T420/Win10: external mic stopped working (FIXED)

[nofish]

Until recently I could plug a headset in my T420 and sound would get picked up without problem.
Now this doesn't work anymore. Headset is recognized (see gif), but audio doesn't get through anymore.
I know for sure the headset's mic is (still) working fine (using it on a smartphoe).
I'm currently using the Windows included drivers ('High Definition Audio Device', Task manager shows no problem), but I've also tried installing Lenovo's Conexant Audio driver as I have this seen suggested somewhere, but then a mic input is not even available, only a stereo out.

The only thing I can think of that has been changed is installing Windows updates, before the 09/2022 updates it worked (see screenshot).
Could that be the reason, that a Windows update broke it?
Could try to roll back and check but then again stopping updates forever could not be a real solution either.
Any ideas what it could be?

Thanks.

[RealBlackStuff]

Obviously Micro$haft is to blame for Windows 10 and its ilk's bad behaviour.
Linux comes to mind (or go back to W7).

[bhanusuru597]

T14 Gen 2, Windows 10 20H2 64-bt

We bought a number of these T14 systems (20W1 model). Some of our T14 systems, but oddly not all, have trouble with a couple of models of USB headsets. The headset is detected and works. The microphone is detected and does not work. Device manager, Sounds app, Voice Recorder all believe there is a working microphone but no sound is detected when trying to use the microphone. If you try to interact with the microphone via Voice Recorder it simply says that the mic is not working. In Sounds app, if we try the setup microphone option we get a windows error. There are no proprietary drivers - it looks like the mic (detected in Device Manager) uses Microsoft drivers. Other mics work - we tested the internal and headset jack mics as well as alternate USB models.
https://www.routerlogin.net/
pikashow

[nofish]

I don't know about the T14 models but my original issue with the T420 I got fixed meanwhile.
There seems to be a weird bug with it under Win10:
https://forums.lenovo.com/t5/ThinkPad-T ... -p/1023623

For me happened the same thing as this poster, pressed the MIc mute button once and couldn't unmute again.
How I got it fixed was also quite weird, tried to install WinXP (as installing older OS was mentioned there as fix), but install failed (probably old/scratched install disc),
but that seems to have caused a reset or something, so the mic mute button flash briefly, and now sound comes through again under Win10.
Mic mute button doesn't work at all now, but I can live with that.