XPS 14 L421X Can't adjust screen brightness


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XPS 14 L421X Can't adjust screen brightness

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My Dell XPS 14 L421X is now a week old, and I have an other problem with it.......

I can't adjust the screen brightness.

Whatever I use the Fn F4 et F5 keys (the indicator appears and move correctly but screen is always the same) or the charm brightness slider, or the power plan settings, or the advanced power settings with percentage, none of these options works. My screen brightness does not change.

When I go into the Bios, I can change the brightness using the Fn keys.

I've seen several thread about the same issue but could find a solution to work correctly. I've updated my bios (which was A09 to A12) even if in the driver page of my service tag I couldn't see the update (I had to choose "show all driver for you product").

I wanted to update the chipset and the video cards driver, but when I look at the version already installed on the computer they seems newer, and when I tried anyway to update the chipset it crashed and the computer wanted to restart (blue screen saying it but stuck at 0%) and I had to shut it down manually.

Does anyone has a fix for this situation. It really look like that there is an incompatibility of drivers but I couldn't put a finger on it.

My chipset version is HM77:

Intel HD 4000:

And Nvidia GT630m:

Thanks you very much for you help.


All Replies
  • Hi Petrolheader,

    The drivers which are already in the system would have got installed through windows update. Please uninstall the video driver through programs and features and from device manager, follow the steps below.

    Start > in search box type in programs and features > select the Intel and NVidia GT630 driver right click on it and uninstall. Restart your computer.

    You need to uninstall the Intel and NVidia driver from device manager. Please follow the steps below.

    Start > in search box type in device manager > under the video > select the Intel and NVidia driver and right click on it and uninstall and check the box (delete the software for this device). Restart your computer and then update the chipset driver, use the link below.


    Once the chipset driver is installed in your computer, you can install the Intel HD 4000 and NVidia driver using the link below.

    http://dell.to/Tiu6Jf  Intel driver

    http://dell.to/VayjEK  nvidia driver

    Please do reply for further assistance.

    Thanks and regards,
    Senthil S
    To know more about Dell Product Support, Drivers & Downloads, Order & Dispatch status -> choose your region US / India . For Dell support videos click here.

  • HI.

    Thanks for the answer.

    I'm on windows 8 but I've figured out how to follow your instructions.

    I've uninstalled the drivers from the add&remove and from the device manager.

    I've then updated the chipset. And tried to reinstall the graphic drivers.

    I've installed the Nvidia GT 630 driver, however I couldn't install the intel driver.

    The system was saying that my system does not have the mininal configuration required.

    Anyhow there was an intel driver that had been auto installed on restart and I've been able to adjust the screen brightness.

    But, while writing this answer something happens, screen changed and drivers seems to have been updated automatically.

    The computer asked me to restart after a configration. And I now can not adjust the brightness anymore.

    How can I prevent windows to auto update the drivers if they does not fit my computer ?

    Honestly I think there is a bit too much to do for a brand new comuter, just to get it working properly.

    Anyhow thank you very much for your help.

  • If I can give you more information, I know a little bit more how to reproduce the problem.

    As soon as I uninstall the intel HD 4000 driver from the add&remove of the configuration panel, I can adjust the brightness.

    Then when I go in the device manager (where the HD4000 graphic still is) and if I uninstall it, windows do some auto install.

    It first reinstall (automatically without asking anything) the graphic card HD 4000 driver (with WDDM 1.2 at the end of the name in the device manager) and the brightness adjustement still works.

    But a few seconds later, it change again (the screen goes black, then on again) and seems to update the driver to "Intel HD Graphics 4000", and the brightness slider stop working.

    And at the "first" auto installation of the driver there is no Intel driver in the programm list of the config panel, but it appears during the "second" auto installation.

    I don't know if I'm clear enough, because it is a bit difficult to explain (and actually weird enough) but I don't know how to prevent windows for doing all these things by itself.

    Thanks again for your time.

  • Re Hi.

    I have good news. I think I have figured out how to solve everything.

    I made a big mistake since the beginning. I was looking at the driver list on the dell support site without noticing that Windows 7 was selected above the list. And you gave me links for Win7 also as I didn't tell which system I was using.

    I thus had only drivers for windows 7. And even if there is in the detail of each driver a compatibility list that say windows 8, it seems that they are not compatible.

    I saw this when I was looking for older versions, and found the "all operataing systems" button. I then choose the HD4000 driver for windows 8, which is only the, A01, Graphic_Intel_W84_X08_A01_setup_CPFJ5_ZPE.

    I was able to install this one because my system now meet the requirements.

    And I can now adjust the brightness.

    I will update the Nvidia card with the correct driver also.

    I don't know what put the mess at the beginning since I never updated anything by myself, but I will look into the windows update if it comes back by this door.

    Windows 8 is killing me lately. :/

    Thanks for putting me in the right direction.


  • Hi Senthil.

    The chipset driver you recommended is for Windows 8, however the Intel and Nvidia drivers you recommended are for Windows 7. Are the Win7 drivers compatible with Win8?

    I ave the same problem as indicated above, cannot adjust brightness on a brand new XPS 14 inch, and would like to know what is the correct procedure with deleting/installing the drivers to sort out the issue.



  • Hi from Colombia

    I have the same problem in the same computer, a Dell ultrabook XPS L421X and after two weeks using this i can't change the brightness.

    I followed all the steps but don't work.

    Any other solution?


  • Add me to the list of people with this problem. Only occurred after i updated the BIOS to A14 and Windows 8.1 so I can't pinpoint when this happened.

  • Same issue here.

    After having installed 8.1

    Using Intel

    The weird thing is that when I try to change the brightness using the Fn+F5, I see two pictograms to adjust brightness. One at the minimum on the top left corner and one at the maximum in the bottom center.

    So I guess something is wrong in my setup.

    If someone have an idea...

  • I seem to have fixed this by uninstalling the intel grahics driver and reinstalling an older version from her..


    It promted me to say that I have newer drivers available but I told it to continue anyway and after a restart all seems well again. 

    Try it

  • Miracle. I did something even simpler

    1. Uninstall the intel driver. Check the box telling to delete the driver files
    2. Reboot
    3. Ta-da!