You have to normally log in as user. Open Terminal console, and as soon as you type
sudo aptitude install linux-backports-modules-generic
It will ask you for password for user@
Type password, hit enter, (if asked for confirmation (Y/n) type Y and hit enter
Next command as follows, be sure the letter case, spaces, dots, slashes are all as given:
sudo gedit /etc/modprobe.d/alsa-base
It should open Gedit and it should have instructions, scroll down, and just as if it was any other text editor, as the last line in the file, type:
options snd-hda-intel model=acer
Be sure to SAVE the file, close Gedit, close Terminal, quit, restart, and when it boots next time, the problem should not reappear. Tried twice, same procedure, Ubuntu and Mint, worked both times.
If this is not clear enough, I will mail you, but not today because I'm on my workplace and I'm writing this from Win and both my machines are at home so I can't be more precise or more exact, but if you use just a minimal amount of caution and do not mistype something... My first attempt failed because I typed sudo gedit/ (without space after gedit), next time it failed because I typed it without "etc" and it opened an empty file... So, best of luck, mate and cheers from Subotica, Vojvodina, Serbia, Europe
PS. How did that (c) get into the second line?...
Everything has an end, sausages, however, have two...