[alsa-devel] Microphone detected, but no output for all ASUS G751xx with ALC668 chipset

[Takashi Iwai]

On Thu, 06 Sep 2018 20:44:30 +0200,
Håvard wrote:
> 
> Additional relevant info:
> 
> A similar issue was also discussed three years ago on Sun Jun 17:15:54 CEST
> 2015 and was about his surround sound setup, but did not touch on the
> external microphone problem:
> http://mailman.alsa-project.org/pipermail/alsa-devel/2015-June/093317.html
> 
> alsa-info.sh:
> http://www.alsa-project.org/db/?f=1d8616ba5977308e03db6c3a86e36e9e9b38d6f0
> 
> Graph of ALC668 chipset from hdaanalyzer:
> http://i.imgur.com/c08DNJW.png
> 
> setting alsa-mode[1-8] does nothing to help the issue.
> 
> There are several of similar bug reports around the web experiencing
> similar issues, and on different distros.
> 
> Microphone works perfectly in windows
> 
> I have a ASUS ROG G751JT, but this problem seems to happen with all laptops
> under the G751 name.

When you enable the loopback volume and switch, and unmute/adjust "Mic
Playback Volume", and "Mic Playback Switch", do you hear the input
from the ext mic?  It's a route directly from NID 0x18 to the mixer
NID 0x0b, then output mixer NID 0x0c, then outputs.  So this can be
used to verify the hardware routing.

If you don't hear via this route, it means that the input from the ext
mic pin itself is broken, and it implies that something outside
HD-audio codec.


Takashi