Sound problems on Ubuntu 18.04 LTS

[ian]

Hi folks

I'm having problems getting sound on my Ubuntu 18.04 LTS box.

When I look at the Settings > Sound, I see the dreaded 'Dummy output' and no other output devices.

I've looked at various help pages, of which:
https://askubuntu.com/questions/1180851/sound-card-not-detected-dummy-output-only-on-dell-xps-13-9350
was the last one.

I'll give a few command outputs which will hopefully give someone a clue of how I can proceed.

1. user at pc:~$ pacmd list-cards
0 card(s) available.

2. user at pc:~$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: MID [HDA Intel MID], device 0: ALC888 Analog [ALC888 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
card 0: MID [HDA Intel MID], device 1: ALC888 Digital [ALC888 Digital]
   Subdevices: 1/1
   Subdevice #0: subdevice #0

3. 'alsamixer' shows:
Card: HDA Intel MID
Chip: Realtek ALC888
and all of the volume controls are at 100.

4. speaker-test does not produce any sound.

5. aplay -D sysdefault /usr/share/sounds/alsa/Front_Center.wav

6. user at pc:~$ ps -ef | grep pulse
lightdm   1674     1  0 11:34 ?        00:00:00 /usr/bin/pulseaudio --start --log-target=syslog
u3496     2147     1  0 12:40 ?        00:00:00 /usr/bin/pulseaudio --start --log-target=syslog
u3496     8049  2574  0 13:13 pts/1    00:00:00 grep --color=auto pulse

7. user at pc:~~$ lsmod | grep snd
snd_seq_midi           20480  0
snd_seq_midi_event     16384  1 snd_seq_midi
snd_seq                69632  2 snd_seq_midi,snd_seq_midi_event
snd_rawmidi            36864  1 snd_seq_midi
snd_seq_device         16384  3 snd_seq,snd_seq_midi,snd_rawmidi
snd_hda_codec_realtek   118784  1
snd_hda_codec_generic    81920  1 snd_hda_codec_realtek
ledtrig_audio          16384  2 snd_hda_codec_generic,snd_hda_codec_realtek
snd_hda_intel          49152  4
snd_hda_codec         131072  3 snd_hda_codec_generic,snd_hda_intel,snd_hda_codec_realtek
snd_hda_core           90112  4 snd_hda_codec_generic,snd_hda_intel,snd_hda_codec,snd_hda_codec_realtek
snd_hwdep              20480  1 snd_hda_codec
snd_pcm               102400  3 snd_hda_intel,snd_hda_codec,snd_hda_core
snd_timer              36864  2 snd_seq,snd_pcm
snd                    86016  18 snd_hda_codec_generic,snd_seq,snd_seq_device,snd_hwdep,snd_hda_intel,snd_hda_codec,snd_hda_codec_realtek,snd_timer,snd_pcm,snd_rawmidi
soundcore              16384  1 snd

8. user at pc:~$ pulseaudio -k ; pulseaudio -v
I: [pulseaudio] (alsa-lib)utils.c: could not open configuration file /usr/share/alsa/ucm/HDA Intel MID at 0xfbef4000 irq 28/HDA Intel MID at 0xfbef4000 irq 28.conf
I: [pulseaudio] (alsa-lib)parser.c: error: could not parse configuration for card HDA Intel MID at 0xfbef4000 irq 28
I: [pulseaudio] (alsa-lib)utils.c: could not open configuration file /usr/share/alsa/ucm/HDA Intel MID/HDA Intel MID.conf
I: [pulseaudio] (alsa-lib)parser.c: error: could not parse configuration for card HDA Intel MID
I: [pulseaudio] (alsa-lib)main.c: error: failed to import HDA Intel MID use case configuration -2
I: [pulseaudio] alsa-ucm.c: UCM not available for card HDA Intel MID
I: [pulseaudio] alsa-util.c: Failed to set hardware parameters on plug:hw:0: Invalid argument
I: [pulseaudio] (alsa-lib)control.c: Invalid CTL front:0
I: [pulseaudio] alsa-util.c: Unable to attach to mixer front:0: No such file or directory
I: [pulseaudio] alsa-util.c: Successfully attached to mixer 'hw:0
(I have the whole log file which I can send if it'll help)

I also tried uninstalling and re-installing various audio components, but nothing makes my soundcard show up and I have no sound.

Any ideas gratefully accepted.

Thanks

ian