So, when I suspend my laptop, then wake it up later, my laptop does turn on, I'm able to, for example, turn up and down the volume with audio confirmation using the kepboard, but my screen remains black and doesn't show anything until after I restart my laptop.
It is the buggy nouveau driver again. That's what solved the issue for me.
Edit the file
/etc/default/grub (using Vi editor -- some users have not been able to save after editing in Vi and have had to use the alternate "Ex" editing mode, which substitutes
sudo edit below, then Alt+:w and :x for the save and exit commands).
$ sudoedit /etc/default/grub
nouveau.modeset=0 to the line that says
GRUB_CMDLINE_LINUX then press CtrlO to save the file and CtrlX to leave Editor.
$ sudo update-grub
Sorry if what I'm saying is weird (I'm using the google translator). In my case, I am using an Asus Vivobook S15. After desperately searching, I accidentally gave the solution (in my case) and I wanted to share it. What I did was install the Unity Desktop:
$ sudo apt install ubuntu-unity-desktop
And although it seems absurd, it began to work, almost magically. I hope this information is useful for someone. A greeting!
This seems to work for me (as a temporary solution).
Device: HP 245 G5
OS: Xubuntu 18.04
When your screen is blank, this sequence of actions seems to do the trick:
(wait 5 seconds)
CTRL + ALT + F2 (wait a second)
CTRL + ALT + F3 (wait a second)
CTRL + ALT + F7 (wait a second)
ESC (wait a second)
ENTER (3 times XD)
Close your laptop (wait 5 seconds).
Open back your laptop.
And the terrific blank screen is gone.