microphone on acer one D255 doesn't works

well, I tried all the combinations:
from asus-mode1 to asus-mode7, and for each of them:
pavucontrol>[tab]configuration>internal audio>[profile]analog stereo duplex and [profile]analog surround 4.0 output + analog stereo input, and for each af them:
Internal audio analog stereo>[port]internal microphone and [port]analog microphone
[front left and front right]at MAX>[no muted]>[channels locked together]
[front left] at MAX [front right] at MIN>[no muted]>[channels unlocked]
skype=don’t works in any case,
then I disabled pulseaudio in this way:

setup-pulseaudio --disable

removed:
pavucontrol
pulseaudio
alsa-plugin-pulse
pulseaudio-module-bluetooth
pulseaudio-module-jack
pulseaudio-module-lirc
pulseaudio-module-x11
pulseaudio-module-zeroconf
pulseaudio-module-utils

I didn’t this command

cd /usr/lib64 md HIDDEN mv *pulse* HIDDEN 

 ldconfig

first becouse he said that could be not necessary and second becouse I cannot find /usr/lib64, where does it is?

after this skype works perfectly and audio too, thanks a lot for everything:)
ciao Pier