no sound whatsoever

After my recent reinstallation all but some video quirks seemed to work fine. Then today I discovered I had no sound whatsoever. Right after my reinstallation I discovered using alsamixer that Master was muted. Settings were not changed in the meantime, but today I discovered it had been muted again by itself. So I unmuted it, but I still have no sound, tested by playing all sorts of video and audio files. Also checked physical connections of course. I’m at a loss here, so I’ll post my logs here:

kodi@kodi:~$ dpkg -l |grep mesa | pastebinit
http://paste.ubuntu.com/23572014/
kodi@kodi:~$ DISPLAY=:0 vainfo | pastebinit
libva info: VA-API version 0.39.2
libva info: va_getDriverName() returns 0
libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/i965_drv_video.so
libva info: Found init function __vaDriverInit_0_38
libva info: va_openDriver() returns 0
http://paste.ubuntu.com/23572016/
kodi@kodi:~$ cat ~/.kodi/temp/kodi.log | pastebinit
http://paste.ubuntu.com/23572018/
kodi@kodi:~$ dmesg | pastebinit
http://paste.ubuntu.com/23572019/
kodi@kodi:~$ id | pastebinit
http://paste.ubuntu.com/23572022/
kodi@kodi:~$ amixer | pastebinit
http://paste.ubuntu.com/23572023/

Thanks for any insight; especially when I can prevent the installation from sabotaging itself in the future.