wandering brightness

Hello,
This is a different laptop than I normally use but a WIN11 HP that is relatively
new and ran well, but i left it sit for a while and the battery evidently depleted,
upon startup a week ago it had a corrupted BIOS error pop up with a message
restoring the default BIOS or something to that effect, then it started and has
worked well ever since except the brightness diminishes as time goes on.

I went to system, display, brightness based on content OFF, night light OFF, I am wondering if a BIOS setting can be used to fix this minor issue.
I am not up on logging or anything too technical, I am just a normal user who knows enough about laptops to get by and that's about it.
Thank you.
BIOS AMI F-07, 7/19/2023
SMBIOS Version 3.3
BIOS Mode UEFI

HP Pavillion Laptop 14z-ec100
8GB DDR4
256GB SSD

Device name
Processor AMD Ryzen 5 5625U with Radeon Graphics (2.30 GHz)
Installed RAM 8.00 GB (7.34 GB usable)
Device ID 42568A98-D50A-4525-A7DC-DB654749E8E3
Product ID 00330-90004-58810-AB843
System type 64-bit operating system, x64-based processor
Pen and touch No pen or touch input is available for this display

Edition Windows 11 Pro
Version 25H2
Installed on ‎4/‎11/‎2025
OS build 26200.8037
Experience Windows Feature Experience Pack 1000.26100.300.0

can you show or transcribe the BIOS error?

Maybe you have auto brightness set?

Disable Adaptive Brightness via Settings

Go to Settings → System → Display.

Look for “Change brightness automatically when lighting changes” or “Automatically adjust brightness” and toggle it off.

Thank you for the reply. I don't have the BIOS error other than I remember the machine waited unusually long to boot after a long nap, and came up with corrupted bios error then proceeded to restore BIOS on its own,
Here is a snip of the brightness settings I can find in system/display/

Those are the only settings I can find pertaining to brightness, for some reason.

Maybe it is in your power plan. When the screen dims, does plugging the power in make a difference?

Plugged in all the time but i will go look at the plan....I forgot about checking that . thanks

Here is what I have in control panel/power options :

Its been a great little laptop used for occasionally tuning vehicles, the only other issue it has, and has had since day 1 is the battery depletes pretty fast in an hour or maybe 2 at the most unplugged no matter how many things i turn off based on the advice i get. But i just live with that

joe2989 said:

Its been a great little laptop used for occasionally tuning vehicles, the only other issue it has, and has had since day 1 is the battery depletes pretty fast in an hour or maybe 2 at the most unplugged no matter how many things i turn off based on the advice i get. But i just live with that

Click to expand...

It is easy to fit a new battery and costs about £30

I will have to see how the batteries go in these new type laptops I am not familiar with, with build in drives.
Thanks

Ok, new info here.... the brightness held while machine was on and logged in, I turned it off for 15 minutes and it went to about 2/3rds brightness upon restart. The same as it did after i left it off all night, and always plugged in... so hmmmm

I wonder if this is down some HP software trying to eke out the battery?

I don't allow most of that HP stuff to start, but it wouldn't surprise me. It didn't do this before the BIOS OD'd from sitting turned off too long.

I went to device manager and uninstalled AMD Radeon Graphics, no change on restart. I went to control panel /power settings / advanced, and put the throttle to the wood and no change on startup, still starts at 2/3rds brightness. So, i set it to factory default on plan settings except I reset display and drive to never sleep and will restart again.

By Gosh that reset power plan, then set everything to never same as before, took care of it. At least on 1 restart. I will make a note of this. Booted to full brightness.
Thanks for the ideas and the help !! Much appreciated.