Started having issues on Ubuntu with the HDMI output. I hit the power button with my foot and caused the computer to restart. After, the screen was blank, save for its default message indicating to 'Check the video cable' I had tried switching the display, restarting, a different HDMI cabel, etc. I have a Gigabyte motherboard, an intel CPU, an AMD graphics card is installed, but has been broken for quite some while.