Once upon a time, Chris Adams <linux(a)cmadams.net> said:
I installed Fedora 25 with the MATE desktop on my Thinkpad Carbon X1
(4th gen). When I lock the desktop or the screensaver kicks in, the
display doesn't actually blank.
On more searching, this is a known bug with MATE and the blank
screensaver:
https://bugzilla.redhat.com/show_bug.cgi?id=1397900
https://github.com/mate-desktop/mate-screensaver/issues/103
--
Chris Adams <linux(a)cmadams.net>