Hello,
I have this very annoying problem:
Laptop i3 4 GB RAM Lenovo, about 2 years old.
Under Windows 7 sound works well.
Under GNU/Linux sound stops working randomly, after 30 seconds or after 1 hour. The microphone continues to run, but I cannot hear sounds anymore.
I tried installing fresh openSuse 13.2, 41.2 Leap, Tumbleweed, with Xfce and KDE, Xubuntu, Linux Mint Cinnamon, with/without updates. The same behavior.
Until 10 days ago it worked correctly.
I am getting desperate. I searched the internet and tried all possible workouts from the forums.
Later edit: I installed Windows 10. It says the sound card is Conexant CX20671 SmartAudio HD. It worked in Edge, but after I installed Firefox sound do not work anymore, and Edge cannot play video at all (it says an error occured).
Edit: I solved on Windows as explained in this topic: http://answers.microsoft.com/en-us/windows/forum/windows_10-win_upgrade/windows-10-no-sound-with-conexant-high-definition/c5003a01-fa28-4fb1-8676-d70a7b5ff255?page=2 by DewSun.
I updated my post above.
Maybe useful to see the output of dmesg.
Attached.
Also, I tried "speaker-test" - it does not write errors, seems to work, just sound is not audible.
Hm. I don't see any relevant in dmesg.
Just a stupid question: what about volume levels?
What sound system do you use (pulseaudio, I think)?
Sound levels are OK, because I can hear in the beginning. I use alsamixer separately, then pulseaudio.
I attach the sudo alsa-info.sh from my computer, when sound is not working (after it worked for about 1 hour).
http://www.alsa-project.org/db/?f=56cd0ed15e4400040d131a16102a2d7fa6f1fc3c
Update: when the sound works, if I plug in the headphones, sound is audible in the headphones. Also, after the sound stops working in the internal speakers, the headphones still work if I plug them in.
Hm, I don't have any idea :(