SUMMARY Since about a week now (after running some system updates) my Notebooks screen will suddenly turn black after something in between 1 min after plasma has completely started (rare) and more often something between 10 min and 30 min. The backlight is still on, I can adjust the brightness. Moving the mouse after some idle time makes the screen turn on (changes from pitch black to backlit black). I can ssh in and run commands. Videos in firefox continue playing and can be paused/started by mouse clicks. I can often press the power button and then enter and it will shutdown. Plymouth will shortly show the Kde neon logo before the computer turns off. Pressing Shift+Alt+F12 does nothing. When I ssh in, kwin_x11 is still running. STEPS TO REPRODUCE 1. Start Notebook 2. Do anything or nothing 3. empty/black screen OBSERVED RESULT EXPECTED RESULT SOFTWARE/OS VERSIONS Linux/KDE Plasma: plasma-workspace 4:5.22.4-0xneon+20.04+focal+release+build42 amd64 Plasma Workspace for KF5 (available in About System) KDE Plasma Version: KDE Frameworks Version: libkf5windowsystem-dev 5.85.0-0xneon+20.04+focal+release+build22 Qt Version: libqt5core5a:amd64 5.15.2+p20.04+tunstable+git20210826.0127-0 ADDITIONAL INFORMATION replacing kwin via ssh: DISPLAY=:0 kwin_x11 --replace kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5127:46: this compose sequence is a duplicate of another; skipping line kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5129:48: this compose sequence is a duplicate of another; skipping line kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5131:48: this compose sequence is a duplicate of another; skipping line kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5135:47: this compose sequence is a duplicate of another; skipping line kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5137:46: this compose sequence is a duplicate of another; skipping line kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5145:48: this compose sequence is a duplicate of another; skipping line kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5149:46: this compose sequence is a duplicate of another; skipping line kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5151:46: this compose sequence is a duplicate of another; skipping line kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5155:45: this compose sequence is a duplicate of another; skipping line kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5158:46: this compose sequence is a duplicate of another; skipping line kwin_xkbcommon: XKB: inet:224:50: unrecognized keysym "XF86FullScreen" qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 6184, resource id: 29360235, major code: 18 (ChangeProperty), minor code: 0 OpenGL vendor string: Intel OpenGL renderer string: Mesa Intel(R) HD Graphics 620 (KBL GT2) OpenGL version string: 4.6 (Compatibility Profile) Mesa 21.0.3 OpenGL shading language version string: 4.60 Driver: Intel GPU class: Kaby Lake OpenGL version: 4.6 GLSL version: 4.60 Mesa version: 21.0.3 X server version: 1.20.11 Linux kernel version: 5.11 Requires strict binding: yes GLSL shaders: yes Texture NPOT support: yes Virtual Machine: no kwin_core: XCB error: 10 (BadAccess), sequence: 6327, resource id: 1956, major code: 142 (Composite), minor code: 2 (RedirectSubwindows) but nothing happens in journalctl I can see some of these when the screen first goes blank: Sep 04 22:26:15 sisBook kwin_x11[1182]: kwin_core: XCB error: 3 (BadWindow), sequence: 4545, resource id: 14710390, major code: 129 (SHAPE), minor code: 8 (GetRectangles) Sep 04 22:26:18 sisBook plasmashell[1264]: trying to show an empty dialog Sep 04 22:26:19 sisBook kwin_x11[1182]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 14198, resource id: 41943045, major code: 18 (ChangeProperty), minor code: 0 Sep 04 22:26:19 sisBook systemd[1013]: Started Discover - Programmverwaltung. Sep 04 22:26:19 sisBook kwin_x11[1182]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 14203, resource id: 41943046, major code: 18 (ChangeProperty), minor code: 0 kwin support info (after black and replacing via ssh): https://invent.kde.org/-/snippets/1835 nothing appears in dmesg
I attached an external monitor, opened the screen settings, toggled the laptop screen off and on and it was completely normal again. Let's see for how long. But this makes me doubt it is an hardware issue (besides that it started with the last update)
Is the cursor visible?
No mouse cursor (or anything for that matter) is visible on the build in screen. Mouse works just fine on external display I checked /sys/class/backlight/intel_backlight/actual_brightness but it doesn't change when the content disappears (and the screen is not pitch black)
It seems to be a mechanical defect, sorry for the noise