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

Hello Gille,

I just wanted to ask a quick question. I am also based in Belgium, and would like to order a 27 imac, either from apple online, or from a reseller in the centre of Brussels, ideally tomorrow(!). The reason I don't want to wait a while is a financial one (belgian tax year is ending)

My question is (and I wanted to email, or private message, but I don't see a way here) is did you order online from apple, or from a reseller, and furthermore, was it a problem for them to pick the defective unit(s) directly from you? I don't have a car, so can't go to the outskirts of Brussels with such a monster computer...

Many thanks in advance (sorry dat mijn nederlands nog niet goed genoeg is om het allemaal in nederlands te schrijven)

Ordered my i7 iMac dec 8. Got it dec 22.

Day 1 there was no flickering, and I thought I had a problem-free computer. On day 2 the flicker & blackouts started to happen. This is a week 50 machine.

Installed the firmware graphics update, and for 5 days there was no flicker/blackouts, and (again) I thought I had a problem-free computer.

Today, when the machine was on screensaver (the one with iTunes coverart), the first flicker appeared again, followed by some more and a couple of blackouts.

I am now going to phone Apple, insist on I get a new i7, do a transfer of settings and documents from the "old" machine to the new one, before I return it.

Rudy Norff wrote:
What you could try to do is also take a movie of the screen with the quicktime player and see if it shows up there. It might just be that you were a little late while taking the screen shot

OK so none of the flickers blackouts so up on the screen recording. Not sure what this means could be screen or power supply.

I have the flickering when running Windows 7 on Parallels Desktop 5, and also have it when in my regular Mac OS 10.6.2. Blackouts as well (which are really annoying). I called Apple for the second time, after applying the Firmware update which did not stop the problems. They told me to bring the machine in to an Apple Store or certified apple repair place and have them "look at it." They admitted this time that it is a known problem, and he told me sometimes it's a "loose cable" inside the machine (whatever that means). I'm not sure if I want to mess with this until it is clear that Apple has a fix, as I don't want to be without my only computer for a while. Anyone else heard this particular rumor?

hey Sigbox

Apple never made it difficult to listen to my problem. For the first one, they made me test the system. It's was all "ok" except the flickering off cours. So they've simple picked it up with tnt (tnt calls and makes and appointment). In the next 5 days they have send me a new one (with ups).

This time it had a massive yellow tint + a very noisy dvd-drive. So... i did the same thing and they've changed it again without any questions (and gave me a case number).

So.. to keep my bad english-story short ... 5 days later i got my 3rd mac and to this day (+- 1 month) i has been flawless.

I bought it from the apple online store. You best avoid Brussels because then you have another person in control of your "potential turnbacks".

So.. it's ok for me now and i'm very happy with it.
If you want to private mail about it: XXXXXXXXXXXXXXX

<edited by host>

greetz
gille

I only getting flickering when running Windows 7 under Parallels 5. At first I thought this was a Quicken 2010 problem but then this past weekend I got a flicker/blackout with Quicken not running.

Hi all, I need to chime in too, I have been watching this thread for about a month, haven't posted anything hoping that things would get straightened out, obviously they haven't. I have had 2 imac's now, a dual core 27" which flickered and tore and had the yellow streak along the bottom. The second is an i5, it flickered and tore when I first got it but hasn't done it till I started watching a youtube video, where it flickered again, I put it to sleep and then woke it and haven't had flicker since yesterday, but it is not fixed. Anyway, to those who believe this in not wide spread because the imac they have isn't doing it should be happy, but I personally have seen it on my 2 imacs and one at best buy (the yellow streak), so I have percentage wise, had 100% a failure rate.

My week 48 i7 iMac was delivered December 3rd. Despite crossed fingers and toes, I am now a victim of a display issue.

While reading an email last night, the display shut off, then came on again a second later. It was accompanied by a little click sound exactly like the one I hear when putting the iMac to sleep (as the display shuts off).

I guess it is time for a call to AppleCare...

Gille, just a quick thanks for your reply, much appreciated.

Let's deal with some facts...
1 - We know there is a problem (I have seen the You Tube video).
2 - We have all kinds of suggestions, rants, compliments, etc..
3 - It is not really temperature related; happens after cold starts or after using for a long time.
4 - Power supply related, of that I am not certain, but I doubt it.
5 - Cable or sensor related, not really, we replaced cables and sensors and it did not correct the issue.
6 - OS related, doubt it, as people had nicely reported that it happens under Mac OS, Windows OS and in Parallels.
7 - Display panel, or LCD, problem. Maybe. But of those reporting the problem and stating it has gone away, an LCD panel problem would not. It would get worse. Remote desktop-ing in does not constitute a valid test. Usually a separate display demonstrates no problem or the same problem. Given that these iMacs have separate video cards, the same rule as applies to laptops does not necessarily apply.
8 - The Intel i7 and i5 processors are new. I do not think we have seen it reported this occurs with the Core 2 Duo processors. A nice link here were the reports that it has been noted that i7 processors in Windows boxes with Radeon 4800 series cards are having similar issues.
9 - All new iMacs come with the Bluetooth keyboards and Magic Mouse, with a newer Bluetooth card.

There was a nice listing of steps to take posted earlier, which makes sense.
- Unmount and remove all external devices and quit all running applications.
a - Get the firmware update if not already done. Apply it.
b - Shut down the computer.
c - Here's the rub step - zapping the PRAM with a bluetooth keyboard, doesn't always take.
--- Get a wired keyboard and then restart the iMac, holding the Cmd(apple)-Opt-P-R keys as soon as the chime is heard. Keep the keys held down until a total of 4 chimes is heard. Allow the computer to boot up.
d - Restart the computer holding the 'D' key after chime. It will go into the AHT. Run the test. Restart.

Here is where some have reported success, but then some time later a reversion to bad display behavior.

One of my customers, whose maxed i7 we had for 2 days running constantly with load - never had the issue while in the shop. He got it back and the problem immediately recurred. Went through the steps. Said the steps taken did not make the problem go away, but they disappeared after he turned off the bluetooth keyboard.

Granted this info is too fresh, so we do not know if it really is the clue we needed. But his problem is gone, for now. Only time will tell right now.

I ordered my I7 with a wired keyboard and mouse. I really don't like wireless input devices. I got delivery of my iMac on the 23rd, and so far, no glitches. Now, that doesn't mean they will not appear shortly...no one really knows...but if bluetooth is involved...I'm not using bluetooth...

Using a wired keyboard + mouse would be an interesting experiment for those whose machines are afflicted.

Guys I've got some new information. It has to be graphics card related, heres why. I was around a friends who has the new Imac 27", and we were on windows (BTW, everyone try this). We changed the display from landscape to portrait and every time, this induced flickering/caused the task bar to move up 2/3rds up the screen. What do you guys think?

ps: And this did not involve bluetooth since the bluetooth options do not work under windows. We used a wired keyboard/mouse

Fruscinatemaniac, i think you are right... i can remember my first imac 27" only flickered when i took a photoshopbox and moved it around. When i dropped the box, the flickering stopped. It grew intensively with time.

I also think it's the graphic card.

Message was edited by: Gille_Belgium

I just wanted to add after reading the last 4 posts.
My i5, had the issue from day 1. I use a wired mouse and wired keyboard, bluetooth and airport are always turned off.
pram and d and test and update/firmware have all been done.
Yet it is still happening even worse than before the update.