Problem : After Bluetooth speakers were abruptly switched off, Ubuntu 16.04 on Alienware (17 R2) stopped producing sounds on its analog sound card.
Reason : Doubt an inviable configuration was left behind for the sound card.
- Open terminal
- Run –
killall pulseaudio; rm -r ~/.config/pulse/* ; rm -r ~/.pulse*
- Wait for 10 seconds.
- Reboot the machine. (Fully power off and then boot)
- This should fix the problem, else look into the reference link below.
Reference : https://help.ubuntu.com/community/SoundTroubleshootingProcedure