Soundcard problem
 

Hi all,

I'm running Ubuntu 8.04, which has been updated to within a week or so ago. Its running on a Jetway j7f2, which has the via CN700 chipset. This is supported by the alsa driver snd_via82xx.

My sounds works for a period of up to a day, and then begins to cut in and out. The sound will briefly go crackly and then disappear altogether. sometimes it will never come back at all, other times it comes and goes for 2 or three seconds at a time.

I can sometimes provoke it to come back for a short while by fiddling with the DXS channel volume in alsamixer.

/etc/init.d/alsa-utils restart also seems to bring it back for a while, but then it will misbehave again.

I ran speaker-test to see if I got a similar problem, which I did, so I exited speaker test after it went silent. About 4 seconds after I had exited the speaker test utility I got about 3 seconds of pink-noise output. I think something is going seriously wrong with buffering somewhere.

dmesg shows nothing
/var/log/messages shows nothing
I can't find a log specifically for alsa anywhere

Can anyone suggest how I can proceed to diagnose this problem?

Thanks all,

Pete

have you considered looking at the speaker wire or the plug? (the weakest link when something that was working start doing just what you describe)...

I've tried two different sets of speakers and they both do the same thing. As mentioned I can also bring the sound back without physically touching the PC. I also thought it might be heat related and temporarily hooked up another big fan to the case, and installed lmsensors to watch the temp, but when it occurs seems to be unrelated to temperature.

what i do to test speaker wires & plugs is i launch an audio player like audacious or xmms (or whatever you have) and play some music, then when you know it is playing shake the speaker wires and wiggle the speaker wires close to the the plug and speakers...

so lsmod shows the audio drivers loaded? i read in another post someone was having an audio driver conflict when they were trying to set up & configure a Logitech webcam, so try to change the configuration from the OSS outout to alsa and back...

Yup,

Lsmod shows all the alsa drivers loaded including the snd_via82xx module for the via hardware. If I kill this module the sound dies, and as I said sound might work for 24hours quite happily.

Interesting you should mention the OSS driver. I've just been reading something about that, but the driver required doesn't appear to come with ubuntu so I'd have to compile em. Its just hassle I don't need.

Cheers

Pete

fire up synaptic and search for alsa then scroll till you see alsa-oss