Lost sound to monitor 20.04

For some reason I no longer have any sound to my monitor plugged in by the 3.5mm Jack from the Speaker output. Plugging my monitor into phone sound comes through the monitors speakers so that rules out the monitor and the cable being the issue, the only noise I hear is a pop sound from the monitor.

The soundcard is... a 00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 02) Subsystem: Hewlett-Packard Company 82801I (ICH9 Family) HD Audio Controller

The result of $ sudo dmesg | grep -i audio

    pacmd list cards |egrep -i "output|active" Defaultsink name: alsa_output.pci-0000_00_1b.0.analog-stereo
Default source name: alsa_output.pci-0000_00_1b.0.analog-stereo.monitor
    name: <alsa_output.pci-0000_00_1b.0.analog-stereo>
        analog-output-lineout: Line Out (priority 9000, latency offset 0 usec, available: no)
        analog-output-speaker: Speakers (priority 10000, latency offset 0 usec, available: unknown)
        analog-output-headphones: Headphones (priority 9900, latency offset 0 usec, available: no)
    active port: <analog-output-speaker>
    name: <alsa_output.pci-0000_00_1b.0.analog-stereo.monitor>
        output:analog-stereo: Analogue Stereo Output (priority 39268, available: unknown)
        output:analog-stereo+input:analog-stereo: Analogue Stereo Duplex (priority 6565, available: unknown)
    active profile: <output:analog-stereo>
        alsa_output.pci-0000_00_1b.0.analog-stereo/#1: Built-in Audio Analogue Stereo
        alsa_output.pci-0000_00_1b.0.analog-stereo.monitor/#1: Monitor of Built-in Audio Analogue Stereo
        analog-output-lineout: Line Out (priority 9000, latency offset 0 usec, available: no)
        analog-output-speaker: Speakers (priority 10000, latency offset 0 usec, available: unknown)
        analog-output-headphones: Headphones (priority 9900, latency offset 0 usec, available: no)
    sink: 1 <alsa_output.pci-0000_00_1b.0.analog-stereo>
1 source output(s) available.
    source: 1 <alsa_output.pci-0000_00_1b.0.analog-stereo.monitor>
        module-stream-restore.id = "source-output-by-application-id:org.gnome.VolumeControl"

If anything there helps. I can see looking at sound settings that the sound bar is moving up and down. sound settings

What it looks like using Alsamixer

Alsamixer

Sound was previously working.

I regularly lose sound to my 3.5mm (jack) speakers. When I open settings and test the output, I hear nothing. Changing output to headset and changing it back also doesn't help.

Strangely, changing audio output from a GNOME-extension solves my problem. Maybe you should give it a try. https://extensions.gnome.org/extension/906/sound-output-device-chooser/

You could also run alsamixer on terminal, press F6 and check if your output is listed.