So I have the third party nvidia graphics drivers up to date for my machine, and the HDMI port on my graphics card works fine.
There is a secondary HDMI port on my machine but it is not working. It works fine on windows, and it even turns on briefly while Ubuntu boots, but other than that it does not work on Ubuntu.
xrandr does not detect it, I've entered the system settings gui and tried detect display but nothing happens. I have installed the ubuntu-common drivers package, the nvidia-common drivers package and the latest nvidia graphics drivers. I'm not sure what else I need, but I'm sure it's some driver issue because it works on windows so I know the hardware is fine.