AW2521H, buzzing noise

Try using the monitor at 60 Hz, to see if the noise goes away. 

If it does, I would contact DELL tech support to see what your options are.

Interesting, it does only happen at 360 HZ. 

It's likely related to the PWM circuit used to control the LED bulb(s) in the monitor.

I might have spoken too soon, but the buzzing sound is still there at 60hz, just a bit less audible. This is the first alienware/dell monitor I've ever owned (I've owned several) that has this buzzing sound. Really weird.

It's the way the LED backlight bulb is being controlled. The system used to prevent flickering and other side effects is called PWM (Pulse With Modulation).

A few things to try to see if it makes a difference:

- Under Game mode, Set Variable Backlight to off.

- Set Dark Stabilizer to 0.

- Under Gsync Processor, try adjusting the Nvidia ULMB Pulse Width value. Try to increase rather than decrease.

Also, iIf that works, it appears you may be experiencing an issue with the connection for the RGB to the "Alienware" logo causing the noise. 

No, this shouldn't happen but seems to happen to some users.  It looks like it you're unlucky that this happened twice.  If this fixes the issue, but you want to keep the RGB effects, try changing up your color scheme. Or you could go try your luck at #3. 

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@ruleth wrote:

Hello, I purchased this monitor through Amazon and noticed that it's making a buzzing sound even when the monitor is powered off. The only way to make it stop is to unplug it. I returned the monitor thinking it was a defect and purchased another one and low and behold the same issue is occurring. I talked with tech support and asked them if it was a fan or something else that could be audible and they said no.

Is this a known issue? Did I hit the lottery and get 2 bad monitors in a row? I notice that the buzzing sound gets fainter (still annoying though) if I reduce the brightness.

Any help appreciated.

edit: They both have manufacture dates of April 2021.

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Actually, I'm not sure this has to do with the LED backlight bulb.  

Try pushing button 1 on the OSD to open up the menu, go to the third item, "AlienFX Lighting" and select "off."  I believe this should eliminate all the noise you're hearing.  

That was actually one of the first things I tried and unfortunately it didn't work. Any other suggestions?

Did anything I suggested make a difference?

Yes, I tried your suggestions as well, didn't make a difference. I think it's just the design of the monitor, not a deal breaker, just unusual. I wonder if all ULMB monitors have this issue.

I had the same issue on my X17 R2 laptop.  I heard a slight buzzing/static sound whenever I scrolled on a webpage.  I changed the Refresh rate from 360Hz to 60Hz.  That seemed to fix the issue.