New iMac 27inch screen flickering/tearing/shutoff

I think that since someone before said that this problem appears on his 24 inch ACD when connected to his new iMac, that prove it is an issue relating to the GPU. Now, to know if this is a driver or a hardware problem, those experiencing the problem need to try running Windows in boot camp for a while. If the problem is absent in windows, then we can be sure it is a mere driver issue. If it is still present, it would indicate that this could be a hardware or firmware problem (most likely, but not 100%). So now someone with the problem ought to try it!

Thanks. Just canceled my iMac order. I could have lived with a screen that is really a big mirror but if it also flickers that is a showstopper, sorry Apple.

Hi all,

I too have had this problem with a 10 day old iMac with 27 inch screen. I am returning to apple today (hopefully sans restock fee, as it's defective) and I will wait until they resolve this to buy. I love the computer, but I can't accept a defective unit. I noticed two things that I wonder if other people have seen:

1) This started only after i used the migration assistant (coincidence?) to move accounts from my laptop to the new iMac.

2) Turning up the brightness seems to make the problem go away.

Thanks,

-Joel.

Well, I'm both a little frustrated (that this is an issue) and relieved (that I'm not the only one experiencing it). Same issues and symptoms for me that have been reported by everyone else: occasional 'flickers' of static bars across the screen, sometimes the screen blacks out entirely for a half-second or so, and twice I've had the desktop 'shift/wrap' downwards, showing the menu bar about three inches below the top of the physical screen, with a 'bar code' effect immediately above the menu bar.

My machine is a custom order through the online Apple Store, upgraded to the 3.33GHz processor and the ATI Radeon HD 4850 graphics card. Since a number of the posts in here have been from people who purchased their machines through the physical Apple Stores, and will therefore have stock configurations, I'm thinking that this points away from the GPU, and back towards either hardware other than the processor and/or GPU or to software.

As has been the case with at least some other posters, I also used Migration Assistant to move my account over from my prior machine, in my case a Dual 2.0GHz G5 running OS X 10.5. Are there enough of these cases to start pointing towards a software issue caused by migrating (either through Migration Assistant or Time Machine) from a 10.5 system? I hope so -- I'd much rather have this be a software issue than a hardware issue.

I'll do the PRAM reset that two or three people have mentioned. Any word back from those who have tried as to whether that was a long-term fix or not?

To clarify, I also ordered a CTO from Apple online with the 3.33GHz but I have the Radeon HD 4670 graphics card.

I had the last couple of days off (Melbourne Cup!) but I am yet to see any more problems after the PRAM reset. I have been using VMWare Fusion 3 the whole time (since the main problems seemed to start after installing that) but not seen a single flicker, blackout, menu problem, nothing. The machine has been left on the entire time since the reset (a week ago).

Can anyone else who has done the PRAM reset comment if they have since had a re-occurence? I want to be sure that I just haven't put off the problem for a while and miss out on the DOA return within 14 days.

Just rang the Apple people (in Oz) because the iMac I bought on Friday last week started exhibiting the flickering and blackouts you guys have identified. Got the standard "unplug everything and turn it back on". I have been asked to call back as soon as it happens again.

I told the guy that it was a live issue on their support forum and wondered whether Apple had been attempting to identify the problem given the large number of complaints. He told me that he hadn't heard of the issue until I mentioned it. Doesn't bode well for any big picture solution.

Perhaps their just worried about having to conduct a major product recall. Should have thought about that before deciding to launch them early to trump the Windows 7 launch.

It has been about 24 hours since I did the PRAM thing. It seems to be better. I experienced one flicker earlier in day, but none since then. It is too early to say if this will be a permanent fix. I also mentioned to the Apple guys about the forum. I am sure they are trouble shooting this issue, but wont make any official statements until the issue has been completely worked up. I will be hesitant to ask for a replacement if they offer since this seems to be a pervasive manufacturing flaw. I will keep you posted if it stays fixed.

Mine has got gradually worse. Zapping the PRAM and rebuilding the Mac from the install DVD doesn't fix it.

Mine is going back for a replacement. If that's the same then I will be getting a refund until Apple acknowledge that it is a problem.

Here is a video of how bad mine has got:

http://www.youtube.com/watch?v=20v3vUfDrFE

It stays like this for about 20 minutes then gradually stops. NOT GOOD!

Same problem for me, what i did:
shutdown imac, unplugged it, eras all data, reinstall SL, rest PRAM, do hardware test. i didn't use migration that time.
For 1 day was fine , and now it's back again, flickering like this : http://www.youtube.com/watch?v=O8ugYKmSCFA every 2 or 3 minutes.

I get the same symptoms rebuilt the OS several times following a driver problem for my printer and thought the flickering had gone but it is back with the lines and black screens!

I called applecare after a week of owning the 27" screen and having these issues which seemed to only occur after coming out of sleep.

After talking with the lower level tech's, I got to a senior tech who helped me out. I sent him some screenshots from my video of the issue happening along with some video snippets of the issue. He was leaning towards it being a hardware issue. I then said I took a few Comman + Shift + 3 screenshots during the monitor hissy fit and these did not show any signs of the issue. After saying that, he immediately declared this a hardware issue and helped me with some choices to get it fixed or replaced.

An Apple store near me was willing to work with me on a complete exchange sans restocking fee. The tech setup an appointment for me, and the next day I had a new machine.

It actually feels different on this new one and I have not had any issues yet(fingers crossed). One of the issues I failed to mention earlier was that the computer would not come out of sleep without actually pressing the power button a few times, then moving the mouse. This new one wakes up with a spacebar touch, just like my previous iMac did.

I'd suggest anyone else with this issue point to the video I posted earlier (and others), and replace the system as soon as you can. Apple still does not have a solid answer on what the issue is, but hopefully they have some clues now after all of our posts and evidence.

I have the same issue but not as bad as seen in some of the videos here.

And it seems to me that the issue is only after turning the Mac on after a long "rest". Then I will see black flickering for some time. When I reboot, the issue doesn't appear.

Oh well, I have to bring it in to the Apple store anyway as it shipped with a nice crack in the glass of the monitor.

Message was edited by: Ben Koether

I've recently purchased my iMac about a week ago from the apple store, all was working fine and now the screen is flickering quite badly, rang apple care and performed the reset with the keys alt, cmd, p & r held down when starting up, this helped but this morning it is reverting to the flickering again. I've got a genius appointment on Friday and have the flickering recorded, but i'm worried will a replacement fix this current issue....?

I am perturbed by the amount of problems that I'm reading here about the new imacs. I was about to order a i7 but I guess I'll hold my horses. It seems that there isn't even an official acknowledgement of the issues from Apple. I suppose one should not anticipate a solution anytime soon.

I think it takes courage to be an early adopter for Apple products.

According to the description of the upcoming 10.6.2 patches, it'll fix a screen flickering issue:

"The latest build allegedly provides a number of GraphicsDrivers fixes, including resolutions for crashes with OpenCL, a screen flickering issue ..." (From: http://www.appleinsider.com/articles/09/10/16/appleseeds_new_mac_os_x_10_6_2_beta_todevelopers.html)

BUT, this message came out on 10/16, which is a few days before the announcement of the new iMacs. Unless the new ones are susceptible to flickering!

Anyway, the very latest details about 10.6.2 may be addressing the Flash problem that a lot of people are (sometimes) resolving by messing with the wireless setting of the new iMacs:

http://www.appleinsider.com/articles/09/11/04/appleslatest_10_6_2_beta_packs_fixes_for_vmware_imacs_appletv.html

Let's see how things go after the patch is out and people start installing it. Hopefully the flickering and performance issues will be fixed by this.

Eager to order an i7 but it's best to wait until people start receiving the i7 Quad cores and observe this place for a few weeks ...