Comment # 33 on bug 905418 from Takashi Iwai

(In reply to Ju Ping Chan from comment #31)
> Instead of filing a new bug, my minor problem may hopefully shed new insight
> into this bug.
> 
> I have two audio jacks plugged into my desktop (running TumbleWeed) at the
> same time. In pavucontrol, I can toggle between Line Out (unplugged) and
> Headphone (plugged in).
> 
> Despite it saying Line Out (unplugged), it is actually plugged in.
> 
> Without touching alsamixer though, this convenient setup wouldn't work. I
> figured out that I had to run alsamixer in the terminal, choose "F6 Select
> sound" card, then toggle "Auto-Mute" to "Disabled".
> 
> The alsamixer problem also arises on the Kubuntu 15.04 system I am running
> as a dual-boot for testing as well. The only difference is pavucontrol there
> displays the Line Out and Headphones as correctly plugged in and also
> remembers which choice was last selected after restarting.
> 
> Is this enough information to re-open the bug, or is it better suited as a
> new report?

Another hardware, another issue.  Try pulseaudio packages in OBS
multimedia:libs repo.  If it still doesn't work, please open another bug report
and attach your alsa-info.sh output while line-out isn't plugged.