brightness control by fn+f9 & fn+f10 is not working

[saddamhossain22]

Hello all I am facing a problem with fn key. Yesterday I have installed windows 10 64 bit in my notebook. Everything was working perfectly before I installd the windows but now my brightness controlling using fn key is not working, other keys are working by fn key. I have tried too much but cannot solve it please help me thank you in advanced

[saddamhossain22]

Pls all help me

[Barachiel · Accepted solution]

Hi @saddamhossain22 ,

Thank you for posting on HP Forums,

The Barachiel is at your service.

I understand you are in need of support,

I'll be glad to help you out, however, for an accurate solution I will need more details:

Have you attempted any steps on your own before posting on the HP Forums?

When was the last time it worked without these issues? 

In the meantime, please try the steps mentioned on this link: Click here

Please reply with the details for further assistance.

Eager to help!

[saddamhossain22]

Its very glad to inform you that my issue has been solved

[MKazi]

@saddamhossain22

Hi,

as @Barachiel is out of the office today, I'm replying to you. 

I'm glad that the issue has fixed and hope it stays that way.

Wishing you a great year ahead! 🙂

[pumi]

Hi, I tried lot of things but the Fn+F9 and the Fn+F10 key combinatons stil not control my display's brightness.

I use HP ElitBook 840 G1 and all the latest driver and software is up to date, and I use the latest Windows 10 64bit.

I am following the steps on the link you wrote, but the right click on the desktop, open settings and scroll for the brightness settings with touchpad or mouse is not an option for me when there was a dedicated key for this.

If can somebody please help me what did I wrong.

[euresko]

Its probably something in your BIOS. If you have recently updated the BIOS of if the BIOS was set to defaults the fn+brightness doesn't work. I posted a detailed answer to someone's questions about this in January 2018 but the post is gone.... please check your BIOS, there is a setting in there to disable the fn+brightness keys, and that needs to be switched back so that it will work. Sorry I cannot be more specific. 

[pumi]

Hi,

Thank you for your answer.

I am using the latest BIOS version. I can not found specific settings at BIOS, everything is enabled on it.

I found when my laptop wake up from sleep mode the most of cases the brightness control keys not working.

When I completly restart the computer, the brightness control keys works well, when not connected external monitor.

I think there is something wrong in the Windows 10 sleep mode's handlers or with the backend systems.

[euresko]

I found my notes from last time...

I had this same issue on this 840 g2 laptop, after reloading Windows 10, and installing all sorts of different versions of the drivers on HP website. What is special about my laptop version is that it has Intel CPU graphics and AMD chip for some extra graphics options, not all of these 840 g2 models have dual video chips.

This is what fixed this for me:

In the BIOS there is an option under the "Advanced" tab, Scroll down to the "Hybrid Graphics" checkbox, and UNCHCEK that box. If you are having this issue, this simple thing could fix it for you. What that does is enable the AMD graphics chip, and when that is enabled it will interfere with the fn-f9/fn-f10 options to dim the screen. If you don't have that option then you don't have dual video chips, and your issue is probably drivers with the video and/or hotkey software.

If you are reloading your operating system, you will need to go to the HP support site to download drivers. You will need to download the Intel display drivers and the Hotkey drivers. I used the most recent version: sp79336 (video), and sp79266 (hotkey). Make sure to reboot after installing the hotkey software.

For the fn-f8 hotkey, that is a "mute microphone" option, and that is probably controlled by the audio drivers and the hotkey software. So if that is an issue, that might be related to the audio drivers, may need to uninstall them, reboot, and installed the most recent version from the HP support site for drivers. Maybe even reinstall the hotkey drivers after doing the audio. Make sure to reboot after installing the hotkey software.

None of the advice on these forums was helpful, I just figured this out on my own. Hopefully this will help someone.

[IZee25]

When I try to click on that link the website says that there's an error. Can you please help because I want to fix my brightness keys. I have a ProBook 6475b by the way.