HELP 27" i7 backlight test

ttopp

macrumors regular
Original poster
Mar 1, 2007
237
0
Hi i got my 3rd 27" iMac and i have another one with back light issues please try this and tell me if you's get the same.

my problem is that with a black screen i get uneven black across it. when sitting in front its the bottom corners but if i look up from below the screen it moves about with me. its light coming through so on a black screen its not all black like it should be but a sort of a silvery glow in.

can people set there desk top to a black screen and let me know if they get it too or is it just that I have been unlucky and had two now :(
 

IndustrialSpace

macrumors 6502a
Dec 31, 2009
696
1
somewhere
That looks pretty bad. No black screen at all in the corners. You wouldn't be able to watch a movie at all on a screen like that.

What week is it from?

Is this a widespread problem like the yellowing?
 

ttopp

macrumors regular
Original poster
Mar 1, 2007
237
0
i have two here just now one a week 07 is as bad but its back in the box, the one in the pic is week 53.

:( no happy. apart fi the rank screen the comp screams, its really good but the picture is rubbish :(
 

mdewberry

macrumors regular
Aug 20, 2003
139
2
My fourth iMac (received in January) had the same backlighting issue as in the example photo.. Could really see it when I had the cool planet earth with black background wallpaper on the screen...
 

ttopp

macrumors regular
Original poster
Mar 1, 2007
237
0
post some pics o the good or the bad yins lets check the black issue...
 

stu212

macrumors member
Jan 23, 2009
94
0
I have had 4 iMac 27" all of them had the same backlight problems 2 of them had other problems that i returned them for and the third because of this backlight problem. I am just trying to make travel arrangements to return my fourth one.
 

ttopp

macrumors regular
Original poster
Mar 1, 2007
237
0
Its like the first black MacBooks, you got terrible contrast if the screen wasn't at a precise angle. but with this big screen you canny get it all at the same angle so its distorted the blacks??? I hooked my plasma up its not got as good a resolution (1080i) but the blacks are uniform and this tv is 5 years old....
 

slicecom

macrumors 68020
Aug 29, 2003
2,058
90
Toronto, Canada
Its like the first black MacBooks, you got terrible contrast if the screen wasn't at a precise angle. but with this big screen you canny get it all at the same angle so its distorted the blacks??? I hooked my plasma up its not got as good a resolution (1080i) but the blacks are uniform and this tv is 5 years old....
Plasma's don't have a backlight at all so thats not really a fair comparison, but yeah, the backlight bleed is annoying, and unfortunately it's common on the new iMacs.
 

ttopp

macrumors regular
Original poster
Mar 1, 2007
237
0
well they canny fix it at the repair shop. i had the last one in and the changed the screen and problem still there, changed the backlight board and then replaced a cable, no joy with any o those so it was to go back but i could hold on to the duffer till the replacement came.

that happened on monday but couldnt test it then as i was away on a trip lucky it came early or id have missed it. tested yesterday and bad backlight issues.

no happy emailed the customer service woman who was dealing with my case early yesterday still no heard back fi her yet :(
 

Attachments

slicecom

macrumors 68020
Aug 29, 2003
2,058
90
Toronto, Canada
here are pics of the yellowing :( and another backlight one
That's not a bad backlight, that's just how they look when you go off centre thanks to Apple not including a screen polarizer.

As for the yellowing, its definately there, but its not nearly as bad as some. I'm on my 6th iMac and that is less yellowing than 5 of them exhibited. There are perfect ones out there, but they're extremely rare.
 

ttopp

macrumors regular
Original poster
Mar 1, 2007
237
0
That's not a bad backlight, that's just how they look when you go off centre thanks to Apple not including a screen polarizer.
no thats bad backlight. non uniform blacks.. also from face on you notice it in the bottom corners. my macbook pro 15" is better at displaying black and it doesnt have IPS..
 

slicecom

macrumors 68020
Aug 29, 2003
2,058
90
Toronto, Canada
no thats bad backlight. non uniform blacks.. also from face on you notice it in the bottom corners. my macbook pro 15" is better at displaying black and it doesnt have IPS..
Then every iMac has a bad backlight. Take a picture of any 27" iMac displaying a black screen in the dark and it will look just like yours.
 

TMRaven

macrumors 68020
Nov 5, 2009
2,099
1
That's not a bad backlight, that's just how they look when you go off centre thanks to Apple not including a screen polarizer.
I get this too, and it's pretty annoying-- it's like I might as well be looking at a gray screen if I ever happen to look at a pure black screen from a great angle.


As for a backlight bleed, I guess I have some, but at the same time I guess it's what the average LCD panel gets with a super ****ing bright led lighting it from the rear. Most of the offblack in this picture is coming from flaring of the menubar and icons. However when I look at it with my own eyes, I see some gradients of backlight bleed on all 4 corners-- nothing I can't live with though.

http://i26.photobucket.com/albums/c104/twisted_metal_2/P1050079.jpg