Precision 7770 / Built-in Microphone not working / Linux

I posted about this in the Linux General forum and didn't get any replies so now I'm trying here.

I have a fairly new (built March 2023) Precision 7770 with a fully-patched OpenSUSE 15.5 installed.

On the whole, it is working fine - except for the microphone (but the speakers work) - I would appreciate assistance troubleshooting this.

As I noted in the original posting, I've been through the OS troubleshooting guides without success.

I'm still on the 1.9 BIOS, and I do plan to upgrade, but none of the changelogs for the versions since then seem to have an applicable fix. I did see the 1.18.0 BIOS debacle, so I plan to upgrade to v1.16.

From what I can tell, the proper Linux driver is loading. The speakers work, and I gather the same chip drives both the speakers and the microphone.

This only affects the built-in microphone. I can add a headset (for example, Zone) and that works fine (both speakers and microphone). ALSA (the Linux sound system) simply does not "see" the built-in microphone at all. The built-in microphone is enabled in BIOS. The camera works fine. The ALSA-info output is in my original posting; aside from keeping the OS updated, the only other change since then is that I installed the intel-media-driver package.