Public bug reported:
### Issue
I have a PC connected to an LG 27GL850-B Ultragear QHD monitor. When I launch
Ubuntu, the LG screen displays a black screen by default. If I change the
refresh rate from 144hz to 120hz the monitor will work correctly.
### Expected behavior
The monitor should be configured to display correctly by default.
### System Info
* OS: Ubuntu 26.04 LTS
* Hardware Model: ASUS TUF GAMING B550M-PLUS _WI-FI_
* Processor: AMD Ryzen™ 5 5600X × 12
* Graphics: zink Vulkan 1.4(NVIDIA GeForce RTX™ 4070 SUPER (NVK AD104))
* Firmware Version: 3621
* Kernel Version: Linux 7.0.0-14-generic
### XOrg version
xorg:
Installed: (none)
Candidate: 1:7.7+26ubuntu1
Version table:
1:7.7+26ubuntu1 500
500 http://archive.ubuntu.com/ubuntu resolute/universe amd64 Packages
### Extra info
* I am booting Ubuntu off an unmodified USB image in "Try Ubuntu" mode
* I have two monitors connected. The 144hz LG connected via DisplayPort and a
60hz Dell connected via HDMI
* The same issue occurred when booting my PC on Linux Mint
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: xorg (not installed)
ProcVersionSignature: Ubuntu 7.0.0-14.14-generic 7.0.0
Uname: Linux 7.0.0-14-generic x86_64
NonfreeKernelModules: zfs
ApportVersion: 2.34.0-0ubuntu2
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 26.04.2
CloudArchitecture: x86_64
CloudID: nocloud
CloudName: unknown
CloudPlatform: nocloud
CloudSubPlatform: seed-dir (/var/lib/cloud/seed/nocloud)
CurrentDesktop: ubuntu:GNOME
Date: Mon Jul 27 22:34:47 2026
LiveMediaBuild: Ubuntu 26.04 "Resolute Raccoon" - Release amd64 (20260423.1)
ProcEnviron:
LANG=C.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
XDG_RUNTIME_DIR=<set>
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
** Affects: xorg (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute wayland-session
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2161930
Title:
LG Monitor shows black screen when set to 144hz
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/2161930/+subscriptions
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
