l have HP dv6 and was having the same problem. l fixed it by terminal / alsamixer.
Open a terminal. (The quickest way is the Ctrl-Alt-T shortcut.)
Enter alsamixer”
and press the Enter key.
You will now see a user interface. In this user interface, you can do the following:
- Select your correct sound card using F6 and select F5 to see recording controls as well
- Move around with left arrow and right arrow keys.
- Increase and decrease volume with up and down arrow keys.
- Mute / Unmute with the M key. An MM means muted, and OO means unmuted.
- Exit from alsamixer with the Esc key.
A caveat here: When you mute or unmute something, pulseaudio might pick it up and mute and unmute other controls, as well as PulseAudio’s main mute.