Ubuntu 18.04 random black screen

[batracomiomacheuta]

Hello everyone,

I have Ubuntu 18.04 installed on an HP Elitebook 820, and it generally goes without hitches. Only, since some time after upgrading (from Xubuntu 16.04), the screen randomly goes black, with the retroillumination still active, and stays like that until I suspend and reactivate it. It generally happens when I do nothing for some time, like ten minutes, but other times it stays on for hours without any input, and sometimes it blanks while I'm doing stuff.

Any idea what's the problem? How to solve it?
Thanks

[batracomiomacheuta]

Anybody?

[batracomiomacheuta]

Bumping because I don't even know how to search for a solution on Google. I've tried with little success.