I had a problem with my HDMI without sound and I found this fix.
Edit /etc/default/grub and change this line:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
to this line
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash radeon.audio=1"
Now run "sudo update-grub", then reboot your computer.
Now, the boot stuck in a file systems check. Each time it's stucked in a different message. Sometimes, about bluetooth, others for network monitor etc. I cannot open Linux from recovery and from older versions, each one stuck in a black screen.
I cannot access my pc and if I will not find a sollution soon, I will turn to a clean install with losing all my data :(