Public bug reported:
I installed Kubuntu 26.04 on my Lenovo Legion laptop (NVIDIA graphics) and
experienced severe screen flickering.
Key behaviors observed:
• The panel natively runs at 165.04Hz.
• Forcing the refresh rate down to 60Hz via kscreen-doctor temporarily improved
the flickering but did not resolve it.
• Forcing "Discrete Graphics" in the BIOS resulted in a total black screen upon
OS load.
• Crucial Hardware Link: Lowering the screen brightness manually to 30% reduces
the flickering to minimal/manageable levels, suggesting a
power-delivery/backlight voltage or PWM conflict with the modern kernel's
power-saving features.
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: linux-image-7.0.0-38-generic 7.0.0-38.38
ProcVersionSignature: Ubuntu 7.0.0-38.38-generic 7.0.14
Uname: Linux 7.0.0-38-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.34.1-0ubuntu0.1
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC1: jgw 1549 F.... pipewire
jgw 1561 F.... wireplumber
/dev/snd/controlC0: jgw 1561 F.... wireplumber
/dev/snd/seq: jgw 1549 F.... pipewire
CasperMD5CheckResult: unknown
CurrentDesktop: KDE
Date: Fri Oct 9 19:23:43 2026
InstallationDate: Installed on 2026-10-07 (2 days ago)
InstallationMedia: Kubuntu 26.04.1 LTS "Resolute Raccoon" - Release amd64
(20260826.1)
MachineType: LENOVO 82TF
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-38-generic
root=UUID=3ad3b9bb-66ac-4411-a956-601a55f3254c ro quiet splash pcie_aspm=off
acpi_backlight=native
PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No
PulseAudio daemon running, or not running as session daemon.
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/03/2025
dmi.bios.release: 1.58
dmi.bios.vendor: LENOVO
dmi.bios.version: JYCN58WW
dmi.board.asset.tag: No Asset Tag
dmi.board.name: LNVNB161216
dmi.board.vendor: LENOVO
dmi.board.version: SDK0T76461WIN
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Legion S7 16IAH7
dmi.ec.firmware.release: 1.55
dmi.modalias:
dmi:bvnLENOVO:bvrJYCN58WW:bd03/03/2025:br1.58:efr1.55:svnLENOVO:pn82TF:pvrLegionS716IAH7:rvnLENOVO:rnLNVNB161216:rvrSDK0T76461WIN:cvnLENOVO:ct10:cvrLegionS716IAH7:skuLENOVO_MT_82TF_BU_idea_FM_LegionS716IAH7:pfaLegionS716IAH7:
dmi.product.family: Legion S7 16IAH7
dmi.product.name: 82TF
dmi.product.sku: LENOVO_MT_82TF_BU_idea_FM_Legion S7 16IAH7
dmi.product.version: Legion S7 16IAH7
dmi.sys.vendor: LENOVO
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute wayland-session
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https://bugs.launchpad.net/bugs/2170396
Title:
Lenovo Legion screen flickering on Kubuntu 26.04 (Fixed by lowering
brightness / 165Hz conflict)
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