pulseaudio - Sound stopped working on Ubuntu 16.10, Dell vostro 5568 - Ask Ubuntu

i installed ubuntu 16.10 on dell vostro 5568 laptop. working fine (good sound speakers). plugged headphones (koss) in headset connector.

the audio controller on laptop realtek alc3246 waves maxxaudio pro. external interface (connector number 6, in above figure) microphone in/stereo headphones/external speakers connector.

ubuntu showed popup dialog question type of device trying connect. think there 3 options. choose between microphone/headphones/headset. chose headphones. , after that, there sound headphones hours. unplugged headphones. , later tried replug headphones, there no sound headphones @ all. also, when unplugged them there no sound speakers either.

i tried restart machine, did not help. muted.

if open system settings->sound headphones unplugged, screenshot:

when try push test sound button, there no sound either front left, or front right speaker.

edit:

after googling more advice, decided try reinstall alsa-base , pulseaudio

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

however, after rebooting audio icon had disappeared unity system tray, , in addition no longer able open system setting system tray.

so situation worse before since cannot access system settings @ ( including audio settings ).

any advice?

to restart pulseaudio can use following commands in terminal:

 sudo pulseaudio -k; pulseaudio -d; 

this should bring sound back, don't know system tray icon. might come when find out how works. appears bug in ubuntu 16.10, happens me when connecting headphones or other external devices (loudspeakers, amplifiers etc.) please file bug on launchpad!