07-08-2009 09:03 AM
11-07-2009 04:46 PM
12-07-2009 06:47 PM
Thanks for the brightness hint; it fixed my irritating humming noise too, but I wonder if it's just delaying a flaw that will create another problem later once the monitor is out of warranty!!
12-11-2009 12:31 AM
Another thanks for the tip here!
I've had my HP 2159m monitor for a few months and have only noticed the noise tonight. Granted it's extremely quiet in here which is rare, so perhaps the noise has always been there and I just never noticed it before.
I found that the noise disappeared when I tweaked brightness to about 75 - 79 %. Since I don't like the brightness that high with the light in here, I went back into NVIDIA Control Panel (right-click desktop menu) and re-tweaked the brightness/gamma settings there to help compensate.
12-28-2009 12:36 PM
I have an HP2159m and recently noticed the same thing. I tried all the suggestions in the forum but none worked. But, because I was in the menu of my monitor I decided to play around with some settings to see if anything else would make the noise go away. I discovered that the volume on my monitor was turned all the way up and was causing the noise...duh. I don't usually adjust my volume via the monitor but use the volume adjustment keys on my keyboard so I did not even think to check those.
04-05-2010 09:28 AM - edited 04-05-2010 09:59 AM
I have a 2159m manufactured in April 2009 and hear this sound as well. I'm pretty sure it's due to the design of the backlight power supply. When dimming the backlight, it pulses it on and off quickly, rather than truely changing its brightness. It's the same principle as most home air conditioners/heaters work, where they turn it completely on and off periodically, rather than running it all the time and varying the amount of cooling/heating (which is difficult to do). To vary the brightness, the time it's on during each pulse is varied, as compared to the time it's off (pulse width modulation, PWM).
Oh, wow, the speaker volume really does affect the level of this buzz. When I turned the volume to 100%, it was noticeably louder. Oddly, selecting HDMI Audio as the input made it even worse. So be sure to turn the volume all the way down.
I wouldn't recommend running at high brightness, because it will shorten the life of the backlights. I consider myself very sensitive to noise and yet haven't been bothered by my 2159m even when it's quiet and I can faintly hear the buzz (and I run at 0 brightness all the time). I wonder whether some of the sound others hear is being reflected off the wall; some cloth or other sound-absorbing material on the wall might help, though I'm just guessing here.
I agree that it's unfortunate that LCD backlight power supply designs haven't improved.