In the past two years I bought a 42″ Samsung LCD television and a 24″ HP computer monitor and experienced the same level of noise which originated from the same source in both of them. The noise was a buzzing sound coming from the LCD display that was audible and nerve-racking.
One usually thinks about a faulty monitor immediately but after researching the topic for a few hours I came up with a better solution that eliminated that background noise completely. The noise is directly related to the brightness setting of the LCD monitor. Reducing the brightness of the monitor will start the buzzing sound while a brightness level of 100 will stop it.
I’m not a technician but I suspect that the noise is coming from the power supplies that power the small fluorescent tubes that are responsible for the backlight. Setting the brightness level to 100 eliminated the noise completely on both LCD displays. It was called Back Light and not brightness in the LCD television’s options.
Setting the brightness to 100 resulted in a very bright computer monitor display which I was able to turn down by using the brightness settings of the video card. The LCD television provided two independent settings for brightness and backlight to adjust the display.

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hehe ain’t that neat :D I put the brightness to zero and it did make a buzzing sound!
Awesome Post!!
thanks for the info :)
I read somewhere once that florescent fixtures don’t like dimmer switches, which sort of sounds like your problem.
yeah hate that sound to. Not when the pc is on but when everything is turned off (also the lcd) but when the wires are still connected.
I have my pc on my bedroom so when I go to sleep the buzzing noice just go on while the screen is turned off and that really irritate me. And unplugging the wire is also such a stupid thing.
Here is what I did, I disconnected sound cable and no matter what brightness it didn’t change.
Dark Kosmos my computer monitor does not even have a sound cable connected. But good to know that it is working for you and definitely worth a try.
I just bought a new Samsung 2433bw. Thank you Martin for the tip to increase the brightness to 100. It worked for me. I have a noise even at 99 but the monitor is silent at brightness 100.
I was ready to return my new HP w2338h monitor because I could not stand the noise….at a brightness level of 100 it’s gone. Thanks for the tip.
I’m so glad I found your post. I was ready to return my HP w2338h too. Brightness at 100 fixed it!
Thanks for this tip – have a 22inch AOC lcd and that damn noise has been driving me crazy so glad to find a work around. Doesn’t make sound all the time and sometimes I can ignore it but it really gets distracting when trying to get immersed in a good PC game
THANKS FOR THE POST, MARTIN. I had the same problems as some others regarding hp w2338h, and your post solved the problem. You are great!
THANKS! I was about to return a new Samsung 2433bw until I found this post. I find the monitor too bright at 100, but the noise level anywhere else is unacceptable.
Thank you so much! I just got a new HPw2338h monitor and I couldn’t find any fixes for that horrible buzz until I came across this.