I've run into the problem that pavucontrol was not showing me
the internal microphone in Input Devices tab. To no avail.
There was a heureka point: after a tweak of "Internal Mic Boost" in
alsamixer, I was able to record myself and let it reproduce for
confirmation just fine (arecord, aplay).
Then, there was another, when I figured out that in Configuration
tab in pavucontrol, I had "Analog Stereo Output" selected.
When flipped to "Analog Stereo Duplex", everything under Input
Devices started as expected.
This may perhaps be a question on pavucontrol rather than here,
but is it possible that something had changed "Analog Stereo Duplex"
to "Analog Stereo Output" and that something wasn't me? I mean,
information lost on upgrade of pulseaudio or something like this?
If unlikely, still, there would be this RFE from my side on
pavucontrol (let's move this bug over there, then):
Please, when Input Devices tab is empty AND there is not a duplex
mode selected in Configuration tab, show a hint on the former
that the users can help themselves going to the latter and selecting
a duplex option should they expect a microphone settings available.
$ rpm -q pavucontrol alsa-utils; uname -r
snippet from alsa-info.sh:
> !!Soundcards recognised by ALSA
> 0 [PCH ]: HDA-Intel - HDA Intel PCH
> HDA Intel PCH at 0xf2240000 irq 134
> !!PCI Soundcards installed in the system
> 00:1f.3 Audio device : Intel Corporation 100 Series/C230 Series Chipset Family HD Audio Controller [8086:a170] (rev 31)
> Subsystem: Lenovo Device [17aa:5050]
This bug appears to have been reported against 'rawhide' during the Fedora 33 development cycle.
Changing version to 33.
Recently I've seen lots of problems with the pulseaudio profiles getting messed up on their own, exactly like you described, so the end result is microphone not available.. and sometimes one needs to restart pulseaudio and/or re-plug the audio device (usb-headset in my case) before the correct "duplex" profile can be chosen again.
I'm on Fedora 32 atm (but f32 has similar pulseaudio version than F33).