Ubuntu Linux Mint Desktop Dark Black Cannot See Solution

I'm not sure what caused this as I've never encountered it before. I believe Ubuntu was probably doing some updates and maybe a package like xrandr got updated and the brightness got set very low or maybe the Nvidia driver.

I was using my computer, left it and came back and thought the monitor was off it was so dark. It also could have been related to a bug or issue with the screensaver/sleep mode when the screen starts to dim before sleeping after X minutes and maybe didn't complete.

In either case you can break into another TTY with Ctrl + Alt + F1, login and do this:

Step 1.) Run xrandr

Find the output device name that is connected. In my case it was "DVI=I-1"

xrandr Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 16384 x 16384 DVI-I-0 disconnected (normal left inverted right x axis y axis) DVI-I-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 531mm x 299mm 1920x1080 60.00*+ 1680x1050 59.95 1600x1200 60.00 1440x900 59.89 1280x1024 75.02 60.02 1280x960 60.00 1152x864 75.00 1024x768 75.03 70.07 60.00 800x600 75.00 72.19 60.32 56.25 640x480 75.00 72.81 59.94 DP-0 disconnected (normal left inverted right x axis y axis) DP-1 disconnected (normal left inverted right x axis y axis) DP-2 disconnected (normal left inverted right x axis y axis) DP-3 disconnected (normal left inverted right x axis y axis)