[13.1/KDE] screen stays black after sleep

the laptop (an older dell) was woking fine for months.
after letting yast install updated packages today the screen stays black if the laptop tries to come back from sleep. the harddisk sounds the usual way while the laptop is waking up.
ALT+CTRL1+F1had no effect.
ALT+CTRL+DEL could reboot with a working screen.

tried several times, so the reboot didn’t solve.

any ideas??

Try to uninstall pm-utils, or set SLEEP_MODULE=“kernel” in /usr/lib/pm-utils/defaults.

You might also try to set HIBERNATE_RESUME_POST_VIDEO=“yes” in /usr/lib/pm-utils/defaults (but this only has effect if pm-utils is installed).

didn_t work.

can nvidia drivers be the reason?
they had been part of the update that caused the problem.

Probably.
Many people seem to experience problems with the nvidia driver and resume after suspend.
Nvidia blames the kernel developers, and the kernel developers say it’s nvidia’s fault…:
See this bug report e.g. https://bugzilla.opensuse.org/show_bug.cgi?id=889660
and these forum threads:
https://forums.opensuse.org/showthread.php/494706-openSUSE-13-1-KDE-inconsistant-resume-from-Suspend-to-RAM
https://forum.kde.org/viewtopic.php?f=111&t=121590
(there are others as well)

No idea if your problem is related or if you have a different problem, but I have no idea what else to try either than what I posted already.

Just one more thing: try to disable desktop effects completely. Does resume work then?