Display Brightness hotkeys F3/F4 are not working correctly.

[Graham_Ashley]

System is an HP EliteBook 850 G5 NoteBook PC. Win 10 Pro. v21H2 19044.1826
The Display Brightness hotkeys F3/F4 are not working correctly.
At bootup, just after the initial HP logo closes, my system would continue to startup but my display just goes black.
I found that if I tapped the F4 Key (brightness up) the display appeared and there it was waiting at the Windows Login screen.
Testing those two keys, with the the brightness set to max, I can only reduce that brightness (using the F3 key) by about half way down the slider before the display just goes black. If I tap F4 several times the the screen comes back on again at full brightness.
The system has the HP Software Framework installed but no HP Hotkeys installed nor available from the HP site. All other 'Hotkey' functions are working correctly.
I am assuming if I can locate and reinstall the Hotkeys software it would resolve this problem (?)
Hoping someone can help get this resolved.

[Paul_Tikkanen]

Hi:

I don't know why HP does not have the driver on your notebook's support page.

This should be the Hotkey support driver you need:

Driver - HP EliteBook 850 G4 Notebook PC | HP® Customer Support

If you look at the list of supported platforms, the 850 G5 is supported by the driver.

https://support.hp.com/soar-attachment/17/col91831-ob-267958-1-ob-267958-1_sp112462_releasedoc.html 

[Graham_Ashley]

Thanks for replying promptly Paul.

I'm not sure either why that version is not appearing on the HP Support site for this system. It's odd. I let the site ID my system and it has always done a great job.

I have now installed sp112462 but problem persists (it's only with brightness keys F3/F4 not working correctly).

It does not state successfully installed but installs without any obvious error and on rebooting the system it did some updating as part of the startup process.

The HP Hotkeys entry does not appear in the 'Installed Programs' display but when I look in Services the 'HP Hotkey UWP Service' is running on the system. For good measure, I stopped and restarted the service but no change.

I think that is telling me the problem is not related to the HP Hotkey feature. 

At this stage, I'm unsure where to go from here - but am thinking this could be a Hardware issue.

[Paul_Tikkanen]

You're very welcome. 

Sorry that installing the Hotkey software didn't resolve the problem. 

You may be right about it being a hardware issue.

Other than reinstalling W10, I don't have any other suggestions for you to try. 

[Graham_Ashley]

Yes agree - I'm going to look more closely at the Graphics card driver firstly but am probably looking at a clean install sadly.

[Paul_Tikkanen]

There is also the cloud recovery tool option.

Driver - HP EliteBook 850 G5 Notebook PC | HP® Customer Support

I have attached the instructions for how to use that utility.

On page 11, it tells you how to add the drivers and software after the cloud recovery client - created USB flash drive reinstalls W10.

[Graham_Ashley]

Thanks for advising that option and the reader Paul.

I restored the system back to the clean install image I took when I received the system and the problem persists. 

I recently purchased the this device (ex-corporate lease) from a reputable supplier who gave it a 12month warranty. They have accepted to repair the device under the warranty and so I decided to pass it back to them to resolve - especially as it may be a hardware issue.

Am looking forward to hearing back from them within the week and having the system back.

For completeness, I will update this record with the outcome once it gets resolved. It may just help others in the future.

Thank you for your help in getting me this far.

Graham.

[Paul_Tikkanen]

You're very welcome, Graham.

Hopefully, the service center will be able to fix the problem for you.

Cheers,

Paul

[Graham_Ashley · Accepted solution]

Update:

Service technician confirmed the problem and determined it was due to a fault with the screen / display.

He replaced the display screen and testing confirmed the issue is resolved!

I restored the system image and all is working as it should.

Fantastic!

Thanks!