Q: New iMac 27inch screen flickering/tearing/shutoff

Thanks for the comment on sleep. The reason behind my comment is that the 24" 2.8 iMac goes to sleep very quickly and it is also running 10.6.2. I have browsed some Console logs but spotted nothing so far. I am not losing any sleep over it.

Like I said I have no idea if safe sleep is also on the desktops. I will lean no they don't due to your old 24" iMac went to sleep immediately.

Hi All,

I have a quad-core 27" iMac; got it on Friday. Don't see any blackouts however I do see the screen 'blinking' randomly. By blinking I mean it just seems to refresh very quickly. I would say it happens every 15-20 minutes or so. I'm afraid this means more serious troubles down the road... Like the blackouts and static lines. Also the lower half of the screen has a yellowish cast to it as some people have reported, not pretty at all. I am not sure how the latter could be fixed by a firmware update... But has someone had the same 'blinking' issues with their iMac?

Thanks!

Hey-

There is a separate (answered) thread about people seeing their screen flicker when the display is dimmed way down.

http://discussions.apple.com/thread.jspa?threadID=2249911&tstart=0

Apparently the flicker/dim behavior was resolved when the iMac was replaced. I am wondering if the readers here could perform the same test on their systems? The theory being that systems that flicker when dimmed are "bad" and will suffer the tearing/filckering issue. Devices that are good, will not flicker when dimmed. Obviously we would want to test this on known "good", known "bad" and "suspect" systems. Seeing this on known good systems would shoot the theory down. For our purposes, "good" means 27 inch screen that has not exhibited the tearing/flickering/black problems in 2 weeks or more of moderate use.

Worth a shot? Or is the collective wisdom that these are separate issues?

Hi, i'm posting from France, and first sorry for my bad English !
I have exactly the same problem. I had my Imac core i7 since 24th november, and the default appears to me 3 times. At the last time it appears 38 min after the computer starts. CPU was cold (34 °C) etc...
I try to disable wifi, bluetooth, change screen resolution, but it still....
I'm waiting for my new Imac which will be shipped, on 15th december. I'm not sure that the new one will be good....
I wrote in a French forums, and we are 25 persons having the same problem ! !
I bought this computer and one one my friend bought it too the same day, and he's having the same problem ! !

Please send us the first 5 digits of your serial number (maybe your friends too). We are trying to find when Apple will fix the problem.

quesmada,

You might want to read thru the last couple pages for a discussion between Phillip Anthony and myself. Like you I am a long time PC user that decided to make the move to Mac based on recommendations from friends and my experience with an iPhone (plus repeated problems with my Windows machines). I understand the frustration and voiced some of those same concerns.

As Phillip rightfully pointed out, these recent iMac problems are not the norm at Apple and as I suspect, are related to a third party vendor (i.e. ATI/AMD). My guess is they will get it sorted out sooner rather than later.

Perhaps you haven't had the problems I have suffered through ever since using Windows 3.0 but MS has had numerous shots in getting their OS right and haven't succeeded completely yet. If you have gotten them to admit fault, then you are luckier than I. Ha, even their Windows 7 ad campaign is subliminally suggesting that if anything goes wrong, then it is the user's fault..."Because Windows 7 was (their) idea!"

The choice is ultimately yours, but I personally know more happy Mac users than friends without Windows/PC problems. I haven't given up on a future transition.

Here are my 5 digits : W8945
It was build in week 45 and for my friend too (we ordered it on October 20th)

I had a flickering i7 (I posted 3-4 weeks ago in this thread) that was order back in the first 30 minutes of available on apple.com so it likely was one of the very first build weeks (I never wrote down the serial #). I returned it after only 48 hours due to heavy flickering and blackouts after less than 2 hours being on with minimal processor usage etc. PRAM resets fixed the issue but only for less than 2 hours at a time. Well I got the replacement only 10 days after shipping the computer back and I have now had the replacement for 10 days.

PERFECT under heavy usage.

Let's be clear for those on the fence. This may be an issue that a firmware or software patch will fix in the future but it IS a hardware issue through and through. They don't "all" flicker. Send yours back and get one that works, don't wait and hope for a fix that may or may never come.

Received my 27" iMac 2.8 GHz Intel Core i7 (Serial W8948...) yesterday, ordered Online Apple Store 27-Nov-2009, shipped Shanghai 01-Dec-2009, arrived 07-Dec-2009. About 10 to 15 minutes after startup the screen began to flicker during Software Update and progressed to 1-2 second screen blackouts.

I have logged a Case Number with Apple and they are happy to send a replacement as long as I send it back within 14 days or receiving it. I have informed them that I would like to hold onto it for a few days to analyse the problem before sending it back for a replacement (given that it is already here and the lead time for a replacement could be a while).

Are there any confirmed causes of this issue yet?
Are there any fixes other than resetting PRAM, resetting SMC, or changing screen resolution?

The obvious solution is to get a replacement, which I will most likely do, but I would like to understand the issue a bit better before doing so. All tests have passed in Apple Hardware Test and TechTool Deluxe. I have also posted my details on http://imac.squeaked.com

The flickering just started again after loading a webpage with Flashplayer on it, and the CPU Usage in Activity Monitor indicated Flash Player as having 300% or more.

Message was edited by: Glenn Farrell

My new IMac 27"/4850-512 blew its "logic board" after six days. The display went completely black....kaput! Fortunately, I didn't experience the flickering problem. On the contrary, the new display was simply superb. I take raw photos and use Entourage and the new IMac appeared to be perfect for my needs. It handles 30MB raw photos with ease with just a slight delay in displaying the image with the 8 GB 1066MHz DDR3 SDRAM and the 2.8 GHz Quad Core i7 processor. I shipped the new IMac back to the Apple graveyard in Jonestown PA. I hope they erase my photos from the HD! I was advised by Apple that a new IMac will be shipped from Shanghai on Dec. 16th and is expected to be delivered to me on Dec. 21st. which is exactly one month after the defective IMac arrived. The timeline: I used the new IMac for six days, it died and I took it to an Apple store on Day 7, I shipped it back to Apple on Day 11 after the shipping labels were emailed to me. I'm happy I have a one year old Mac Book Pro and a five year old IMac G5 still operating. (I almost gave the G5 away!)

skypeable wrote:
Hey-

There is a separate (answered) thread about people seeing their screen flicker when the display is dimmed way down.

http://discussions.apple.com/thread.jspa?threadID=2249911&tstart=0

Apparently the flicker/dim behavior was resolved when the iMac was replaced. I am wondering if the readers here could perform the same test on their systems? The theory being that systems that flicker when dimmed are "bad" and will suffer the tearing/filckering issue. Devices that are good, will not flicker when dimmed. Obviously we would want to test this on known "good", known "bad" and "suspect" systems. Seeing this on known good systems would shoot the theory down. For our purposes, "good" means 27 inch screen that has not exhibited the tearing/flickering/black problems in 2 weeks or more of moderate use.

Worth a shot? Or is the collective wisdom that these are separate issues?

My iMac doesn't flicker when dimmed, but I have only seen the flickering issue twice in 10 days, each time after a cold start (not sure if it is related) and the flickering was solved with a reboot.

My later thought relates to RAM which "might" explain the difference between old and new. The 24" has 4 GB RAM and I have 8 GB RAM in the i7. I have seen the word hibernation somewhere in a log when I went looking in Console.

No sign of flickering on this good i7, when dimmed. I am normally running on about 50% but I have tried it all the way down.

I still have no fix with my Apple LED Diplay + iMac flicker. After attempting to call my AppleCare rep at the number and extension he gave me 4 times last week (and emailing him a few times) with no response. I called the main number and spoke to someone new, who said engineering was blaming the problem on the EyeTV software causing my machine to wake from sleep randomly. Before the call I had already completely re-installed everything on my iMac and removed EyeTV and the 24" display still flickers.

So now my issue gets bounced back to engineering, I can't wait to see what they come up with next. My experience with AppleCare this time around is getting frustrating. I don't want to, but I feel like asking for something from them for all the time I've spent trying all of the crazy things they've suggested - returning my iMac, re-installing OS X, trying different power outlets, getting a new power strip and then my rep going MIA and not returning any of my calls or emails.