I have seen similar problems on this site and on others, and I have tried all sorts of solutions posted, but so far non have worked. I have a Toshiba Satellite M115-S1061 that came with Windows XP. I want to learn Linux so I installed Ubuntu 12.04 LTS and the sound isn't not working correctly. It worked fine on Windows XP beforehand. I have also tried Linux Mint on this machine with the same results. I can very faintly hear sound if I plug in headphones, but nothing comes out of the speakers.
When I open the Sound Settings, there is nothing listed in the Play Through box under the Output Tab. I click "Test Sound" and nothing happens. Under the Applications Tab it shows ALSA plugin [plug-in container]. The volume for that is all the way up, however, at the bottom of the window it says Output volume, and that's all way down and I can't adjust it.
I have no idea how to solve this and I really would like to have sound coming through the speakers and more volume coming out of the headphones.