First of all, sorry for my late reply: It took me a while before I
realized this is a mailing list. (I also hope Evolution is smart enough
to figure out to send the right In-Reply-To header.)
On Sat, 23 Sep 2017 20:28:59 -0500, David Wright wrote:
Does the screen turn blank after a random time, or at the time of
an event (like starting X, or starting an application, or some
heavy processing etc). After a minute or half an hour?
I want to clarify it happens at random times, not at a certain interval
after boot or during any event. I now also realize that I have been
unclear that it's actually happening temporarily: after a random number
of seconds, the screen shows the display again. I haven't found any
pattern causing the screen to show nothing, nor any pattern making the
desktop (and the running applications) show again. Sometimes this on-
off switch happens multiple times during the day. Usually the screen
goes only blank for a couple of seconds (1‒5 seconds), but I also once
had that I had to wait for about 45 seconds before it came back up.
Is the screen really black or just very dark?
Like the screen outputs pure black. I can still adjust the brightness
and this shows a ‘brighter’ or ‘less brighter’ black. It seems no bug
in the brightness settings as in the dual monitor setup I see that the
brightness remained the same after the laptop's screen goes dark.
What happens if you select a VC, or exit X? … … …
Good suggestion to try the virtual console! I've only been able to try
this once: The screen went blank, I switched to tty3 and the screen
showed the tty, I returned to tty2 (running GDM) and everything was
showing there as well. So either the screen was blank for just a second
or so, or switching to a different tty makes the screen come back
again.
I will keep you posted once I've been able to try this more often.
Thanks for everybody's help so far!