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New iMac 27inch screen flickering/tearing/shutoff

I have been experiencing some problems with the all new iMac 27inch display.
At non-fixed intervals i will get one of the following:

Screen distortion/flicker somewhere random in the screen (feels like it is more in the lower part) that looks like a horizontal bar of about 2-3inches just popping in and out of the screen.

Screen will go completely black for a second and then come back on. Sometimes 2-3 times in a row.

Somebody else already made some video-clips about these problems, I am experiencing exactly the same behaviour.

http://www.youtube.com/watch?v=SjOxlxVz5Os
http://gallery.me.com/larzy#100025

Just to not that in the course of writing this post my screen has flickered 13 times and has gone black 2 times.

iMac 27inch 3Ghz 4GB 1TB ATI 4670, Mac OS X (10.6.1)

Posted on Oct 27, 2009 3:56 AM

4,486 replies

Nov 9, 2009 4:27 AM in response to Jan Sampermans

I’ve sent back my first iMac 27’’ because of a crack in the glass. The glass of my second 27’’ is ok but it has this flickering failure. So I did the Command + Option + P + R reset and the flickering vanished. Unfortunately it came back after 24 hours.
Shall I really send back my second machine to try the third one?

cataldoc

Level 1

0 points

Nov 9, 2009 9:49 AM in response to mactoubib

I can confirm that the issue is software (at least on mine).

I followed what mactoubib suggested in this topic (replacing ATI drivers) and now I have no more flickering.

Nov 9, 2009 10:30 AM in response to Jan Sampermans

I was at the Munich Apple Store today where they have four 27" iMacs. All C2D. I tested them all for about 10 minutes each and they all ran without any problems. No flickering. No interrupted flash movies. Playing flash movies on youtube.com never had more than 50% processor usage. I'm still waiting for the i5. Hopefully mine won't have any problems either. My first MacBook (white) had flickering problems too and needed two replacements of the logic board. After that I didn't hae any more problems.

mknez

Level 1

4 points

Nov 9, 2009 11:08 AM in response to Jan Sampermans

bought mine on november 3th 2009 in Slovenia. same problems as you have. already return it and waiting for the money. will buy another one as soon as apple resolves the problem. there is no point in purchasing another one with the same failure. must say i'm very dissapointed.

you can see the failure in the picture....here:
http://fensismensi.wordpress.com/files/2009/11/ererr.jpg

kawo

Level 1

4 points

Nov 9, 2009 12:58 PM in response to mactoubib

I also had the flickering problem on my new 27" iMac. I can also confirm that the solution from mactoubib fixes this. After replacing the ATI graphics drivers the flickering is definitely gone on my machine.

Last week I've installed Windows 7 via Bootcamp, spent quite a while there, and never saw any flickering. From then on I was quite sure it could only be a driver issue and I was no longer tempted to return or exchange my iMac.

Nov 9, 2009 2:18 PM in response to Jan Sampermans

It's about time to install the 10.6.2 update. I can confirm the new ATI drivers are included that fixes the flickering problem. Enjoy

Dick T

Level 1

5 points

Nov 9, 2009 3:00 PM in response to mactoubib

How can you confirm the new ATI drivers are included in 10.6.2? I just installed 10.6.2 and checked the ATI drivers and they are the same version 1.6.6 dated 9/10/09 that were there before the update.

And I don't know yet about the screen flickering/blacking out as I just did a restart before doing the update and everything has been ok. You know, it seems to me that a driver issue is unlikely only because my iMac has been flicker free since I bought it 11/2. Why would a driver issue suddenly appear 7 days later? Doesn't make sense to me and I'm no newbie with computers.

Nov 9, 2009 3:32 PM in response to Jan Sampermans

I just installed the 10.6.2 update and everything was ok for about an hour. But now the screen is flickering again.

Nov 9, 2009 4:20 PM in response to Dick T

Hi dicktwi,

For me the drivers are dated November 3, version 1.6.6.25

You can download them at the end of this message – and compare with yours, please let me know if any differences. Concerning relationship drivers/flickering, you can do this easy experience. Move all ATI drivers especially the ATI4X00. Restart your iMac and load the Arabesque screen saver. Your machine will flicker. This is why I said it's a driver problem. By the way it seems there are different versions of the ATI drivers. I saw versions listed from 1.6.4.7 to the latest with 10.6.2 update 1.6.6.25.

homepage.mac.com/mahers/ATI_NEW.zip

Nov 9, 2009 4:29 PM in response to mknez

My Mac got today the same Swine Flu symptoms. They are all infected ;))) iMacs need a proper doctor!!!!

Nov 9, 2009 6:08 PM in response to StileselitS

Hi
I got my Imac 27 1 week ago and the problems started 2 days ago. I had the white lines and some blackouts. Today I updated for 10.6.2 and I am testing it now. For the last 20mins it seems OK...let's wait then.
I checked the ATI drivers and they are dated 9/10/09 but are already 1.6.6.25, this is the last version, right?
If I have the problem again (hope nottt) I will let you know.
regards
f

Rick Lang

Level 4

1,237 points

Nov 9, 2009 7:06 PM in response to Jan Sampermans

Jan, I do not think you have posted any messages in your thread since your first message. It looks like the OS X 10.6.2 upgrade has resolved the problem perhaps with updated ATI drivers. Time to confirm on your system and mark this thread RESOLVED? It's a shame that people are so impatient that they've already either returned their purchased iMacs, cancel orders, or stay with their Windows PCs instead of switching to the Mac because of this problem.

Nov 9, 2009 7:28 PM in response to Rick Lang

Thank you Rick, I did'nt think to ask Jan to close that thread. According to me and time spent on this issue. I can write that thread is resolved, unless someone came back with another flickering problem even after installation of latest update 10.6.2.

MarkyJ

Level 1

0 points

Nov 9, 2009 10:53 PM in response to mactoubib

I am not sure if we are jumping the gun saying that the issue is resolved? My problem took a few days to appear, then a week to re-appear after the PRAM reset.

Having said that, I can confirm that my iMac had ATI drivers version 1.6.4 dated 10/9/09 4:36pm under 10.6.1 and now they have the same date/time but are reporting version 1.6.6.

No flickering yet, but it has only been a couple of hours. I have delayed the pickup of my iMac DOA return to see if the problem is fixed, but I am not convinced we can declare the problem solved just yet...

Nov 10, 2009 12:39 AM in response to MarkyJ

Hi guys, sorry it has been a bit quite after my first posts, but I have been following the thread closely.

Over the last few weeks I have only experienced these errors on my machine 3 times. Every time they were solved by a reboot. I think there are others in this thread that had it way worse then me.

I'm downloading the latest Mac OS X update now, so let's see...

New iMac 27inch screen flickering/tearing/shutoff