Brightness change automatically when i remove power cable - Lxqt

Hello :grinning:

every time when i remove or plug in the power cable from my laptop, the brightness change and my screen goes dark.

in case it’s happened and my screen is dark, the backlight(in german: Hintergrundbeleuchtung) slider is on minimum(see picture)

my current solution is, i push the slider every time to the maximum

[pycrk@ovoEnd ~]$ cat .config/lxqt/lxqt-powermanagement.conf
[General]
__userfile__=true
backlightIdleness=50
backlightIdlenessOnBatteryDischarging=true
disableIdlenessWhenFullscreen=false
enableBatteryWatcher=true
enableIdlenessBacklightWatcher=false
enableIdlenessWatcher=true
enableLidWatcher=true
idlenessACAction=-1
idlenessACTime=@Variant(\0\0\0\xf\0\r\xbb\xa0)
idlenessBatteryAction=-1
idlenessBatteryTime=@Variant(\0\0\0\xf\0\r\xbb\xa0)
idlenessTime=@Variant(\0\0\0\xf\0\0\xea`)
powerLowAction=-1
powerLowLevel=5
powerLowWarning=30
runCheckLevel=1
showIcon=true
useThemeIcons=true

i hope someone is able to help me, i don’t find any solution in the www

journalctl --since ‘20 minutes ago’

Mai 26 19:32:15 _hostname_ systemd-logind[389]: Lid opened.
Mai 26 19:32:22 _hostname_ lxqt-panel[716]: Error on DBus request(:1.53,/StatusNotifierItem): QDBusError(org.freedesktop.DBus.Error.UnknownProperty, Property org.kde.StatusNotifierItem.IconThemePath was not found in object /StatusNotifierItem)
Mai 26 19:32:22 _hostname_ lxqt-panel[716]: Error on DBus request(:1.53,/StatusNotifierItem): QDBusError(org.freedesktop.DBus.Error.UnknownProperty, Property org.kde.StatusNotifierItem.ToolTip was not found in object /StatusNotifierItem)
Mai 26 19:32:22 _hostname_ lxqt-panel[716]: Error on DBus request(:1.53,/StatusNotifierItem): QDBusError(org.freedesktop.DBus.Error.UnknownProperty, Property org.kde.StatusNotifierItem.IconName was not found in object /StatusNotifierItem)
Mai 26 19:32:34 _hostname_ lxqt-panel[716]: Error on DBus request(:1.53,/StatusNotifierItem): QDBusError(org.freedesktop.DBus.Error.UnknownProperty, Property org.kde.StatusNotifierItem.IconThemePath was not found in object /StatusNotifierItem)
Mai 26 19:32:34 _hostname_ lxqt-panel[716]: Error on DBus request(:1.53,/StatusNotifierItem): QDBusError(org.freedesktop.DBus.Error.UnknownProperty, Property org.kde.StatusNotifierItem.ToolTip was not found in object /StatusNotifierItem)
Mai 26 19:32:34 _hostname_ lxqt-panel[716]: Error on DBus request(:1.53,/StatusNotifierItem): QDBusError(org.freedesktop.DBus.Error.UnknownProperty, Property org.kde.StatusNotifierItem.IconName was not found in object /StatusNotifierItem)
Mai 26 19:32:34 _hostname_ lxqt-powermanagement[1303]: BatteryChanged discharging: false chargeLevel: 26.4421 actionTime: QTime(Invalid)
Mai 26 19:32:34 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "3 minute(s)" , 3
Mai 26 19:32:34 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "5 hour(s)" , 5
Mai 26 19:32:34 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "3 minute(s)" , 3
Mai 26 19:32:34 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "5 hour(s)" , 5
Mai 26 19:32:34 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "3 minute(s)" , 3
Mai 26 19:32:34 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "5 hour(s)" , 5
Mai 26 19:32:34 _hostname_ lxqt-powermanagement[1303]: BatteryChanged discharging: false chargeLevel: 26.4421 actionTime: QTime(Invalid)
Mai 26 19:32:37 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "28 minute(s)" , 28
Mai 26 19:32:37 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "1 hour(s)" , 1
Mai 26 19:32:41 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "28 minute(s)" , 28
Mai 26 19:32:41 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "11 hour(s)" , 11
Mai 26 19:32:41 _hostname_ lxqt-powermanagement[1303]: BatteryChanged discharging: false chargeLevel: 26.5895 actionTime: QTime(Invalid)
Mai 26 19:32:46 _hostname_ lxqt-panel[716]: Error on DBus request(:1.53,/StatusNotifierItem): QDBusError(org.freedesktop.DBus.Error.UnknownProperty, Property org.kde.StatusNotifierItem.IconThemePath was not found in object /StatusNotifierItem)
Mai 26 19:32:46 _hostname_ lxqt-panel[716]: Error on DBus request(:1.53,/StatusNotifierItem): QDBusError(org.freedesktop.DBus.Error.UnknownProperty, Property org.kde.StatusNotifierItem.ToolTip was not found in object /StatusNotifierItem)
Mai 26 19:32:46 _hostname_ lxqt-panel[716]: Error on DBus request(:1.53,/StatusNotifierItem): QDBusError(org.freedesktop.DBus.Error.UnknownProperty, Property org.kde.StatusNotifierItem.IconName was not found in object /StatusNotifierItem)
Mai 26 19:33:12 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "21 minute(s)" , 21
Mai 26 19:33:12 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "1 hour(s)" , 1
Mai 26 19:33:12 _hostname_ lxqt-powermanagement[1303]: BatteryChanged discharging: false chargeLevel: 26.9263 actionTime: QTime(Invalid)
Mai 26 19:33:42 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "5 minute(s)" , 5
Mai 26 19:33:42 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "1 hour(s)" , 1
Mai 26 19:33:42 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "5 minute(s)" , 5
Mai 26 19:33:42 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "1 hour(s)" , 1
Mai 26 19:33:42 _hostname_ lxqt-powermanagement[1303]: BatteryChanged discharging: false chargeLevel: 27.4316 actionTime: QTime(Invalid)
Mai 26 19:34:12 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "3 minute(s)" , 3
Mai 26 19:34:12 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "1 hour(s)" , 1
Mai 26 19:34:12 _hostname_ lxqt-powermanagement[1303]: BatteryChanged discharging: false chargeLevel: 27.9579 actionTime: QTime(Invalid)
Mai 26 19:34:19 _hostname_ lxqt-config-brightness[5265]: No outputs have backlight property
Mai 26 19:34:19 _hostname_ lxqt-config-brightness[5265]: Found output: "eDP"
Mai 26 19:34:19 _hostname_ lxqt-config-brightness[5265]: Output: "eDP" added
Mai 26 19:34:19 _hostname_ lxqt-config-brightness[5265]: Found output: "HDMI-A-0"
Mai 26 19:34:19 _hostname_ lxqt-config-brightness[5265]: Output is not connected
Mai 26 19:34:19 _hostname_ lxqt-config-brightness[5265]: Found output: "eDP"
Mai 26 19:34:19 _hostname_ lxqt-config-brightness[5265]: Output: "eDP" added
Mai 26 19:34:19 _hostname_ lxqt-config-brightness[5265]: Found output: "HDMI-A-0"
Mai 26 19:34:19 _hostname_ lxqt-config-brightness[5265]: Output is not connected
Mai 26 19:34:42 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "2 minute(s)" , 2
Mai 26 19:34:42 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "1 hour(s)" , 1
Mai 26 19:34:42 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "2 minute(s)" , 2
Mai 26 19:34:42 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "1 hour(s)" , 1
Mai 26 19:34:42 _hostname_ lxqt-powermanagement[1303]: BatteryChanged discharging: false chargeLevel: 28.4632 actionTime: QTime(Invalid)
Mai 26 19:35:12 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "2 minute(s)" , 2
Mai 26 19:35:12 _hostname_ lxqt-powermanagement[1303]: QString::arg: Argument missing: "1 hour(s)" , 1
Mai 26 19:35:12 _hostname_ lxqt-powermanagement[1303]: BatteryChanged discharging: false chargeLevel: 28.9684 actionTime: QTime(Invalid)

I think the issue might be in these lines. Do you have anything connected to HDMI-A? Is your Laptop eDP?
I haven’t run LXQt on my Laptop in a while but didn’t face your issue when I ran it.

1 Like

Why don’t you post your system info, so we can do better assumptions? :wink:

Currently discovered with my Magic Crystal Ball:

  • Removing power cable means it is a laptop.
  • Removing power from laptop, changes the power profile from AC to battery
  • Instead of looking into Brightness settings, you should look into Power settings, unless Brightness settings include power profiles separately.
  • Topic title is confusing, if the previous Magic Ball info is true. Brightness should change automatically, when removing power. Maybe you wanted a different low level for battery power profile?
2 Likes

i have added

acpi_backlight=video

in /etc/default/grub in the line GRUB_CMDLINE_LINUX_DEFAULT

after this i run the command:

grub-mkconfig -o /boot/grub/grub.cfg

and reboot my system. it works.

1 Like

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