No sound on Ubuntu/Windows dual-boot
TL;DR: Booting into Ubuntu after first booting into Windows disables sound on Ubuntu (dual-boot Ubuntu 16.04 LTS/Windows 10)
Recently I decided to try Linux, so I installed Ubuntu 16.04 LTS as a dual-boot option to already installed Windows 10 on my laptop. But I found out no sound is coming out of my speakers when using Ubuntu (sound works fine on Windows).
So I've tried this guide, and found out step #1C helped (it installed some updates). I later restarted and switched to Windows. As I later switched back to Ubuntu, no sound was coming out of speakers again so I tried the same as before (step #1C), but now it didn't solve the problem (no updates were installed as the system was up to date).
I later tried modifying alsa-base.conf file as pointed out here, but it also didn't help.
Somewhere on the Internet I read that the issue could be caused by Windows Fast Boot. I tried to cold restart (holding power button for ~5 sec) laptop and log into Ubuntu first, and now the sound worked. So I switched to Windows and disabled Fast Boot in power options. Then I switched back to Ubuntu but the sound was not working again. I tried cold restarting again and switched between Ubuntu and Windows but the issue remains same. Booting into Ubuntu after first booting into Windows disables sound on Ubuntu.
NOTE: Pulseaudio shows speakers are not muted
This problem occurs after booting into a different OS than previously.
Just put the computer to sleep and wake it up, and the problem is solved, the sound comes back. Works both ways round for Windows and Ubuntu
However this problem seems to be fixed in the new ubuntu 18.04
Waking from sleep didn't resolve my issue. But this did:
Log into Windows
Go to Device Drivers
Find Intel Audio Driver
If it has a warning flag next to it, update driver.
Worked immediately after the update completed.