod
More than likely you Will have to modify the file ( root/etc/modprobe.d/alsa-base.conf ) On most laptops I have installed to, the sound driver is not configured to work with the hardware, but with modification it will work in most cases.
1) For the excact modification for your laptop, try searching ubuntu fourms ( http://ubuntuforums.org/
) with your laptop #, make & model as well as " No Sound " in the search line. Ex: TOSHIBA TECRA No Sound or Ex: Hp Pavilion dv4 - 1275 no sound
2)If You Find multiple or similar results for your laptop , try to narrow the results by model# or Hardware Specs. I would suggest reading all that apply before making any changes to your ALSA Base.If you can, make a copy of your alsa base & save it to your Docs, In case you mess up.
3) Not every mod to the alsa base works for every type of hardware, if you find an excact match it is best, but if you can't , use the closest results. Read the Entire section Before you Modify your ALSA Base & back up if possible .
If The Mod Fails you can read the " Comprehensive Sound Problem Solutions Guide " found here ( http://ubuntuforums.org/showthread.php
? ... A+No+Sound )
Hope this points you in the right direction,