I have done almost all the solutions that I could find! i.e. reinstalling pulse-audio and alsa-base, playing around with alsamixer, etc. But couldn't make it work.
My audio card is "Integrated: Realtek ALC269Q High Definition Audio".
In System Setting > Sound, I see three drivers: HDMI/Display port, Speakers, Analog output. Non of them produce any sound. This is a fresh install of Ubuntu 14.04.
alsa-info output can be found here. Please let me know if you need other logs, info...
P.S. There is another similar unanswered question here.