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Thread: Monitor Brightness

  1. #11
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    Re: Monitor Brightness

    I turnrned the brightness to minimum and then executed the command :
    sudo setpci -s 00:02.0 F4.B=FF
    but there was no change.

    lspci -nnk | grep -iA2 vga
    00:02.0 VGA compatible controller [0300]: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0106] (rev 09)
    Subsystem: Samsung Electronics Co Ltd Device [144d:c606]
    Kernel driver in use: i915

    ls /sys/class/
    ata_device devfreq i2c-adapter mmc_host rfkill spi_master
    ata_link dma ieee80211 net rtc spi_transport
    ata_port dmi input pci_bus scsi_device thermal
    backlight drm leds power_supply scsi_disk tty
    bdi firmware mdio_bus ppdev scsi_generic usbmon
    block gpio mei ppp scsi_host vc
    bluetooth graphics mem printer sound video4linux
    bsg hwmon misc regulator spi_host vtconsole

  2. #12
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    Re: Monitor Brightness

    OK.

    give the results of this command

    Code:
    ls /sys/class/backlight/*
    I am going here step-by-step cuz I don't want to make any mistakes.

    Thanks

  3. #13
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    Re: Monitor Brightness

    ls /sys/class/backlight/*

    /sys/class/backlight/acpi_video0:
    actual_brightness brightness max_brightness subsystem uevent
    bl_power device power type

    /sys/class/backlight/intel_backlight:
    actual_brightness brightness max_brightness subsystem uevent
    bl_power device power type

    /sys/class/backlight/samsung:
    actual_brightness brightness max_brightness subsystem uevent
    bl_power device power type

  4. #14
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    Re: Monitor Brightness

    ΟΚ.

    Take a look inside this file
    Code:
    cat /sys/class/backlight/intel_backlight/brightness
    and try to change the actual number and see if that affects your monitor brightness.

    eg :
    If the result of above command is 976 , then apply below commands
    Code:
    sudo -i 
    echo 800 > /sys/class/backlight/intel_backlight/brightness
    exit
    did you notice any change in monitor brightness ?

    Thanks

  5. #15
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    Re: Monitor Brightness

    Well b4 i make that change, i would like to tell you that i visited that folder and it has three files actual_brightness, brightness, max_brightness and all have the value 4648 which i got from the command :

    cat /sys/class/backlight/intel_backlight/brightness
    4648

    So what should i do next ?

  6. #16
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    Re: Monitor Brightness

    Quote Originally Posted by 3dmatrix View Post
    cat /sys/class/backlight/intel_backlight/brightness
    4648

    So what should i do next ?
    Try
    Code:
    sudo -i 
    echo 4000 > /sys/class/backlight/intel_backlight/brightness
    exit
    see if 2nd command reduces your monitor brightness.

    The idea here is to find a value that meet your needs.
    Then we can add this command in rc.local and your problem solved.

    Thanks

  7. #17
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    Re: Monitor Brightness

    Quote Originally Posted by NikTh View Post
    Try
    Code:
    sudo -i 
    echo 4000 > /sys/class/backlight/intel_backlight/brightness
    exit
    see if 2nd command reduces your monitor brightness.

    The idea here is to find a value that meet your needs.
    Then we can add this command in rc.local and your problem solved.

    Thanks
    YES ! It changes the brightness
    BUT goes back to the original value of 4648 every time i login or reboot.

    For most of my work value between 500 - 1000 is fine. For some work i might even bring it down to 100 and for some work (like watching video or playing games) it can go up to 2000 - 3000.

    Another problem that i see is : If i lower the brightness by that command and then use the keyboard shortcut to change the brightness then the brightness first 'jumps' to maximum !

    .

  8. #18
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    Re: Monitor Brightness

    Quote Originally Posted by 3dmatrix View Post
    BUT goes back to the original value of 4648 every time i login or reboot.
    We will fix that.

    Quote Originally Posted by 3dmatrix View Post
    For most of my work value between 500 - 1000 is fine. For some work i might even bring it down to 100 and for some work (like watching video or playing games) it can go up to 2000 - 3000.
    You can adjust the brightness with Fn keys combo . The problem is on boot.

    What brightness you want when you boot your PC ? What is the value ?

    Quote Originally Posted by 3dmatrix View Post
    Another problem that i see is : If i lower the brightness by that command and then use the keyboard shortcut to change the brightness then the brightness first 'jumps' to maximum !.
    This is not a problem. This is normal (happening to me too).
    When you use Fn keys , the value in /brightness first goes to max ,and then you can reduce it .

    Your only problem now , is the brightness on boot - login. Just tell me the value that meet your needs.

    Thanks

  9. #19
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    Re: Monitor Brightness

    I think 1000 should be perfect !

    When i manually try to change the value to 1000 in that file. It does not lets me change it. If i change the permission of the file then it changes and saves but the value in the file actually remains the same.

    .

  10. #20
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    Re: Monitor Brightness

    Lets try and see ..

    first open the file rc.local

    Code:
    gksudo gedit /etc/rc.local
    add bellow line , before exit 0

    Code:
    (sleep 3 ; echo 1000 > /sys/class/backlight/intel_backlight/brightness) &
    save the file and reboot your PC.

    Hopefully the brightness will be adjusted in this value when you login.

    Thanks

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