[CentOS] netbook screen suddenly goes black

Hi all!

I'm running an up to date Centos-7 on my Acer Aspire One netbook. have
been for, well, ever since C7 was released.

Just had an event today that also happened 2 or 3 times with earlier
systems installed, but I never pursued it.

What happens is that suddenly while working away on the desktop the
display suddenly goes black... not black as in turned off, I can see
that the backlight is still on, but no image is displayed. 

Nothing I can do fixes it except a reboot. I've tried CTRL-ALT-BKSP,
CTRL-ALT-DEL, alt+printscreen+r+e+i+s+u+b. none of them do anything
noticeable.

I've been looking at system logs and don't find anything that gives
me a clue what is going wrong when that happens.

neither dmesg, /var/log/Xorg*, nor /var/log/messages contins much. I've
tried digging thru "man journalctl" and ultimately reading thru the
output of journalctl with no arguments.

Can anyone of you provide further hints on what I should be looking
for or at?

thanks!

Fred

-- 
---- Fred Smith -- fredex at fcshome.stoneham.ma.us -----------------------------
               But God demonstrates his own love for us in this: 
                         While we were still sinners, 
                              Christ died for us.
------------------------------- Romans 5:8 (niv) ------------------------------