Wrt the following I am making some assumptions:
(a) Dell PC hardware for front mic is functioning correctly
(b) External mic hardware, that you are using, is functioning correctly
(c) you ran those arecord commands in a konsole or xterm and received no error messages - but rather just had no sound.
You can verify (a) and (b) by
(1) check external mic on rear mic outlet on PC to see if it works (be certain to unmute rear mic in amixer and also move up rear mic booster value in amixer before testing).
(2) check external mic on a different PC to see if mic works
I assume you have already verified (c) [no error messages] as you have said nothing in this thread.
Logically - assuming no recording, then I think we have established there is likely a problem wrt alsa and/or the alsa configuration, for that ‘arecord’ command, run in a konsole/xterm, should have worked.
One can try and tune alsa configuration with ‘model’ commands, as I noted in an earlier thread. The options for the ALC269 are:
**ALC**22x/23x/25x/**269**/27x/28x/29x (and vendor-specific ALC3xxx models)
laptop-amic Laptops with analog-mic input
laptop-dmic Laptops with digital-mic input
alc269-dmic Enable ALC269(VA) digital mic workaround
alc271-dmic Enable ALC271X digital mic workaround
inv-dmic Inverted internal mic workaround
headset-mic Indicates a combined headset (headphone+mic) jack
headset-mode More comprehensive headset support for ALC269 & co
headset-mode-no-hp-mic Headset mode support without headphone mic
lenovo-dock Enables docking station I/O for some Lenovos
hp-gpio-led GPIO LED support on HP laptops
dell-headset-multi Headset jack, which can also be used as mic-in
dell-headset-dock Headset jack (without mic-in), and also dock I/O
alc283-dac-wcaps Fixups for Chromebook with ALC283
alc283-sense-combo Combo jack sensing on ALC283
tpt440-dock Pin configs for Lenovo Thinkpad Dock support
and what one can do, is try applying each of those, one at a time, to see if any work. Even if the description does not appear to solve your problem, it could be worth while trying the setting.
To try a model setting (for example “dell-headset-dock” ) , you would change your /etc/modprobe.d/50-sound.conf file (using root permissions) to instead read:
options snd slots=snd-hda-intel model=dell-headset-dock,snd-hda-intel
# u1Nb.KS5lwYSNfTE:7 Series/C216 Chipset Family High Definition Audio Controller
alias snd-card-0 snd-hda-intel
# NXNs.k4J9ONqCLEB:High Definition Audio Controller
alias snd-card-1 snd-hda-intel
Reboot and test. That might even ‘break’ your sound after the reboot. In which case, simply remove that edit entry of “model=dell-headset-dock”, and reboot and all should be back to how it was before.
You can then cycle through each one of those 15 different model configurations one at a time, rebooting for each, testing with the 'arecord … " that I gave previous, to see if any record sound.
Thats a lot of testing.
If you prefer not to do all that, then an easier approach is to write a bug report on openSUSE kernel that recording does not work. A bug report will get the attention of the openSUSE sound packager, who is also an alsa sound driver developer. Possibly the best person (in the world ?? ) for sorting the problem. There is guidance here for writing a bug report : https://en.opensuse.org/openSUSE:Submitting_bug_reports
You can use your openSUSE forum username and password when logging on to Bugzilla. Attach to the bug report the file you get by running:
do not bother to reference this forum thread, as the openSUSE sound packager will not read a forum thread. Every few days check the bug report for a reply. Likely you will be asked some questions and given some instructions to test. After you answer any question in the bug report, clear any “need info” flag that may have been raised in the bug report - as that is the indicator to the openSUSE packager that you have replied.
Good luck in your efforts.