sound suddenly stopped working after update

File a bug and report this issue. Give information about your system when you do that.

Use the older kernel until someone knows how to get sound working on your computer.

Please be sure all needed kernel modules are installed to make this check and install them:
So open a Terminal from the menu Applications->Accessories->Terminal and type:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install linux-ubuntu-modules-$(uname -r)

give your user password when requested, you don't see nothing when you type it, then press enter.

Then reboot your pc.

Hi
When I type the above I get:

:~$ sudo apt-get install linux-ubuntu-modules-$(uname -r)
[sudo] password for dumpa:
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package linux-ubuntu-modules-2.6.25.9-ultimate

I think this is your issue is because your installed Ubuntu is ultimate Ubuntu that use a no standard Ubuntu kernel for more info http://ultimateedition.info/

Hope this helps

It is the first time I hear about an Ultimate edition. How did I end up with an ultimate edition I don't know.

What should I do then?

Have you some old kernels to select at boot by pressing ESC when you see the GRUB row...?

If you have, then select an old kernel and boot from that...

Has you sound come back..?

Have you put into /etc/apt/sources.list some ubuntu-ultimate repositories reference...?

http://repoubuntusoftware.info/

Is there are some please rem them.. put a # in front of the row.

Open a terminal and type:

sudo gedit /etc/apt/sources.list

give your password, press enter.

Make your check/changes then save then type:

sudo apt-get clean all
sudo apt-get update
sudo apt-get upgrade

Then you must remove the unwanted kernel.

Please give me some info.

Thank you

Hi, thanks for the answer.
I booted with the previous kernel and the sound works.
I don't see any of the repositories for ubuntu ultimate.
How can I remove the last kernel?

here is a list of the repositories in case I missed them:

  # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

deb http://co.archive.ubuntu.com/ubuntu/ hardy main restricted
deb-src http://co.archive.ubuntu.com/ubuntu/ hardy main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://co.archive.ubuntu.com/ubuntu/ hardy-updates main restricted
deb-src http://co.archive.ubuntu.com/ubuntu/ hardy-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://co.archive.ubuntu.com/ubuntu/ hardy universe
deb-src http://co.archive.ubuntu.com/ubuntu/ hardy universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://co.archive.ubuntu.com/ubuntu/ hardy multiverse
deb-src http://co.archive.ubuntu.com/ubuntu/ hardy multiverse

## Uncomment the following two lines to add software from the 'backports'
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
# deb http://co.archive.ubuntu.com/ubuntu/ feisty-backports main restricted universe multiverse
# deb-src http://co.archive.ubuntu.com/ubuntu/ feisty-backports main restricted universe multiverse

deb http://security.ubuntu.com/ubuntu hardy-security main restricted
deb-src http://security.ubuntu.com/ubuntu hardy-security main restricted
deb http://security.ubuntu.com/ubuntu hardy-security universe
deb-src http://security.ubuntu.com/ubuntu hardy-security universe
deb http://security.ubuntu.com/ubuntu hardy-security multiverse
deb-src http://security.ubuntu.com/ubuntu hardy-security multiverse
# deb http://ftp.osuosl.org/pub/pculture.org/miro/linux/repositories/ubuntu hardy/
# deb http://morgoth.free.fr/ubuntu hardy-backports main
# deb-src http://morgoth.free.fr/ubuntu hardy-backports main
# deb http://ftp.osuosl.org/pub/pculture.org/miro/linux/repositories/ubuntu hardy

I'm going to rephrase my previous post since I didn't get an answer and it seems badly written.

When I boot with the generic (i.e non-ultimate) kernel the sound works.

I checked the repositories list and I don't see any ultimate repositories on it. The complete list is above.

I want to remove the ultimate kernel (the unwanted kernel) but I don't know how.

or if not remove it make the computer automatically boot with the kernel that works.

Thanks Isak Frants, that solved my question.