Persistent Dummy Output
I don't know what's the problem or why it happens, but that worked for me.
pulseaudio --kill
pulseaudio --start
First, replace any previous configurations:
sudo apt-get update
mkdir PULSE
cd PULSE
apt-get download pulseaudio
ar xvf *
tar xvf dat*
sudo rm /etc/pulse/*
sudo mv etc/pulse/* /etc/pulse/
Then, run the following commands:
sudo apt-get install --reinstall linux-image-$(uname -r)
sudo modprobe snd-hda-intel
rm -r ~/.config/pulse*
pulseaudio -k
source
There doesn't seem to be a solution to this so I just re-installed Kubuntu and the sound works perfect.
Downside: wiped everything else (but I didn't have much on my ssd so it was fine)