Today I retested it with a new HDMI cable, but it still didn't work. However, I again installed an update, after which the monitor did come back alive. I have been unable to reproduce the problem ever since. Perhaps, after all, there were other factors in play, but I have no clue as to the root cause.
The update that *might* have fixed the problem: Start-Date: 2018-03-15 16:13:21 Commandline: apt upgrade Requested-By: brecht (1000) Upgrade: libcurl3:amd64 (7.55.1-1ubuntu2.3, 7.55.1-1ubuntu2.4), grub-common:amd64 (2.02~beta3-4ubuntu7.2, 2.02~beta3-4ubuntu7.3), grub2-common:amd64 (2.02~beta3-4ubuntu7.2, 2.02~beta3-4ubuntu7.3), isc-dhcp-common:amd64 (4.3.5-3ubuntu2.2, 4.3.5-3ubuntu2.3), qml-module-org-kde-solid:amd64 (5.43.0-0ubuntu1~ubuntu17.10~ppa1, 5.43.0-0ubuntu2~ubuntu17.10~ppa1), grub-efi-amd64-bin:amd64 (2.02~beta3-4ubuntu7.2, 2.02~beta3-4ubuntu7.3), firefox-trunk:amd64 (60.0~a1~hg20180311r407525-0ubuntu0.17.10.1~umd1, 61.0~a1~hg20180314r408098-0ubuntu0.17.10.1~umd1), libkf5solid5-data:amd64 (5.43.0-0ubuntu1~ubuntu17.10~ppa1, 5.43.0-0ubuntu2~ubuntu17.10~ppa1), grub-efi-amd64:amd64 (2.02~beta3-4ubuntu7.2, 2.02~beta3-4ubuntu7.3), grub-efi-amd64-signed:amd64 (1.85.2+2.02~beta3-4ubuntu7.2, 1.85.3+2.02~beta3-4ubuntu7.3), libkf5solid5:amd64 (5.43.0-0ubuntu1~ubuntu17.10~ppa1, 5.43.0-0ubuntu2~ubuntu17.10~ppa1), curl:amd64 (7.55.1-1ubuntu2.3, 7.55.1-1ubuntu2.4), isc-dhcp-client:amd64 (4.3.5-3ubuntu2.2, 4.3.5-3ubuntu2.3), libcurl3-gnutls:amd64 (7.55.1-1ubuntu2.3, 7.55.1-1ubuntu2.4) End-Date: 2018-03-15 16:13:35 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1755899 Title: Upgrade to linux 4.13.0-37-generic broke HDMI monitor Status in linux package in Ubuntu: Incomplete Bug description: After updating the kernel, my second monitor which is connected through HDMI stopped working. There is no signal detected. I am reasonably certain the kernel update is to blame. I performed an update with apt, autoremoved the previous kernel, and rebooted. After this, the monitor stayed black. Attached the relevant entries from apt history are included, indicating which packages were exactly updated. Start-Date: 2018-03-14 20:11:51 Commandline: apt upgrade Requested-By: brecht (1000) Install: linux-signed-image-4.13.0-37-generic:amd64 (4.13.0-37.42, automatic), linux-image-extra-4.13.0-37-generic:amd64 (4.13.0-37.42, automatic), linux-headers-4.13.0-37-generic:amd64 (4.13.0-37.42, automatic), linux-headers-4.13.0-37:amd64 (4.13.0-37.42, automatic), linux-image-4.13.0-37-generic:amd64 (4.13.0-37.42, automatic) Upgrade: linux-headers-generic:amd64 (4.13.0.36.38, 4.13.0.37.40), linux-libc-dev:amd64 (4.13.0-36.40, 4.13.0-37.42), linux-image-generic:amd64 (4.13.0.36.38, 4.13.0.37.40), keybase:amd64 (1.0.45-20180313160419.f0de728311, 1.0.45-20180314153959.acd706b851), linux-signed-image-generic:amd64 (4.13.0.36.38, 4.13.0.37.40), papirus-icon-theme:amd64 (20180311-2268+pkg18~ubuntu17.10.1, 20180314-2272+pkg18~ubuntu17.10.1), linux-signed-generic:amd64 (4.13.0.36.38, 4.13.0.37.40), firefox-locale-en:amd64 (59.0~b14+build1-0ubuntu0.17.10.1, 59.0+build5-0ubuntu0.17.10.1), firefox-locale-nl:amd64 (59.0~b14+build1-0ubuntu0.17.10.1, 59.0+build5-0ubuntu0.17.10.1), firefox:amd64 (59.0~b14+build1-0ubuntu0.17.10.1, 59.0+build5-0ubuntu0.17.10.1), linux-generic:amd64 (4.13.0.36.38, 4.13.0.37.40) End-Date: 2018-03-14 20:13:19 Start-Date: 2018-03-14 20:14:44 Commandline: apt autoremove Requested-By: brecht (1000) Remove: linux-image-extra-4.13.0-32-generic:amd64 (4.13.0-32.35), linux-headers-4.13.0-32-generic:amd64 (4.13.0-32.35), libbotan-1.10-1:amd64 (1.10.16-1), linux-headers-4.13.0-32:amd64 (4.13.0-32.35), linux-image-4.13.0-32-generic:amd64 (4.13.0-32.35), linux-signed-image-4.13.0-32-generic:amd64 (4.13.0-32.35) End-Date: 2018-03-14 20:15:00 ProblemType: Bug DistroRelease: Ubuntu 17.10 Package: linux-image-4.13.0-37-generic 4.13.0-37.42 ProcVersionSignature: Ubuntu 4.13.0-37.42-generic 4.13.13 Uname: Linux 4.13.0-37-generic x86_64 ApportVersion: 2.20.7-0ubuntu3.7 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: brecht 3585 F.... pulseaudio CurrentDesktop: KDE Date: Wed Mar 14 21:06:10 2018 HibernationDevice: RESUME=UUID=efdbd05c-0e51-415e-93d8-dca9b1b7fbf3 InstallationDate: Installed on 2017-10-10 (155 days ago) InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Alpha amd64 (20170926) MachineType: Notebook W65_W67RZ ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.13.0-37-generic.efi.signed root=/dev/mapper/ssd-root ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-4.13.0-37-generic N/A linux-backports-modules-4.13.0-37-generic N/A linux-firmware 1.169.3 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 05/27/2016 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 1.05.09 dmi.board.asset.tag: Tag 12345 dmi.board.name: W65_W67RZ dmi.board.vendor: Notebook dmi.board.version: Not Applicable dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: Notebook dmi.chassis.version: N/A dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1.05.09:bd05/27/2016:svnNotebook:pnW65_W67RZ:pvrNotApplicable:rvnNotebook:rnW65_W67RZ:rvrNotApplicable:cvnNotebook:ct10:cvrN/A: dmi.product.family: Not Applicable dmi.product.name: W65_W67RZ dmi.product.version: Not Applicable dmi.sys.vendor: Notebook To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1755899/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
