[X751BP, Conexant CX20751/2, Mic, Internal] No sound from insternal microphone

[Benjamin Drung]

There is no sound from the internal microphone. Recordings show total silence. The workaround is to use an external microphone and connect it to the external audio jack. alsamixer does not show any option to switch between the external audio jack and the internal microphone.

We also tested the latest linux kernel from lunar (version 6.2.0-19.19), but this newer Linux kernel behaved the same.

Laptop: Asus K751B
ProblemType: Bug
DistroRelease: Linux Mint 21
Package: alsa-base 1.0.25+dfsg-0ubuntu7 [origin: Ubuntu]
ProcVersionSignature: Ubuntu 5.15.0-69.76-generic 5.15.87
Uname: Linux 5.15.0-69-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu82.3
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: klingenberg 1069 F.... pulseaudio
 /dev/snd/controlC0: klingenberg 1069 F.... pulseaudio
CasperMD5json: {
CurrentDesktop: X-Cinnamon
Date: Sat Apr 8 17:15:03 2023
InstallationDate: Installed on 2022-09-13 (206 days ago)
InstallationMedia: Linux Mint 21 "Vanessa" - Release amd64 20220726
PackageArchitecture: all
SourcePackage: alsa-driver
Symptom: audio
Symptom_AlsaRecordingTest: ALSA recording test through plughw:Generic failed
Symptom_Card: Eingebautes Tongerät - HD-Audio Generic
Symptom_DevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: klingenberg 1069 F.... pulseaudio
 /dev/snd/controlC0: klingenberg 1069 F.... pulseaudio
Symptom_Jack: Mic, Internal
Symptom_Type: No sound at all
Title: [X751BP, Conexant CX20751/2, Mic, Internal] No sound at all
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/03/2018
dmi.bios.release: 5.12
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: X751BP.312
dmi.board.asset.tag: ATN12345678901234567
dmi.board.name: X751BP
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: 1.0
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK COMPUTER INC.
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrX751BP.312:bd04/03/2018:br5.12:svnASUSTeKCOMPUTERINC.:pnX751BP:pvr1.0:rvnASUSTeKCOMPUTERINC.:rnX751BP:rvr1.0:cvnASUSTeKCOMPUTERINC.:ct10:cvr1.0:sku:
dmi.product.family: X
dmi.product.name: X751BP
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK COMPUTER INC.
modified.conffile..etc.apport.crashdb.conf: [modified]
mtime.conffile..etc.apport.crashdb.conf: 2023-04-08T16:22:49.366615

[Benjamin Drung (bdrung)]

Side note:

```
$ cat /var/log/installer/casper-md5check.json
{
```