In-application sound broke after HDMI connection

[Herkio]

Yesterday I watched a film over HDMI to my tv and selected the tv to be the sound device in sound settings.
Today I rebooted my computer and found that some applications have sound, other don't. The welcome sound disappeared on reboot, as well as sound in firefox (e.g. youtube). Sound in media player works great, as well as the sound of changing the volume. Force-reloading alsa doesn't work, though modules seem to be loaded normally. Any help is appreciated!

Some system info:

4.19.7-041907-generic x86_64 bits: 64 gcc: 8.2.0
Desktop: Cinnamon 3.8.9 (Gtk 3.22.30-1ubuntu1) dm: lightdm Distro: Linux Mint 19 Tara
Machine: Device: laptop System: HP product: HP Pavilion Laptop 15-cw0xxx serial: N/A
Mobo: HP model: 84E7 v: 99.19 serial

Card-1 Advanced Micro Devices [AMD] Device 15e3
driver: snd_hda_intel bus-ID: 04:00.6 chip-ID: 1022:15e3
Card-2 Advanced Micro Devices [AMD/ATI] Device 15de
driver: snd_hda_intel bus-ID: 04:00.1 chip-ID: 1002:15de
Sound: Advanced Linux Sound Architecture v: k4.19.7-041907-generic

lsmod | grep snd

snd_hda_codec_realtek 106496 1
snd_hda_codec_generic 73728 1 snd_hda_codec_realtek
snd_hda_codec_hdmi 49152 1
snd_hda_intel 40960 5
snd_hda_codec 126976 4 snd_hda_codec_generic,snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec_realtek
snd_hda_core 81920 5 snd_hda_codec_generic,snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec,snd_hda_codec_realtek
snd_hwdep 20480 1 snd_hda_codec
snd_pcm 102400 4 snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec,snd_hda_core
snd_seq_dummy 16384 0
snd_seq_oss 36864 0
snd_seq_midi 16384 0
snd_seq_midi_event 16384 2 snd_seq_midi,snd_seq_oss
snd_rawmidi 32768 1 snd_seq_midi
snd_seq 65536 6 snd_seq_midi,snd_seq_oss,snd_seq_midi_event,snd_seq_dummy
snd_seq_device 16384 4 snd_seq,snd_seq_midi,snd_seq_oss,snd_rawmidi
snd_timer 32768 2 snd_seq,snd_pcm
snd 81920 22 snd_hda_codec_generic,snd_seq,snd_seq_device,snd_hda_codec_hdmi,snd_hwdep,snd_seq_oss,snd_hda_intel,snd_hda_codec,snd_hda_codec_realtek,snd_timer,snd_pcm,snd_rawmidi
soundcore 16384 1 snd

[Herkio]

Switching kernels doesn't help, for instance to the mint-distributed 4.15.x.

[MrEen]

Hi Herkio, and welcome to the forum.

Delete the files in ~/.config/pulse then run pulseaudio -k in the terminal. You'll probably need to restart most apps that aren't working, especially Firefox.

Hope that helps.

[Herkio]

It worked a charm, thanks! But I'm curious, what exactly does that do and why did it need to be done? Thanks

[MrEen]

Those are the user pulseaudio config files, and sometimes they get messed up. When you delete them, they get regenerated with a fresh set. pulseaudio -k kills the running sound daemon, that then restarts itself and will use the new config files.