Can't login after lock screen (black screen)

[efficks]

After locking screen and as a result the monitor going into sleep mode, I can't get the login screen anymore, the monitor stays in sleep mode forever.

In previous Ubuntu versions after pressing any key or the mouse, the login screen showed up, but not anymore. I have to do a Ctrl+Alt+Backspace

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: xorg 1:7.7+13ubuntu3
ProcVersionSignature: Ubuntu 4.10.0-27.30~16.04.2-generic 4.10.17
Uname: Linux 4.10.0-27-generic x86_64
.tmp.unity_support_test.0:

ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
BootLog: /dev/sdc5: clean, 307593/23363584 files, 5157711/93435648 blocks
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
CurrentDesktop: Unity
Date: Wed Jul 26 11:47:17 2017
DistUpgraded: Fresh install
DistroCodename: xenial
DistroVariant: ubuntu
EcryptfsInUse: Yes
ExtraDebuggingInterest: Yes, including running git bisection searches
GraphicsCard:
 NVIDIA Corporation GK107GL [Quadro K2000] [10de:0ffe] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: Hewlett-Packard Company GK107GL [Quadro K2000] [103c:094c]
InstallationDate: Installed on 2017-07-17 (8 days ago)
InstallationMedia: Ubuntu 16.04.2 LTS "Xenial Xerus" - Release amd64 (20170215.2)
MachineType: Hewlett-Packard HP Z620 Workstation
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.10.0-27-generic root=UUID=5db25c2a-88a7-429c-9a7d-445e7694f7d6 ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/01/2013
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: J61 v03.18
dmi.board.asset.tag: 2UA33318D4
dmi.board.name: 158A
dmi.board.vendor: Hewlett-Packard
dmi.board.version: 0.00
dmi.chassis.asset.tag: 2UA33318D4
dmi.chassis.type: 6
dmi.chassis.vendor: Hewlett-Packard
dmi.modalias: dmi:bvnHewlett-Packard:bvrJ61v03.18:bd07/01/2013:svnHewlett-Packard:pnHPZ620Workstation:pvr:rvnHewlett-Packard:rn158A:rvr0.00:cvnHewlett-Packard:ct6:cvr:
dmi.product.name: HP Z620 Workstation
dmi.sys.vendor: Hewlett-Packard
version.compiz: compiz 1:0.9.12.2+16.04.20160823-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.70-1~ubuntu16.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 12.0.6-0ubuntu0.16.04.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 12.0.6-0ubuntu0.16.04.1
version.xserver-xorg-core: xserver-xorg-core N/A
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati N/A
version.xserver-xorg-video-intel: xserver-xorg-video-intel N/A
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau N/A
xserver.bootTime: Wed Jul 26 11:43:34 2017
xserver.configfile: default
xserver.devices:
 input Power Button KEYBOARD, id 6
 input Power Button KEYBOARD, id 7
 input USB CAT5 KEYBOARD, id 8
 input USB CAT5 MOUSE, id 9
 input HP WMI hotkeys KEYBOARD, id 10
xserver.errors:
 Failed to load module "nvidia" (module does not exist, 0)
 Failed to load module "nvidia" (module does not exist, 0)
xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.18.4-1ubuntu6.1~16.04.2
xserver.video_driver: nouveau

[Paul White (paulw2u)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. We are sorry that we do not always have the capacity to review all reported bugs in a timely manner.

Ubuntu 16.04 (xenial) reached end-of-standard-support on April 29, 2021.

I'm setting the status of this bug to 'Incomplete' as it's not seen any activity for some time. If this bug report has any relevance when using a currently maintained release of Ubuntu then please let us know which one(s) otherwise this bug report can be left to expire in approximately 60 days time.

[Launchpad Janitor (janitor)]

[Expired for xorg (Ubuntu) because there has been no activity for 60 days.]