21.5'' iMac - Screen Noise

Any news for iMac 21.5" Display issues? Not only the 27" model is affected.

Finally, I get a new replacement iMac 21.5 and the annoying screen noise is gone.

BUT - I have 2 dead pixels and still there is a yellow discolouration at the bottom of the screen.

This is so annoying - I'll wait and see what Applecare says - at least they have been helpful so far.

Hello all !

instead of creating a new thread:

Are there folks outside who can confirm that Apple did eliminate the reason for the screen emitting this high-pitch noise in the latest batches of the 21.5 inch iMac?

Probably people with replacement iMacs, who returned their iMac because of the noise would be best to answer.

Thanks and regards

Hi! Issue is NOT cleared. Had my iMac 21.5" "fixed" last week. Screen & LED board were changed. Still makes the noise, screen is a little better than before, but still yellow tinge. Had Apple Care open another case# and call me when they are ready. My first & last Mac, I guess.

SuLlfons, Sorry to hear. That's Bad! You might as well have just swapped it out & taken a chance at the iMac Lottery. I would Keep it & wait until there is definite & complete fix. That's Bad news at this stage of the game.

Hi to all !

is there any news out regarding this topic? The 21,5 display silent at last? I am still looking for a new computer. Does apple want me to buy a new Sony vaio Laptop? 🙂 The only alternative ( the refreshed MacBook Pro series ) is also not in sight at the moment.

Thank you

Unfortunately no, my latest 21.5 iMac which was built 02 of this year still whistles/buzzes after the brightness is reduced from full brightness. I can't use the system for an extended period of time. I'm still working with Applecare to resolve this issue. It's too bad because the system is perfect in every other way.

Well, here in Japan, I've sent my iMac 21.5 for repairs. And they said they have confirmed the noise, but claim that its not a defect... so they sent it back to me as is. I don't know what to say. This is disappointing.

You sent it to Apple or a Apple Authorized Service Center. Call Apple!!

I received my THIRD replacement iMac today.

Yellow screen - Check
High pitch noise - Check
Very mild flickering at 0 brightness - Check (is this normal?)

This is beyond a joke, any loyalty or good will I had for the Apple brand is all but gone. I used to actively promote Apple computers and encourage people to check them out but I'm forced to do the exact opposite now.

I feel like I'm being really fussy and pedantic but I just want my computer to work as it was designed to. My second iMac had NO high pitch noise - so I know it is a defect, one that is related to screen brightness as it disappears when full or zero level.

I'm on my forth 21.5 iMac. Just like the first three units it makes the same whistling/buzzing noise after the brightness is reduced three or four notches. It also has the yellow tinge issue on the right side of the screen. The first three units didn't have a noticeable issue with yellow tinge (As least for me). Finally this units power cord will not plug fully into the unit. Last time I was at the Apple store I notice all the 21.5 iMac's with the ATI video cards made some sort of whistling/buzzing noise, some worse then others. So to make a long story short I'm giving up on this model. My question is that has anyone noticed the whistling/buzzing noise on the 27' Quad Core iMac?

Hi,
the buzzing noise is not located on the graphics unit. It's a "feature" of the backlight LED's dimming circuit. Apple has chosen to really dim the LEDs instead of just adjusting the videos brightness. The advantage is that now the LEDs really use less power when dimmed, the disadvantage is that the circuit vibrates. You can hear a similar sound on any dimmer for your home lighting.
The trick is to adjust your desing in a way that does not buzz so loud the user realizes it. The design of the dimmer board leads to buzzing noise; manufacturing tolerances produce units that are barely audible or those that drive you nuts.
Problem is that you cannot know about longterm effects of the buzz to your hardware. It may fail early - noise means vibration, vibration could losen the soldering or simply wear things out in some way. It will certainly stand the 3 years of Apple care.....

That said, the 27" unit may have the same or a different dimmer circuit - but you never hear a complain about it from those owning a 27". But the yellow tinge thing seemed to be more prominent on the 27"ers.
Since the pace of updates to the "yellow tinge problem" thread I have subcribed to slowed down pretty much to 0 since end of January, the new displays seem to be OK from now on.
The dimming noise still persists, at least I have not heard of a fix, only of the occasional "good" machine one or the other received.

My 21" has been "fixed" once, comming back louder as before with a slightly less yellow screen. I will give it to a second repair next week. Money back is hardly an option for me - bought the machine in one shop, Apple Care in another neither of the two Apple directly.

There is a software called "shades" that will provide with a software workaround: The LEDs wil stay a full brightness, but the video card will lower the overall brightness of the picture displayed. That way, it will be silent but use maximum power. I am afraid, that's the kind of software fix Apple will bring as the official remedy one day....if at all.

For my part, I can hear my unit but it won't give me headaches (as the full brightness of the display gives me in the evening) - so I tolerate it for now.

I am hoping for the second repair to provide me with a good display at last -

If only the mac mini offered o 500GB harddrive in it's minimum spec, I would have gone for that one - but like it is today, Mac mini makes no sense if you want to have an Apple keyboard & mouse and also need a new display (Apple or not).

Message was edited by: SuAlfons

Get an Oct '09 iMac 24". MacConnection has a deep discounts on 3.06 24". That is what I did versus waiting for a fix that may not come.