I'm a dedicated long term Ubuntu Mate 18.04 user with no inclinations at all to 'upgrade'.
2 things have happened (coincidentally ??) before this failure:
1 - There was a kernel update just before shutting it down;
2 - My PC was then shut down & disconnected for ~1 week.
Upon reconnection - it had become mute.
I did some searching, found some suggestions to fix it via Alsa and PulseAudio manipulations - but nothing I found worked to fix this.
Finally I gave in & connected my display via HDMI & now have very tinny sound via its internal speakers.
I prefer to use line out as I have very good external speakers & I can also easily switch to my headphones.
Never in the past have I needed or used spdif/HDMI so could do without those options altogether, but found no way to remove or disable the spdif.
When you say mute, do you mean that the line out 'device' appears in the Output panel of Sound Preferences (the mate-volume-control application), but when you select it, you cannot hear any sound?
default
Playback/recording through the PulseAudio sound server
null
Discard all samples (playback) or generate zero samples (capture)
pulse
PulseAudio Sound Server
sysdefault:CARD=SB
HDA ATI SB, ALC892 Analog
Default Audio Device
front:CARD=SB,DEV=0
HDA ATI SB, ALC892 Analog
Front speakers
surround21:CARD=SB,DEV=0
HDA ATI SB, ALC892 Analog
2.1 Surround output to Front and Subwoofer speakers
surround40:CARD=SB,DEV=0
HDA ATI SB, ALC892 Analog
4.0 Surround output to Front and Rear speakers
surround41:CARD=SB,DEV=0
HDA ATI SB, ALC892 Analog
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=SB,DEV=0
HDA ATI SB, ALC892 Analog
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=SB,DEV=0
HDA ATI SB, ALC892 Analog
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=SB,DEV=0
HDA ATI SB, ALC892 Analog
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=SB,DEV=0
HDA ATI SB, ALC892 Digital
IEC958 (S/PDIF) Digital Audio Output
dmix:CARD=SB,DEV=0
HDA ATI SB, ALC892 Analog
Direct sample mixing device
dmix:CARD=SB,DEV=1
HDA ATI SB, ALC892 Digital
Direct sample mixing device
dsnoop:CARD=SB,DEV=0
HDA ATI SB, ALC892 Analog
Direct sample snooping device
dsnoop:CARD=SB,DEV=1
HDA ATI SB, ALC892 Digital
Direct sample snooping device
hw:CARD=SB,DEV=0
HDA ATI SB, ALC892 Analog
Direct hardware device without any conversions
hw:CARD=SB,DEV=1
HDA ATI SB, ALC892 Digital
Direct hardware device without any conversions
plughw:CARD=SB,DEV=0
HDA ATI SB, ALC892 Analog
Hardware device with all software conversions
plughw:CARD=SB,DEV=1
HDA ATI SB, ALC892 Digital
Hardware device with all software conversions
hdmi:CARD=NVidia,DEV=0
HDA NVidia, HDMI 0
HDMI Audio Output
hdmi:CARD=NVidia,DEV=1
HDA NVidia, HDMI 0
HDMI Audio Output
hdmi:CARD=NVidia,DEV=2
HDA NVidia, HDMI 0
HDMI Audio Output
hdmi:CARD=NVidia,DEV=3
HDA NVidia, HDMI 0
HDMI Audio Output
dmix:CARD=NVidia,DEV=3
HDA NVidia, HDMI 0
Direct sample mixing device
dmix:CARD=NVidia,DEV=7
HDA NVidia, HDMI 0
Direct sample mixing device
dmix:CARD=NVidia,DEV=8
HDA NVidia, HDMI 0
Direct sample mixing device
dmix:CARD=NVidia,DEV=9
HDA NVidia, HDMI 0
Direct sample mixing device
dsnoop:CARD=NVidia,DEV=3
HDA NVidia, HDMI 0
Direct sample snooping device
dsnoop:CARD=NVidia,DEV=7
HDA NVidia, HDMI 0
Direct sample snooping device
dsnoop:CARD=NVidia,DEV=8
HDA NVidia, HDMI 0
Direct sample snooping device
dsnoop:CARD=NVidia,DEV=9
HDA NVidia, HDMI 0
Direct sample snooping device
hw:CARD=NVidia,DEV=3
HDA NVidia, HDMI 0
Direct hardware device without any conversions
hw:CARD=NVidia,DEV=7
HDA NVidia, HDMI 0
Direct hardware device without any conversions
hw:CARD=NVidia,DEV=8
HDA NVidia, HDMI 0
Direct hardware device without any conversions
hw:CARD=NVidia,DEV=9
HDA NVidia, HDMI 0
Direct hardware device without any conversions
plughw:CARD=NVidia,DEV=3
HDA NVidia, HDMI 0
Hardware device with all software conversions
plughw:CARD=NVidia,DEV=7
HDA NVidia, HDMI 0
Hardware device with all software conversions
plughw:CARD=NVidia,DEV=8
HDA NVidia, HDMI 0
Hardware device with all software conversions
plughw:CARD=NVidia,DEV=9
HDA NVidia, HDMI 0
Hardware device with all software conversions
user@ubu18046:~/Desktop$
Does that reveal anything which may help to fix this ??
If the problem is somewhere within ALSA, then the following (or similar command) won't produce sound - and may report an error that can help diagnose the problem:
Given that they both worked, that's actually not a lot to go on.
With the speakers plugged in to the line-out (presumably a TRS jack)
Check that nothing is muted (or set to volume zero) in pulsemixer and that the device has a reasonable profile (e.g. Analog Stereo Output).
If using PulseMixer 1.5.1 (what I have): Press F1 to bring up the outputs in pulsemixer and if something is greyed out (that shouldn't be), navigate via arrow keys, then press M to mute/unmute.
This is what I see with headphones plugged in to my laptop:
(side note: I'm thoroughly enjoying Alice Madness Returns, ignore the UMC202HD device, and the Renoir controller)
Check that the device (card) itself has the correct profile, e.g. press F3, navigate to the device, and confirm that it has either Analog Stereo Output (or Analog Stereo Duplex as is the case for me using a headsets with a microphone):
Note: With headphones plugged in the inbuilt speaker is muted while the headphones are at full volume. This is what happens on my machine when ALSA is (correctly) selecting the TRS jack from the device for output when it is plugged in. The opposite will be true when the headphones are unplugged, then the speaker will be at full volume, and headphones will be muted.
Wow - sincerest thanks for your time & efforts to help me out.
.
I did check all that you suggested & nothing seems amiss - but of course I may be missing something important.
. BUT=>
Strangely enough when I opened sound settings via the tray icon suddenly both line out & headphones connectors have begun working again for no apparent cause or reason that I'm aware of.
.
So for this minute all seems to be well & working correctly again.
. Electronic gremlins perhaps ?!?
Could be a hardware gremlin. Otherwise, sometimes PulseAudio (or underneath that, ALSA) have hiccups. You can restart the former with pulseaudio --kill, and the latter with alsactl restore. If that doesn't work, come back here I guess!
Thanks Again Steven_Wade !!
It was like it had gone insane & stayed that was across several reboots...
And then it just came back.
Still working today too.
Definitely crazy-making & this highlights how accustomed I've become to having the PC as my sole media source.
Which is most of the time.
After the last updates all system sounds through PA burp or croack, and only when repeatedly played over and over they begin to sound as expected, but then the UI plays them again after a while and they burp and croack again.