external screen blank

[pczaja]

Summary: On my dual screen setup, the external monitor doesn't work in X after the latest update.

Tested this with the external monitor connected via VGA

a) using docking station
b) using X200s internal VGA output

Booting up ubuntu works just normal. The boot screen and login prompt is mirrored on the internal and external monitors. So it does work technically and the cabling is correct.

After logging in, X kicks in and the external monitor goes blank.
System settings however shows the external monitor with correct dimensions.
Hitting "recognize screen" doesn't help.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: xorg 1:7.7+1ubuntu8.1
ProcVersionSignature: Ubuntu 4.4.0-89.112~14.04.1-generic 4.4.76
Uname: Linux 4.4.0-89-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.14.1-0ubuntu3.29
Architecture: amd64
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: Sat Aug 25 10:48:22 2018
DistUpgraded: 2017-05-13 08:46:45,733 DEBUG enabling apt cron job
DistroCodename: trusty
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller [8086:2a42] (rev 07) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:20e4]
   Subsystem: Lenovo Device [17aa:20e4]
InstallationDate: Installed on 2015-03-03 (1270 days ago)
InstallationMedia: Ubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1)
MachineType: LENOVO 7458WPW
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-89-generic root=UUID=98fb4872-8b98-469b-9c96-acbc8e4eba17 ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
UpgradeStatus: Upgraded to trusty on 2017-05-13 (469 days ago)
dmi.bios.date: 10/25/2012
dmi.bios.vendor: LENOVO
dmi.bios.version: 6DET72WW (3.22 )
dmi.board.name: 7458WPW
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr6DET72WW(3.22):bd10/25/2012:svnLENOVO:pn7458WPW:pvrThinkPadX200:rvnLENOVO:rn7458WPW:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 7458WPW
dmi.product.version: ThinkPad X200
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.11.3+14.04.20160425-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.67-1ubuntu0.14.04.2
version.libgl1-mesa-dri: libgl1-mesa-dri N/A
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
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: Fri Aug 24 23:09:28 2018
xserver.configfile: default
xserver.errors: intel(0): sna_mode_shutdown_crtc: invalid state found on pipe 1, disabling CRTC:29
xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 16400
 vendor LEN
xserver.version: 2:1.18.4-0ubuntu0.2~trusty2

[pczaja (pczaja)]

Now it works again. Had switched off external screen in display devices settings after bug appeared. Switching it on again today did the job.

[Paul White (paulw2u)]

Ubuntu 14.04 (trusty) reached end-of-standard-support on April 25, 2019.

Thanks for your comment pczaja. I'm sorry no-one responded to you over
four years ago. Will close as 'Invalid'.