I am using ubuntu 10.04 LTS desktop and I don't have any sound output from the built-in speakers in my Dell N5040
You need to edit this file /etc/modprobe.d/alsa-base.conf and then add a line in its end.
Use the following commands in a terminal
Now add the following line at its end:
Now reboot your computer. It should solve your problem. If the solution doesn’t work it is likely that the term model = generic may not work in all the cases as sometimes it depends on the model of your sound card.
Find your sound card by typing
You can try replacing the word generic by the following words depending upon your model of Dell laptop: