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user_6de2db

1 Rookie

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1 Message

55

January 12th, 2026 14:17

Function keys for Brightness control (F11, F12) do not work as expected

I purchased Dell Inspiron 15-3552 (with Windows 10) just two months ago Everything was working fine. However, recently I started to notice an annoying thing with the function keys F11 and F12 for reducing and increasing the brightness respectively.

Without using the Fn key (next to Windows key), if I hit F11 it was reducing the brightness and F12 was increasing the brightness earlier - as expected. Now, sometimes, the laptop monitor goes to sleep mode the moment I hit F11 or F12. I have to press the power button again to wake it up. This behavior is very off and on and not consistent.

Did any settings get changed? How to fix this? Please help.

FYI - I have not changed the BIOS settings from default which could be multimedia. I can say this because other multimedia keys in the same row behave normally (even when this strange behavior is noticed in F11 and F12).

Thanks,

Bhagat singh poswal

Kflash08

3 Apprentice

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678 Posts

January 13th, 2026 16:58

I would avoid adjusting the brightness when the computer is about to go to sleep. If this is a reoccurring issue where you have to constantly adjust the brightness, consider disabling sleep, or extend the duration to something much longer. It sounds like Windows is putting the computer to sleep after 10 minutes or sooner, which in my opinion is way to short assuming that you're not using the computer on batteries. You can move the mouse occasionally to reset the sleep duration, or tab the CTRL key. Windows is most likely not acknowledging the F11 & F12 hotkeys, as that's being handled by the computer's firmware and not by the OS.

user_4df2c0

1 Rookie

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1 Message

January 14th, 2026 13:37

@Kflash08​

I am saying that f11 or f12 key
 is not working and not
 increasing or decreasing 
through the key,
 I have also checked this,
 the button is absolutely correct,
 if f11 is pressed along 
with fn in chrome then chrome goes to full screen, 
please help

Kflash08

3 Apprentice

 • 

678 Posts

January 14th, 2026 17:36

@user_4df2c0​ Do the brightness hotkeys work outside of Windows, like when in the BIOS or within the Dell recovery or diagnostics environment? If not, it sounds like a possible bug in the computer's BIOS.

If your Inspiron has a lock icon on the ESC key, pressing Fn + ESC will toggle the hotkey behavior, requiring you to always hold down the Fn key in order to use a hotkey function. You can try toggling it on and off to see if that fixes anything.

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