[Ubuntu Wiki] Update of "DebuggingSoundProblems" by markrijckenberg

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The following page has been changed by markrijckenberg:
http://wiki.ubuntu.com/DebuggingSoundProblems?action=diff&rev1=59&rev2=60

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     * [[Audio/CheckForMutedMicrophone|Check for muted microphone]]
  
  == Checking volume levels ==
+ 
  Before messing around with uninstalling and installing various sound programs to fix a problem, check your volume levels.  It is often the case that a muted channel is the problem, even though the description may not sound immediately relevant.  In this regard, muted Surround or Center channels are common culprits. So unmute and raise the volume of one channel at a time and check whether sound is then produced by a running sound application e.g. Rhythmbox.
  
  You can access the volume levels for the various channels from the command line or the GUI.
@@ -36, +37 @@

    * Starting with Ubuntu 7.04, the sound volume control is also accessible from Menu->Sound&Video->Volume Control. It may be hidden in your menus but can be shown by going to System > Preferences > Main Menu and under Applications > Sound&Video ticking Volume Control.
  
  == Checking sound device assignment ==
+ 
   1. Most sound applications output to card0 by default. In some cases, other audio devices (like a USB MIDI Keyboard) might be recognized as a soundcard and take card0, bumping your real soundcard to card1.  To see which devices are connected to which cards, do the following: 
    * {{{
   cat /proc/asound/cards
@@ -47, +49 @@

  The index numbers (0, 1, ... 7) signify the priority of the device, with the highest priority device being 0, then 1, and so forth.  In theory, applications should first attempt to use the highest priority device first, but if for some reason the application is unable to use the device, it will use the next highest priority device.  For example, if you have a USB sound card that can get picked up with OSS, which browsers, flash, and skype may not output, if you set your USB card at first priority, it will play when using, say, Rhythmbox, but your other applications will play through your other soundcard.  FIXME PLEASE: for more information go to the ALSA-Configuration kernel document.
  
  == Checking permissions and resources ==
+ 
    1. Make sure that all users needing access to the Sound Device can "Use audio devices" in the "User Privileges" tab of users-admin (System->Administration->Users and Groups).
    1. Test different "Sound Servers": Go to System > Preferences > Sound ("Multimedia Systems Selector" in earlier editions of Ubuntu). From there, you can test the different options. In some scenarios several different sound servers may be installed, and only one may work. This is probably the origin of the problem if you cannot play audio with xine or rhythmbox, but you can with xmms or helix/realplayer. 
    1. If you application sounds works, but your system sounds does not (login, logout, error sounds...) try removing the .asoundrc* files from your own directory (e.g. with 'rm .asoundrc*'). It should make the system sounds work without a reboot.
    1. If you can get absolutely no sound and you have an onboard sound chip you can try to disable it in the BIOS. This solves the problem is some cases.
    1. If you have no sound and you have a regular sound card type "lsmod | grep snd" in the terminal and see if there is more than one card listed.  It's possible that you have a motherboard sound chip that is interfering.  Add it to the bottom of the blacklist file.  For example, sudo nano /etc/modprobe.d/blacklist then add "blacklist snd_via82xx" to the bottom. 
- 
  
  = Reporting Sound Bugs =
  
@@ -85, +87 @@

   * Do not mark bugs as duplicates unless you're 100% sure that both the '''hardware''', '''software''', and '''symptom''' match exactly. Slightly different hardware very often requires slightly different fixes. If in doubt, file a new bug.
  
  === Identifying your hardware ===
+ 
  If the output of {{{lspci}}} includes a line similar to {{{00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03)}}} (a High Definition Audio device)
  
  Please paste the output of the following command at the top of your bug description:
@@ -103, +106 @@

  
  If you are about to file a driver bug (e.g., absolutely no applications output sound, microphone does not work even after toggling nocap, speakers continue to emit sound after headphones have been inserted), and you think that you see a bug report that matches your symptoms, '''STOP''' and check the bug's attachments to see if these 4 bits of data match.  If all four match '''and''' the symptom matches, subscribe to the existing bug.  If '''any''' of the 4 data points disagree, you probably have found one of the myriad cases where many different bugs with different root causes that need different patches have the same symptom on the surface.  In which case: '''file a new bug.'''
  
- 
- 
  = Further sound troubleshooting =
  
  After reporting a bug you might want to see the community documentation:
+ 
+  * https://help.ubuntu.com/community/SoundTroubleshootingProcedure
   * https://help.ubuntu.com/community/Sound
   * https://help.ubuntu.com/community/SoundTroubleshooting
   * https://help.ubuntu.com/community/DebuggingSoundProblemsMisc
  
- 
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  CategoryDocumentation  CategoryBugSquad CategoryDebugging