Basic troubleshooting

Preliminary checks

1. Is your sound system plugged in and switched on. I spent an hour trying to diagnose a sound issue when the problem was that I had switched off the speakers to answer a phone call and forgot that I had done so.

Checking volume levels

1. From command line: Open a terminal window and launch alsamixer then make sure sound is unmuted and that the volume is turned up. Unmute everything, sometimes a muted channel will be the problem, even if the description doesn't seem immediately relevant.

2. From GUI: This can be done by running something like gnome-alsamixer from a terminal window or navigating to your your Volume Control. Again, at this point make sure sound is unmuted and that the volume is turned up. Unmute everything, sometimes a muted channel will be the problem, even if the description doesn't seem immediately relevant. Also check that your switches are set correctly - for instance that if you use the analog output the analog switch is set ON or that the digital or S/PDIF switch is set OFF. You can select which tracks/switches are visible in Volume Control (see above) under Edit->Preferences.

   • Note: These controls have equivalent functionality to alsamixer but with a graphical interface. Checking or unchecking devices in the these accomplishes the exact same thing as unmuting or muting devices, respectively, in alsamixer.

   • 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

}}}

1. You can manipulate the device number assignment by adding snd-usb-audio to /etc/modprobe.d/alsa-base . Next boot, the snd-usb-audio device will get index 1.
   • {{{ options snd-usb-audio index=1

}}}

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).

2. 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.

3. 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.
4. 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.
5. 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

Please do not report problems on this page; use the normal support channels instead. See http://www.ubuntu.com/support

If you feel you have encountered a software bug, please report the bug at https://launchpad.net/ubuntu/+filebug using your kernel version as the package. If you are uncertain of the kernel version that you have installed you can check by typing uname -a in a terminal. Also, be sure to include the following information to your report. Please be sure to add each file as a separate attachment:

1. Output of 'uname -a'

   • {{{ uname -a > uname-a.log

}}}

1. Output of 'sudo lspci -vvnn'

   • {{{ sudo lspci -vvnn > lspci-vvnn.log

}}}

1. Output of 'dpkg -i linux-ubuntu-modules-$(uname -r)'
   • {{{ dpkg -i linux-ubuntu-modules-$(uname -r)

}}}

• various sound drivers are provided by the linux-ubuntu-modules package

1. Sound Information (see below for how to gather)

Automatic Sound Information Collection

This is the preferred method for gathering the appropriate sound information from you system. It's helps ensure that you gather the sound information correctly and completely. The following script gathers all required information in one go [http://bulletproof.servebeer.com/alsa/scripts/alsa-info.sh] . The script was written to aid the alsa developers, and also to help the people in #alsa to sort out sound issues. Please download and run the script as follows:

1. {{{ ./alsa-info.sh --no-upload

}}}

1. /tmp/alsa-info.txt will be generated. Attach this file to your bug report
2. The alsa-info.sh script can either be run as 'bash alsa-info.sh' _or_ made executable and run as './alsa-info.sh'.

Manual sound configuration collection

This is the information gathered from the automated sound information collection script. We highly recommend you use the automated script when gathering the sound information regarding your system. Manually collection of the information by hand is a tedious process and is more prone to user error.

1. You can use aplay to get a list of soundcards configured by alsa
   • {{{ $ aplay --list-devices

aplay: device_list:200: no soundcards found... }}}

1. The following commands can help to figure out what sound card (chip set) you have (Look for lines that contain 'Multimedia audio controller'). The actual {sub,}{vendor,device} IDs are important. That's how we track whether something exists as a quirk or needs to be added/modified.
   • {{{ $ lspci -vvnn

$ lspnp -v }}}

1. The following command lists the codecs involved. The output from this command is vital. Different codecs pushing the same driver (say, intel8x0, emu10k1, or hda-intel) exhibit a huge variation in errata.

   • {{{ tail -2 /proc/asound/oss/sndstat

}}}

1. It is imperative that you include the amixer output from your preferred (the one that's giving problems) audio device. The community has spent years documenting known mixer issues on http://alsa.opensrc.org/ (see drivers). For instance, many of the codecs driving cs46xx, emu10k1, and intel8x0 require multiple elements to be selected, unmuted, and raised to audible levels.

   • {{{ amixer

}}}

1. This script command (which is really just filtered cat /proc/asound/cards) lists the enumerated sound devices on your system.
   • {{{ asoundconf list

}}}

1. We need to know if you've modified any runtime configuration files that affect how alsa-lib interacts with your sound devices. The nonexistence of the above files is not a problem.
   • {{{ cat /etc/asound.conf ~/.asoundrc*

}}}

1. Many codecs and drivers, upon initialization, will spit something via printk() into the kernel ring buffer. Any diagnostic messages will appear in this output.
   • {{{ dmesg

}}}

1. Sound devices require resources. We need to see if those resources are properly assigned, the above command lists interrupts used.
   • {{{ cat /proc/interrupts

}}}

Misc

A bit of useful information regarding manual installation of sound drivers as well as troubleshooting pulseaudio, flash, and sound mixing can be found here:

https://help.ubuntu.com/community/DebuggingSoundProblemsMisc

Links

http://alsa.opensrc.org/index.php

CategoryDocumentation CategoryBugSquad