Code Notelets

I recently upgraded from Debian Stretch to Debian Buster (or Debian 9 to Debian 10). I hadn't done anything unusual with my system, so I was expecting a smooth upgrade process. It did work smoothly, with one exception: my monitor simply would not wake up after a screen timeout.   The problem The monitor just refused to wake up after time out, even if I unplugged and replugged its power cord (its own one, separate to the computer). The monitor reported no signal from the computer. However, the computer was actually working fine during this time - the light was on, and the keyboard caps lock key light toggled on and off; a sign that it was indeed working. But with no way to see any of the screen, I simply couldn't do anything to restart the machine except for a hard restart (turning off the computer with the power button and turning it back on). Needless to say, this was not good since I had open unsaved files on my desktop! I couldn't find anything actually helpful o...