Answer by Tejas Ghalsasi for Sound Input device (microphone) not working

try this in terminal for no sound:

sudo alsa force-reload

restart device and check if sound is workin?

if it doesnt do this:

sudo apt-get remove --purge alsa-base pulseaudiosudo apt-get install alsa-base pulseaudio

The following commands will also remove some important dependencies that may break Ubuntu. Type in the command sudo apt-get install ubuntu-desktop to reinstall the removed files.

Restart device and check ..This should probably do the job!