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mazstar1980

macrumors member
Original poster
Feb 4, 2010
31
0
Just switched my new iMac and it has the dreaded dog whistle, not as pronounced as my previous 3 replacements which were last generation.

I was hoping the new rev would have ironed the atrocious quality control.

I still have yellow discoloration but I can't be bothered. My lady needs a computer and she doesn't want PC. I'll give it a few more days and if I can tolerate the whistle I'll hang on to this one.

At least there is no dead pixels.
 

Btom

macrumors 6502a
Nov 19, 2009
571
0
Just switched my new iMac and it has the dreaded dog whistle, not as pronounced as my previous 3 replacements which were last generation.

I was hoping the new rev would have ironed the atrocious quality control.

I still have yellow discoloration but I can't be bothered. My lady needs a computer and she doesn't want PC. I'll give it a few more days and if I can tolerate the whistle I'll hang on to this one.

At least there is no dead pixels.

Could we get more details? Is it really the refreshed model? 21.5" or 27"? Is the whistling changing with the brightness adjusted? Could you post a screen picture?

Tom B.
 

IndustrialSpace

macrumors 6502a
Dec 31, 2009
696
1
somewhere
It doesn't surprise me that the new iMacs STILL have a yellow tint.

It's a design issue, not a defect. It will be with this generation until they redesign the iMac again. Just my opinion.
 

Btom

macrumors 6502a
Nov 19, 2009
571
0
It doesn't surprise me that the new iMacs STILL have a yellow tint.

It's a design issue, not a defect. It will be with this generation until they redesign the iMac again. Just my opinion.

There was just one new 27" screen picture I had a chance to took at (the yellow tint thread) and this one was very good (not "perfect" mind you, but ~90% of the surface was very uniformly grey), so maybe they did improve something in the design/process. But it is really too early to tell.

Tom B.
 

dwarnecke11

macrumors 6502
Nov 29, 2009
354
0
I've watched this issue closely since I experienced it with my i5 Week 45 model, which I returned. It seems Apple switched panels in March when they slowed (or halted) production and since then the issue has been much less severe.

As long as the yellow doesn't "jump out" at me I'm okay with it. It seems newer iMacs have greatly improved uniformity. A perfectly uniform screen doesn't exist at any price level.

I'm more concerned about the "dog whistle" backlight noise. Is this problem confined to 21.5" iMacs or 27" also?
 

derbystar16

macrumors newbie
Jun 6, 2007
12
0
Whistle

Mazstar... I'm sorry to hear that. I bought a new iMac when they were refreshed in October 09' and it had the dreaded dog whistle when adjusting the LED backlight. I went through 5 of them until I got one that wasn't audible.

I would have thought that they fixed that already.
 

mazstar1980

macrumors member
Original poster
Feb 4, 2010
31
0
I'm not concerned about the yellow screen tbh...it's definitely warmer on the bottom half and towards the right hand side of the screen.

What is most annoying is the dog whistle, that I cant live with!
 

alexxk

macrumors 6502
Jul 29, 2010
425
118
Is your the 21.5 or the 27....

I'm waiting all year long for this refresh to finally get an iMac and I'm already reading people having the same issues they had last year...

Now what??
 

eddvedd

macrumors regular
Apr 28, 2010
132
0
Just switched my new iMac and it has the dreaded dog whistle, not as pronounced as my previous 3 replacements which were last generation.

I was hoping the new rev would have ironed the atrocious quality control.

I still have yellow discoloration but I can't be bothered. My lady needs a computer and she doesn't want PC. I'll give it a few more days and if I can tolerate the whistle I'll hang on to this one.

At least there is no dead pixels.

Sorry to hear this, just got my i7 and it has the same whistle. On a brighter note, the screen looks great (no yellow noticeable to me anyway), and it's incredibly quite (except for the dog whistle of course). Mine's going back to apple, but I have a little more hope this time that my return might be ok because the whistle really seems to be the only thing keeping this one from being perfect.
 

mazstar1980

macrumors member
Original poster
Feb 4, 2010
31
0
Forgot to mention mine is 21.5 base model no customisations.

Apple knew about this in the previous rev I can't believe they didn't bother to fix the design.

I'm keen to see if the replacements have same probs.
 

powerbook911

macrumors 68040
Mar 15, 2005
3,999
379
When mine arrives, what can I do to test for the dog whistle? Is there a certain action that brings it out, or is it all the time?
 

ceshimm

macrumors member
Jul 10, 2010
74
0
When mine arrives, what can I do to test for the dog whistle? Is there a certain action that brings it out, or is it all the time?

same question. how to test out if the screen is normal and do not have any kind of issues mentioned above? going to buy one very soon.
 

mazstar1980

macrumors member
Original poster
Feb 4, 2010
31
0
When mine arrives, what can I do to test for the dog whistle? Is there a certain action that brings it out, or is it all the time?

There are a few steps I would take to check.

1. Are you in a relatively quiet room? You might have a hard time hearing it if you have music or tv on.

2. Listen out for a high pitched noise coming from the top left hand corner (left if facing screen). If it's there and your ears pick those frequencies, you'll know it.

3. Turn screen brightness to 0 and to maximum, try close your eyes and listen through the levels. Often it will be off at 0 and sometimes max brightness. This may sound weird but where your ears are tilted to can sometimes affect, try and tilt your head toward the screen corner.

4. If it doesn't bother you then thats great but it bother me and lots of people.or you mitt not have it which is great.
 

crillz

macrumors newbie
Jun 22, 2010
3
0
The amount of LCD issues in this refresh is way down. way way down. The yellow tinge is still there on some, but I'd say we are talking 15% of the LCDs and not 60-70% like the previous models. Also, in the last model somewhere around 80% had that dark horizontal line running across the screen about an inch from the bottom, this has been cut way way down, it's rare at this point.
 

mazstar1980

macrumors member
Original poster
Feb 4, 2010
31
0
crillz said:
The amount of LCD issues in this refresh is way down. way way down. The yellow tinge is still there on some, but I'd say we are talking 15% of the LCDs and not 60-70% like the previous models. Also, in the last model somewhere around 80% had that dark horizontal line running across the screen about an inch from the bottom, this has been cut way way down, it's rare at this point.

They have been out for 3 days, how did you come to this numbers?
 

IndustrialSpace

macrumors 6502a
Dec 31, 2009
696
1
somewhere
The amount of LCD issues in this refresh is way down. way way down. The yellow tinge is still there on some, but I'd say we are talking 15% of the LCDs and not 60-70% like the previous models. Also, in the last model somewhere around 80% had that dark horizontal line running across the screen about an inch from the bottom, this has been cut way way down, it's rare at this point.


I too have to ask... how are you able to make such an assessment? Do you work for Apple's Return dept. or engineering dept?
 
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