Suddenly unable to adjust screen brightness

Thanks for the suggestion, much appreciated. Unfortunately, it had no effect. :-(

@BUstaPimms  Do you have the NVIDIA GeForce MX 330 or only have onboard Intel Graphics?

Either way, try right-clicking an empty spot on your desktop and when the menu opens, look for either NVidia or Intel Control Panel option. Select that to open the panel and see if you can adjust the brightness (and other settings) there.

Hi RoHe,

Just Intel graphics. I opened the Intel Graphics Command Center and there's a load of options for adjusting the hue and saturation etc. and while there is an option to lower the brightness of video, there's not an option to adjust the overall brightness.

Spent almost an hour on the phone with Dell support earlier updating everything including BIOS, and still no result. They seem to think it's a hardware issue which is annoying as the system is just out of warranty. I would go for the hardware diagnosis option where you send the system to Dell for £50 and they diagnose the problem, but that service is only available to mainland UK and I live on an island in Scotland so can't do that either.

Any ideas what the hardware component would be and if I could replace it myself?

The system diagnosis of the graphics and monitor (F2 after startup) passes all tests. I'm not convinced it's hardware related but not really sure what else I can do now.

Have you installed and tried opening the Dell On-Screen Display, as was suggested above?  If it's installed but doesn't run or doesn't control brightness, you might want to fully uninstall/reboot/reinstall it.

Your PC didn't come with the optional NVIDIA GeForce MX 330?  If you're not sure, go to the Support page and enter your Service Tag. (Don't post it here.)  When it identifies your PC, look on right side under Quick Links for a link to view the factory specs.  Open that and see if the NVIDIA GeForce MX 330 is listed or not...

Did you try changing that Intel Control Panel setting, even if it says it's just for video?

Have you tried using the Display Built-in Self Test button/Input-source selection button on bottom of the display to self-test the LCD panel when PC is powered off (but not unplugged)?

Since it's an AIO, there aren't many individual components. Even if your system has a GeForce MX 330 that's not just working properly, it's hardwired to the motherboard so the whole board would have to be replaced.  Or you might need a new LCD panel, assuming this is a hardware issue, not software...

You could try resetting BIOS:

1. Reboot and start tapping F2 when you see Dell splash screen to open BIOS setup
2. Copy down all current BIOS settings, to be safe
3. Power off, unplug power cord from rear of PC
4. Press/hold power button for ~15 sec
5. Open case and remove motherboard battery (read/follow Service Manual carefully)
6. Press/hold power button for ~30 sec
7. Reinstall the battery (Time for a fresh CR2032 3-volt coin cell battery?)
8. Close up and connect mouse, monitor and keyboard
9. Reboot and try adjusting brightness...

I used to have this problem but fixed it today when I realized that my Dell Latitude did not have the 'Intel Management Engine Driver' Installed. This program is responsible for various things including varying the brightness of the screen as per the value set in the OS.

Simply download and install this onto your Dell assuming you do not have it already.
https://www.intel.com/content/www/us/en/download/682431/intel-management-engine-drivers-for-windows-10-and-windows-11.html


Hopefully this helps!

The problem was a bad BIOS/driver update went out. Not sure when, but my guess is early 2024. 

Update your BIOS and Dell drivers with the latest and reboot.

This is a major issue with dell , even your Alienware's are bad  , i'm using Alienware area 51 m. From cpu to motherboard including wires everything has changed . And this bag weighs around 20 kilo's . Did your dog stepped on a bee while making this coz you couldn't upgrade this ufo ,  you even played with your customers selling fake advertisement . Will never suggest anyone to buy any products made by dell . 

@cap_neg​ Thanks, this did the magic for me! After installing, the brightness control works now!

@Chino de Oro​ thnk u, it worked!

@Thick McRunslow​ LEGEND!  This worked for me and easy to do.  Thank you so much!

@Chino de Oro​ 

THANK YOU THANK YOU THANK YOU! This worked for me.  I spent yesterday and today on WhatApp with Dell support prior to seeing this solution. They sent me suggestions that a) did not work b) did not apply to my 'all in one' Dell Inspiron, or c) would have resulted in days of work for me ....their most recent solution was "replace the motherboard and LCD".  THANK YOU!