To make thing even weirder, one time the external monitor went to sleep while the system was waiting for cryptfs passphrase input and the situation occured already in login screen: Could move the mouse into the black screen with login window following there, and back. I tried to restart lightdm. Still the same. I logged in, restarted lightdm: tada. Monitor back awake showing my desktop. I already tried a different cable but no success. All my other machines are working well with that monitor hosting the same setup (ubuntu/i3).
-- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1915382 Title: external Monitor shows »No Signal« after dpms sleep Status in xorg-server package in Ubuntu: Incomplete Bug description: My external Monitor connected via HDMI is behaving strange and my educated guess is it is related to dpms. Plugging in the monitor it will show »No Signal« although recognized by `xrandr`. I would have to boot my machine with the monitor plugged in to make it work. When going to standby (screen blanks after lock, then screen goes to standby) the monitor is switched on (LED is going white) and shortly after it will show the no-signal-message. `xrandr` claims the monitor to be existent. Unplugging and replugging does not help. Same happens when logging out to greeter. Strange in so far as when booting up, the greeter is okay with the monitor. When issuing `xset -dpms` the behaviour changes and the monitor will enter sleep and come back as expected when locking the session. Console (tty1-6) is available though at all times. (I generated the bug report with dpms set off accidentally) ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: xorg 1:7.7+19ubuntu14 ProcVersionSignature: Ubuntu 5.4.0-65.73-generic 5.4.78 Uname: Linux 5.4.0-65-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.16 Architecture: amd64 BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log' CasperMD5CheckResult: skip CompositorRunning: None CurrentDesktop: Regolith:GNOME-Flashback:GNOME Date: Thu Feb 11 09:51:33 2021 DistUpgraded: Fresh install DistroCodename: focal DistroVariant: ubuntu ExtraDebuggingInterest: Yes GraphicsCard: Intel Corporation UHD Graphics [8086:9bc4] (rev 05) (prog-if 00 [VGA controller]) Subsystem: Dell Device [1028:09c3] InstallationDate: Installed on 2021-02-10 (0 days ago) InstallationMedia: Regolith 20.04.0 1.4.1 LTS amd64 (20200511) MachineType: Dell Inc. Precision 7550 ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.4.0-65-generic root=/dev/mapper/vgregolith-root ro quiet splash vt.handoff=7 SourcePackage: xorg UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 07/15/2020 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.3.2 dmi.board.name: 090NVT dmi.board.vendor: Dell Inc. dmi.board.version: A01 dmi.chassis.type: 10 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr1.3.2:bd07/15/2020:svnDellInc.:pnPrecision7550:pvr:rvnDellInc.:rn090NVT:rvrA01:cvnDellInc.:ct10:cvr: dmi.product.family: Precision dmi.product.name: Precision 7550 dmi.product.sku: 09C3 dmi.sys.vendor: Dell Inc. version.compiz: compiz N/A version.libdrm2: libdrm2 2.4.102-1ubuntu1~20.04.1 version.libgl1-mesa-dri: libgl1-mesa-dri 20.2.6-0ubuntu0.20.04.1 version.libgl1-mesa-glx: libgl1-mesa-glx N/A version.xserver-xorg-core: xserver-xorg-core 2:1.20.9-2ubuntu1.2~20.04.1 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200226-1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1915382/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp