Ubuntu is waiting for a response from the sound system.

First, try entering the command in the terminal: sudo/sbin/alsaforce-reload to drive the sound card again. [system]-& gt; [System Management]-& gt; [New Software Package Manager] Click the [Search] button to find all packages starting with alsa. In addition to retaining alsa-base, all packages are completely deleted. restart the computer and the sound is restored. (Ubuntu9.10 and 10.04 can be solved in this step.) At the end, if the above does not work

First, try to enter the command in the terminal: sudo/sbin/alsa force-reload to enable the sound card driver.

Again, [system]-> [System Management]-> [New Software Package Manager] Click the [Search] button to find all packages starting with alsa, except for retaining alsa-base, delete all items completely. restart the computer and the sound will be restored. (Ubuntu 9.10 and 10.04 can be solved in this step)

Finally, if not, click the [Search] button in the [New Software Package Manager] to find all the packages starting with pulseaudio, delete them completely, and restart them;

Note: The side effect is: open [system]-> [first item]-> [sound] will show "waiting for sound system response",

The Gnome ALSA mix is required to adjust the volume: sudo apt-get install gnome-alsamixer