A backlight is a form of illumination used in liquid crystal displays (LCDs).

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Brightness Ubuntu vs. Kubuntu and Xubuntu

On Kubuntu and Xubuntu the brightness of my monitor goes down to zero (i.e. the backlight got switched off). On Ubuntu this does not happen, the minimux brightness is still with backlight on and ...
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2k views

Can't change screen brightness running Ubuntu 14.04LTS on Samsung NP510R5E

FIXED! After DBANing my hard drive I installed Ubuntu 14.04LTS and quickly realised I've been unable to change screen brightness. This isn't too much of an issue when AC power is plugged in as the ...
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0answers
23 views

Function keys change wrong backlight file on my Acer Aspire One

Whenever I press the function keys to change my laptop's screen brightness, it modifies the value stored in the file /sys/class/backlight/acer-wmi/brightness, but my screen stays the same. With a bit ...
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0answers
311 views

I can't lower the backlight/brightness

Why I can't control the brightness/backlight level? At the first: Notebook Positivo BGH - C500 Series. Processor: AMD C60 series (dual core 800 mhz-1ghz) GPU: Radeon HD 6290 (worked with fglrx/...
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0answers
27 views

Brightness slider is too fine (14.04)

I'm running ubuntu 14.04 on a Dell laptop (XPS 13 Developer Edition). The brightness slider stopped working (the slider would fill up and empty as usual but the brightness wouldn't change). This fix ...
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0answers
623 views

*ERROR* Cannot find a backlight controller

So I just updated my kernel version on Ubuntu 15.04 64bit to Kernel 4.1.6 latest mainline. Now every boot of my laptop, I got this error. starting version 219 _ ...screen blink... starting version ...
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358 views

Backlight button not working ( Dell inspiron 14z) - 14.04

The main point is that everything was working on 12.04 but now I can only change brightness using the applet. Here's what I have done so far: Following the info provided on Ubuntu Wiki Backlight I ...
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510 views

How do I turn off the display (DPMS) without X?

I've been trying to switch off the built-in screen of a device I've got, but I can't seem to completely control it without X running. If I run a GUI (I've tried Kubuntu 12.10) and issue the command ...
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4k views

Default Keyboard brightness is not working

I am running Ubuntu 13.04 64-bit on an Asus UX31A. To control the default screen and keyboard brightness after the start, I wrote this to the rc.local: echo 0 > /sys/class/backlight/acpi_video0/...
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1k views

How to make backlight work on Acer 5732z?

I want to run 12.04 on my Acer Aspire 5732z. I know from research that these computers have issues with the backlight on Ubuntu. So I tried a couple of solutions: The sudo lightdm restart method. I ...
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0answers
2k views

Keyboard backlight support for Asus G55VW

The FN+F3 and FN+F4 key combinations are not able to control the keyboard backlight on my Asus G55VW. I could live with a command line solution so I tried the solution proposed here: http://askubuntu....
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26 views

Laptop brightness resets on opening lid?

So I just installed Ubuntu 16.04 on my laptop(fresh install) and am having an issue I did not have in Ubuntu 15.10. So I have set the When the lid is closed to Do Nothing as I don't want my laptop to ...
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56 views

thinkpad_acpi disabling brightness events

After installing routine updates, my keyboard brightness controls, wireless on/off, and other controls have stopped working. Interestingly, the 'lock' key still works. I have looked at a few other ...
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0answers
102 views

Hotkeys and slider for brightness don't work

I have an Intel processor with no graphics and Nvidia GTX980M with Nvidia driver. I just installed Ubuntu Gnome 15.10 and everything works fine except for the brightness controls. Changing both from ...
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0answers
261 views

Lubuntu MacBook no screen backlight after resume/wake

I'm running Lubuntu 15.10 on a MacBook Intel Core2Duo. After suspending/hibernating and then resuming/waking the screen's backlight does not come on. With a bright enough light, one can see what the ...
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0answers
297 views

Dell XPS 13 9343 keyboard backlight

I have just re-installed 15.04 after updating my older BIOS to a newer version, prior to this re-installation the keyboard back light was functional; however, it doesn't seem to be working anymore ...
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73 views

Ubuntu on Macbook 4,1 (pre-October 2008) Backlight Laptop Screen Issue

I cannot get Ubuntu or Ubuntu-based systems to wake from sleep properly on a Macbook 4,1 pre-October 2008. The backlight for the laptop screen does not turn back on after waking and signal does not ...
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19 views

14.04 increasing backlight above a certain level does not work

I've read every topic I came across but couldn't find a problem similar to mine. I have a laptop with ati graphics card and have fglrx installed. my function keys for increasing - decreasing ...
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122 views

Backlight control broken on 14.04 on Lenovo U310

I'm unable to change the backlight brightness under 14.04. habefaro@habefaro-Lenovo-U310:~$ uname -a Linux habefaro-Lenovo-U310 3.16.0-34-generic #47~14.04.1-Ubuntu SMP Fri Apr 10 17:49:16 UTC 2015 ...
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189 views

keyboard backlight is not working

I have just bought a new computer and I installed ubuntu on it but the problem is that I've lost my keyboard backlight here is my computer http://store.hp.com/webapp/wcs/stores/servlet/us/en/mdp/...
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166 views

SONY VAIO Turn off backlight, locked windows partition, need help downloading java SEMIDUPLICATE SOS STAT

Sony Vaio SVF15N17CXB Turn off keyboard back-light Sony (VAIO SVF1521DCXW) Hello all, Total newbie, tried to dualboot but ubuntu locked up my windows partition, my windows is locked and i need 10 ...
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134 views

Ubuntu isn't able to boot: Keyboard backlight function in Sony vaio

I have installed Ubuntu 12.04.5 alongside with Windows 7 and it's been working fine until yesterday. After choosing Ubuntu from the dual boot menu a message appears and says: "Sony Vaio: couldn't set ...
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325 views

Apple Cinema LED Display: using regular brightness controls?

I have a Dell Latitude E6430 laptop, running Ubuntu 14.04, connected to a 27" Apple Cinema LED Display (which works fine). By tweaking the appledisplay kernel module a little bit, I can even get ...
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89 views

How to use Fn+F5/F6 adjust the backlight

My NB is Asus N500JK and OS is Kubuntu 14.04. I try modify /etc/default/grub file. GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=" then update-grub After reboot, it can use Fn+F5/F6 adjust ...
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295 views

Keyboard Backlight not working

I'm using Ubuntu 12.04 on a Toshiba Satellite P775-S7100. The keyboard backlight was working initially, but after reinstalling the same version of Ubuntu it stopped working, and as far as I can tell, ...
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0answers
771 views

No laptop backlight when using AMD driver recommended by Steam

When I install the fglrx-experimental-13 driver that Steam recommends for my laptop (ATI Mobility Radeon HD 5000 Series) I have no backlight when I log in, but an external monitor works. I've tried a ...
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0answers
43 views

Problem adjusting the brightness

I'm fairly new to Ubuntu and I've managed to take care of almost everything but brightness. Right from the begining, brightness is at its peak and it's hurting my eyes by now and I have no obvious way ...
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0answers
19 views

No video after bootloader on Sony Vaio SVF15N2A4E

I have a Sony Vaio SVF15NA24E. I have been trying to get Ubuntu 16.04 installed on it alongside Windows 8.1, which works fine. However, the screen simply blanks out after the grub bootloader when ...
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0answers
35 views

How to change intel backlight to acpi_video?

In my ubuntu I can't change my brightness through nor through system setting. I found that brightness is controlled by intel card rather than acpi. Meaning in folder /sys/class/backlight I have two ...
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60 views

xbacklight - No outputs have backlight property

I am running Lubuntu 16.04 Attempting to run xbacklight -get gives me No outputs have backlight property There is only one directory in /sys/class/backlight, which is intel_backlight. I have ...
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58 views

“Cannot find a backlight controller” when normally booting Ubuntu 16.04 LTS on a Pavilion g6 Notebook

Most if not all Ubuntu backlight solutions depend on the backlight driver working. Like this one for example. In my case, when normally booting Ubuntu 16.04 LTS on a Hewlett-Packard Pavilion g6 ...
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43 views

brightness key not working after kernel update on thinkpad yoga

Used to work well under 3.13 kernel. After updating to 3.19.0-32, brightness control keys don't work. When pressed, the slider shows up with correct brightness level, but can't change the brightness ...
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0answers
71 views

Nvidia backlight/login screen/external display issue

I`m combining this three issues becauese they are probably connected with each other. 1. Backlight is not natively supported. In order to set backlight using function key on keyboard I have to add ...
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0answers
66 views

gsd-backlight-helper spamming the log after upgrade to 16.04?

Since updating to 16.04 from 14.04, I have the syslog spammed by: SEC: May 22 13:26:43 samsung-romano pkexec[21248]: gdm: Error executing command as another user: Not authorized [USER=root] [TTY=...
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54 views

Acer TravelMate P238-M Backlit keyboard Ubuntu 16.04 LTS

recently I got Acer TravelMate P238-M with the following hardware: Intel(R) Core(TM) i5-6200U CPU @ 2.30GHz 16GB RAM 256GB SSD 13,3" FHD Display Everything is working out of the box, except the ...
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0answers
47 views

The backlight brightness always set to full after I turn on my laptop

I have checked the number in /sys/class/backlight/acpi_video0/device/backlight/acpi_video0/brightness is 2, but it always set to full after I install the Nvidia driver, I have to manually adjust it ...
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0answers
44 views

Brightness not working on Lenovo Ideapad Z580 with Ubuntu 15.10

Recently upgraded from 14.04 to 15.10 Brightness control keys worked fine in 14.04 In 15.10 when pressing brightness increase or decrease keys, the screen slider pops up, but the brightness does not ...
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0answers
12 views

Keyboard flashing instead of dimming

So, I have an ASUS N56VB with ubuntu 15.10 and I encountered a problem a few days ago, my keyboard backlighting that was previously working fine now doesn't respond properly to the bright levels, it ...
0
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0answers
112 views

Lenovo Ideapad z500 keyboard/screen backlight issues

I cannot get my back-light on my keyboard to work whatsoever and the brightness of the screen only has two settings: maximum or eye scalding maximum. I have been searching forums high and low for ...
0
votes
0answers
181 views

brightness indicator doesn't change backlight brightness (15.10, Cinnamon, Nvidia GeForce GTX 970M)

the problem My laptop's brightness adjustment keys affect the brightness indicator, but do not affect the real brightness of the monitor's backlight. related facts My Ubuntu version is 15.10. My ...
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0answers
55 views

No backlight after installing ati driver

I have installed amd drivers on my laptop and since I rebooted it I have no backlight. I have tried adding acpi_backlight=vendor as a kernel parameter and using xbacklight -set xx but none of this ...
0
votes
0answers
64 views

Cannot adjust brightness on Samsung NP370R5E-A06UK running Ubuntu 15.04

The issue is in the title. I have tried this as well as the top answer here, both achieved nothing. I should note however, that if I start up (or wake up from sleep) while not plugged in, I will get ...
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0answers
52 views

Sony VAIO SVF1521 Not turn off keyboard backlight

I use ubuntu 15.10. My sony SVF1521JSTB hasn't got kbd_bakclight file in "/sys/devices/platform/sony-laptop/" path, and when I try run as root this "echo 0 | sudo tee /sys/.../kbd_backlight" command, ...
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0answers
46 views

How to turn off keyboard backlight if keyboard is broken?

My keyboard had the backlight on when it stopped working (due to spillage) and now I can't use the Fn + space to shut it off. Are there any commands or settings I can use without using the laptop ...
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0answers
89 views

Strange problem with backlight (it worked and now no more?)

EDIT : It's started working again?! i went out on friday night and i left pc ON. This morning it was working. looking in syslog i saw this : Dec 10 22:41:00 LittleHP kernel: [ 262.553256] video ...
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0answers
64 views

Original MacBook Air Running 14.04 Won't Turn on Backlight after waking

I have the original MacBook Air running Ubuntu 14.04 (Which is running really well, except for one thing.) I seem to have everything working, except waking the computer from a lid close. After I ...
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0answers
78 views

Changes in system screen brightness aren't reflected on actual screen. [Ubuntu 15.10][Laptop]

I've had this issue since 14.04.3 but I never bothered to fix it since I didn't use Ubuntu much. Pressing the brightness up/down function keys brings up the popup displaying the brightness level, ...
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votes
0answers
43 views

Problem with backlight

I always have problems with brightness control in my computer,(I have intel graphics HD 400) Until yesterday, I was running ubuntu 15.04 without problem at all. I just have to modify grub with these ...
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0answers
43 views

How to install recognized backlight software on my Toshiba Tecra R850?

I'm running Ubuntu 14.04 on VirtualBox, which seems to have emulated graphics. I can adjust my brightness and have graphics drivers installed, but Calise doesn't recognise either. It wants sysfs ...
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23 views

Set monitor backlight to minimum level during ubuntu boot

Is it possible to change the default brightness level during boot to the minimum level available.