Sound troubleshooting

So you want your Linux system to play sound, but it does not? Follow these steps to analyze and solve the problem:

The Methodology

If your cables and volume are okay

• Test if your sound card driver and cables are okay; play a test sound:

speaker-test

If you hear a sound

If you hear a sound, your cables and drivers are okay.

If you do not hear a sound

If you do not hear a sound, see if you get an error message.

If you do not get an error message

If you do not get an error message, it can be a driver issue. To find out, delete all sound devices and re-create them:

tweedleburg:~ # rm /dev/dsp*
tweedleburg:~ # udevtrigger

Check again with dd if=/dev/urandom of=/dev/dsp. If you still do neither get an error message nor sound, it is most probably a driver issue. Get yourself a USB soundcard and proceed.

If you get an error message

If you get an error message like this:

tweedleburg:~ # dd if=/dev/urandom of=/dev/dsp
dd: opening `/dev/dsp': Device or resource busy

You should find out what process blocks your sound card. Do this with the command lsof (list open files):

tweedleburg:~ # lsof | grep dsp              
mplayer   18251       root    4w      CHR              14,35               14320 /dev/dsp2

You see, mplayer is blocking /dev/dsp2, you third soundcard. Now find out what soundcard you are using:

tweedleburg:~ # ll /dev/dsp*
lrwxrwxrwx 1 root root       9 Jun 21 10:38 /dev/dsp -> /dev/dsp2
crw-rw---- 1 root audio 14, 19 Jun 21 10:36 /dev/dsp1
crw-rw---- 1 root audio 14, 35 Jun 21 10:36 /dev/dsp2

/dev/dsp points to /dev/dsp2, so the soundcard you are using is blocked by mplayer. So, kill mplayer if you are sure that is what you want:

killall mplayer

Knoppix

When there is no sound under Knoppix try

/etc/init.d/alsa-utils start