New iMac 27inch screen flickering/tearing/shutoff

From the original setup disks.

I had a brief search for any older MAC drivers but it might mean that due to the Imac 27 being a new machine and only now using these older 4xxx cards it only has the latest drivers, not sure where you might find them or if they are available.

Sorry guys this has only been my exprience with a PC but it seemed so similar.

As previously reported here, my 27" had this problem after day 2. Much worse than some of the videos posted. (Please see my previous reply for a video of mine. It was really bad).

I got a replacement on Monday and so far I have not had any problems. I have been leaving it on over night and waking it in the morning and it seems fine. FINGERS CROSSED!!!!! And good luck.

I will let you know if the flickering starts on the new one.

StileselitS : 20% faulty iMacs??? Is it possible that every 5th mac is with a fault?? Did apple test the 27" imacs?? That's a huge percent. I think that the real percentage must be lower because if not, there will be a huge lost for apple, and it is not an apple's habit. Maybe only the first ??hundreds, thousands?? were with a fault.

BTW: I order new 27" with i7 yesterday, so I hope that I will be an owner without a fault imac.

Ugh. No luck... after erasing everything and reinstalling with the updates, including the latest ATI files the flicker is back. I'm at a loss. I guess I'll be heading back to the apple store after all. FAIL.

You see I do not really know where this % come from. IT may be just pure observation from a store itself. 20% seems a lot for me as well. Anyway As I have mentioned before I did bring my one to store where I could see how work my replacement. IT is 3rd day and still nothing at all !!!!!!! Works beautifully! I keep fingers crossed to keep you updated. If more computers will be working like mine with no problems then for me it proves that it was hardware issue.
Enjoy your Imacs over weekend 😉

I don't mean to be negative, but realistic. My new 27 worked perfectly until day 8 and then... flickering...flashes...blackouts. Repeated 2 days later. It's now day 13 and still no reoccurence. Don't care a whole lot now because I'm waiting for my Core i7 to be shipped and I'll return this Core 2 Duo.

Hi

2 days after the update the problem returned...worse. I will call apple on monday.
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My 27" i7 quad core with the 4850 graphics came in yesterday. I'm running 10.6.2 (a migration from my previous 20" iMac).

After running a few hours I also began getting screen flickering and intermittent black screen. This would be followed by horizontal lines about 1" wide towards the lower half of the screen. I rebooted and all was fine until late this morning when I had a repeat of the entire event.

I wanted to add my hat into the ring. What to do.......

Bill

This just has to be a software/firmware/driver issue. Apple's going to have a nightmare on their hands (if for no other reason than the sheer number of returns they'll get) if it isn't.

On my three-day-old i7 machine, I've only noticed two things that might be considered "flickering," and both times they happened were after the exact same event...right before my machine was completing a shut-down prior to a restart. However, both of these events also occurred while I was running the machine post-Migration Assistant transfer, when I also noticed significant animation stuttering. After I did a clean install of the OS from DVD and installed all of my apps from scratch, I haven't seen any stuttering or flickering -- which certainly isn't to say that the latter couldn't still appear, based on what others have reported. But I'm positive that some kludgy drivers made their way over from my 10.5.8-based iMac during the migration as evidenced by the performace problems I noticed that I now no longer have.

Message was edited by: Schwa72

Sadly after 3 days it's happening to me too. 27", 2.8ghz i&, 8gb dd3, Ati Radeon. Used it all evening on Friday, all day Saturday and it was fine. This morning the flickering started after a half hour of use, then the screen now goes black every 30 seconds or so (4 times while writing this). Same behaviour , now bar has gone to the top of the screen

Forgot to include the video of flickering, blackout and bar going all the way up

http://gallery.me.com/gianlucamanzo/100191

Yeah... just got off the phone with tech support. Did a HD repair (because errors were found) and so far no issues. However, the tech said that it may in fact be the video card and that apple engineers are "aware of the issue and are working on it". They reportedly are "leaning toward it being a hardware issue" right now but are still trying to identify the exact problem. He said that if it was his computer he would probably just get a replacement computer if you are within the 14 day period because it seems to only be affecting a "relatively" small amount of new iMacs.

Thus, I just got off the phone with Apple and I'll be getting a replacement. Too bad I have to have it shipped AGAIN from China since I did some upgrades and ordered it online. This is really upsetting and even though I've been waiting since my order was placed on 10/20/09, I would rather have received a working computer and have received it a week or two later once everything was worked out... I'll report back with any issues in the replacement computer (after I get the thing sometime next year the way they are probably backed up right now).

I hate to have to include myself in this thread. I've had a new iMac 27" with Dual Core (1TB drive) for about 18 hours now. And I've been noticing the flickering/banding almost from about one hour after startup. It's not horrible, but it's persistent enough to make me very concerned. The occassional blackout of the screen, in particular.

I didn't upgrade the RAM or modify anything out of the box, short of transfer photos and music/apps from my old 20" iMac. I think the flickering seems to get better (less frequent) the warmer the machine gets. Which seems counterintuitive, I guess.

I'm going to watch it for a few days before I start worrying about repacking this and hauling it back to the Apple store. I did buy the extended AppleCare, fortunately.

guitarguy09,

If you haven't returned your defective iMac yet (I'm assuming you can return it to an Apple retail store) (I hope that's true), you might want to try what I did. I talked nice to the manager of my local Apple store about the widespread video problem, told him about my talk with tech support and that I wanted to order a different iMac with the 4850 card. He was very understanding when I told him that I had only 3 more days left in my return period and would be left with no computer until the new one came in ? weeks. He wrote on one of his business cards that I could keep my current 27 iMac and return it at any time after the 14 days without a restocking fee. He told me that he would appreciate it if I would return it asap when I receive the new one.
You may want to give that a try.

i am on day 3 of new 27 in imac base config and am also experiencing the same issues. i wonder if a firmware update won't fix this. i will probably just go make them exchange it instead.

when i was migrating all my data and programs last night i noticed the spinning wheel ALOT. it was very disconcerting. i got it when doing basic things, without a heavy workload.

i haven't noticed it today.