I have two LG monitors (both 23MB35PM) which have an annoying and distracting feature of automatically changing their brightness at random times, probably due to some power saving mechanism.

How can I switch it off?

3 Answers 3


The option is not in the main menu, but has a dedicated button here:

enter image description here

Click the button enough times to select OFF.

  • 2
    On my monitor (23MP55) there was a "READER" button
    – fpg1503
    Aug 12, 2015 at 14:31
  • 5
    @fpg1503 "READER" doesn't help in my 23MP55. The button next to it, "FUNC", has the function to disable auto brightness :)
    – Andres F.
    Dec 6, 2016 at 4:12
  • 2
    READER solved it on my 24MP55. Thank you @fpg1503
    – Chud37
    Jun 29, 2017 at 10:37
  • For my LG 32UP83A-W it did not have any button or menu item to disable this. For me I disabled HDR from my macbook pro display settings and it is not auto adjusting brightness till now, will update the comment if i see the problem again.
    – viky.pat
    Feb 2 at 22:39

I have the LG 24m45 and I was having the same issue. I looked all over for the menu to change it, however it is actually in a special menu-which is an awful idea. I found the separate menu by pressing down the function(FUNC./) key twice and the menu popped up. Hop this fixes your problem!

  • +1 Also works on the LG 23MP55. Thanks!
    – Andres F.
    Dec 6, 2016 at 4:13
  • 1
    UI horrible on that model - have you seen the navigation in the menu? Surely designed by electronic engineers. Nice monitor, though!
    – Rolf
    Oct 2, 2017 at 11:07
  • 1
    Same for 24EB23. Press "Func/>" button to get into a separate menu where you can disable the "power saving" stuff. I have 2 displays of the same model, one was constantly changing brightness, the other was not. It was driving me nuts.
    – Brane
    May 13, 2020 at 21:40

In my LG monitor, which I purchased a few weeks before, this feature (automatically changing the brightness once every while) was annoying.

I found that I can disable this feature by setting the following option:

Menu -> Settings -> General -> Smart Energy saving = OFF

  • Wow. It took me forever to figure this out. I was blaming the GPU before. Works on LG 32gk850.
    – n1000
    Jul 31, 2021 at 21:17
  • The feature may also be called DFC.
    – mirh
    Jan 30, 2022 at 23:06

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