Successful solution to the problem of ubuntu14.04 system without sound

ubuntu14.04 System, no sound.
If your computer has a graphics card, there are HDMI, the Ubuntu system may not automatically select the board above the sound card, so, in the configuration with a command to allow the system to automatically select the motherboard above the sound card. The method is as follows: Open the terminal and copy the code to run:
sudo gedit/etc/modprobe.d/alsa-base.conf in the pop-up window, the last line to add and save:
Options Snd-hda-intel Model=auto also reboot the sound card module:
Sudo/sbin/alsa Force-reload
Enter the command two times, perform two sound card restart, after the completion of a sound.