HP EliteBook 840 G6 brightness keys not working

[ric-cz]

Hi, I have an issue with my HP EliteBook 840 G6: the brightness keys F3 and F4 don't work. Other keys such as MUTE, Volume Up, Volume down, Numlock, WiFi (Airplane mode) toggle work fine, including an OSD bar.
My system is Windows 10 x64 21H2 with the latest BIOS.
So far I have tried:
Disable/Enable PnP monitor in Device manager
Unistall/Install display adapter drivers
Update all the possible drivers (incl. the graphics driver)
Also installed these from hp support page
- HP Collaboration Keyboard Software
- HP Support Assistant
- Essential System Updates for Microsoft Windows 10
- HP Application Enabling Software Driver

Went through various support forums and tried to find HP Hotkey Support Driver. Currently, there's no such thing as HP Hotkey Support for my laptop, in fact it seems that hp removed this driver from their website completely for any hp laptop.

[Paul_Tikkanen]

Hi:

The only suggestion I can offer would be to try the HP Hotkey support driver from the Elitebook 840 G5...

Type:

Driver-Keyboard, Mouse and Input Devices

Version:  8.10.14.1 Rev.A

Operating systems:

Windows 10 (64-bit)

Release date:  Jun 29, 2021

File name:  sp115288.exe

[ric-cz]

Thank you for your effort. After several hours and dozens of gray hair I've managed to find HP Hotkey support driver for the Elitebook 840 G6 here:

https://support.hp.com/th-en/document/c06383477

But guess what -  it didn't help. So I tried your file for the G5 and that didn't work either. I'll try clean install of Windows, maybe my system is somehow broken. If I succed I'll post it here.

I've noticed that F1 for video output switching and F8 for turning the microphone off/on doesn't work either, so it fully matches the description of the /document/c06383477.

[ric-cz]

So my findings are that it is caused by Windows updates. I have system bit copy from August 2021 and after restoring this backup, all keys incl. F3/F4 for brightness work just fine. But I there are pending updates now waiting to be installed and after restart I guess I'm back where I started. **bleep**.

[Paul_Tikkanen]

You're very welcome.

If you can figure out what Windows update is causing the Hotkeys not to work properly, you can use the Hide Windows Update utility that I zipped up and attached below to prevent the offending update from showing up and installing, after you uninstall it.

One other last resort would be to try this app from the Microsoft Store...

Get HP System Information - Microsoft Store

[ric-cz]

So I can confirm that it is caused by Windows update, but don't know which update specifically. My backup is 21H1 from August 2021, where everything works fine. But as soon as 21H1 got updated, F1 for display switch, F3/F4 for brightness and F8 for microphone stops working. During the update I noticed that screen flashed several times so graphics drivers were definitely updated too. I tried the newest drivers from intel website (newer drivers than those on G6's support page.) No luck. Upgrade to 21H2 didn't help either, nor sp115288.exe or SP96016.exe.

I tried suggested HP System Information app and there's something wrong with it. It opens a window but there's no values, only names. All I see is:

Product name

Product number

Software build

Memory

...

[ric-cz · Accepted solution]

I found a solution today, I hope it's not temporary and no updates will break it this time.  You need HP Hotkey Support Driver for hp ProBook 640 G5. This driver has about 56MB and the installation requires system restart.

I don't have privileges to post files here, so if anyone needs this, hurry up, it's still on hp ProBook 640 G5 support page under

https://support.hp.com/us-en/drivers/selfservice/hp-probook-640-g5-notebook-pc/27391185

Software-Solutions

HP Hotkey Support 6.2.53.1 Rev.A 53.4 MB Aug 22, 2019