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

Hello Karen,

I know exactly how you feel. We also have only been using PowerMac Mini-Towers since 1990. They are rugged, long-lasting machines. Other than replacing hard drives over the years as they've worn out, until a few months ago, they were pretty much trouble-free units.

Then my nine-year-old 500 MHz DP G4 Mini-Tower began having serious problems a few months ago, and it now sits on the floor minus a graphics card, minus RAM, and minus a hard drive.

Its companion -- a nine-year-old 400 MHz G4 Mini-Tower -- continues to plug along, although I suspect that the graphics card is going to give out soon, as there is a screen problem.

The third G4 Mini-Tower -- a 733 MHz G4 Mini-Tower -- is slightly newer, having been built in 2000 or 2001. I can't remember now. It's graphic card kicked the bucket a few months ago, so I took the slower graphics card out of the 500 MHz unit, and stuck it in the 733 MHz unit.

So, we've got two still-working G4's, and one dead one.

About a month ago, we purchased our very first iMac -- a 24" 3.06 MHz Core 2 Duo unit. It has worked flawlessly from what I've been told by another family member. Of course, this was purchased at the very end of the 24" iMac cycle, so it is no surprise that it has no problems.

On the other hand, as I have already posted here before, I am very nervous about my decision to purchase the 27" i7, and I also wonder if I acted too hastily in placing the order. I've never been an early adopter before, and given this current situation, I seriously doubt that I will ever do it again.

It's been one day short of three weeks since I finalized the i7 order with our AAR. If it should arrive flawed in any way, I have already decided not to ask for a replacement, or a refund. I will simply tell the AAR to keep my deposit, and to apply it as store credit. I will renew my order once the dust finally settles with the current troublesome situation.

Hello Simon,

Glad to hear that everything is okay...so far. Let's see how you are doing in a few weeks time. That will be the acid test.

I did want to ask you if you could please clarify and substantiate your final statements. You stated: "It would also explain why Apple hasn't found an answer yet. The machines they test in the factory work fine."

How do you know that Apple hasn't found an answer yet? Have you received some top-level Apple news that you are willing to share with us?

How do you know that the machines they test in the factory work fine?

While that would be the obvious assumption -- unless we believe that someone is purposely shipping out defective machines, which I personally doubt -- there is also the distinct possibility that if Quality Control in China -- or wherever the units are being shipped from -- is poor, they might not test as adequately and as thoroughly as they should. So if we assume that they do not test every single machine due to time constraints, plus they do not thoroughly test the ones that they do check, then it is reasonable to assume that they may in fact be shipping out defective machines.

You see my point?

At this point, I am just not that willing to let Apple off of the hook so easily. I think there is plenty of blame to go around for all parties concerned -- both manufacturer and shipper.

jamiebicknell wrote:

p.hugo wrote:
This thread is slowly disappearing from google results... I'm worried about it.

I myself am concerned by the fact that this discussion thread is quite rapidly dropping down the search rankings. At the time of writing this this thread appears last on Google.com for the same query I used 2 days ago when it appeared first.

Searching Google for "imac 27 flicker" let's this thread pop up at #4 on the first page. So I think we may blame Apple for quite a lot, but not for manipulating Google.
Btw: the search returns some 33,000+ results ... quite a lot for a minor problem.

Warren:

You wrote, "...possibility that if Quality Control in China -- or wherever the units are being shipped from -- is poor, they might not test as adequately and as thoroughly as they should. So if we assume that they do not test every single machine due to time constraints, plus they do not thoroughly test the ones that they do check, then it is reasonable to assume that they may in fact be shipping out defective machines."

Onset of the flickering issue varies--can be delayed by a week or more. Some machines don't suffer from the problem. At least right now, those machines that suffer apparently have intermittant symptoms; frequency seems to increase with time and use. At least at onset, rebooting machine appears a temporary fix.

IMHO, unlikely an intermittant, delayed, etc. symptom (vs known cause) would be detected on an assembly line.

Warren Beasley wrote:

I did want to ask you if you could please clarify and substantiate your final statements. You stated: "It would also explain why Apple hasn't found an answer yet. The machines they test in the factory work fine."

My comments simply refer to the theory that these problems are only occurring once the machines have left the factory. Therefore, any attempt to diagnose by testing the machines on the production line will not produce an answer. If this theory is in any way correct, then there's no reason to believe these machines aren't being produced to the usual Apple standards.

I ordered my iMac 27" i7 on Black Friday. It's scheduled to ship on Dec 11th, and arive Dec 18th. In light of the reported problems I'm contemplating cancelling the order and waiting to the issues are resolved. What would be interesting is if we knew how many units Apple has shipped so far and how many of them have been defective. At least we would have an idea of the percentages.
Keeping my fingers crossed.

-={Steph}=-

Mine's been okay and then it started flickering randomly after about a week.
Seems to do it about 15 minutes after startup while the Mac is still quite cool. Flickering stops for the rest of the day after a reboot.

I've noticed hard drive activity each time it flickers which makes me wonder if it's software related, might just be a coincidence though.

I'm hoping this is a software issue as I really don't want to send this new Mac off for repairs.. Why won't Apple publish anything about this? It seems to affect many new iMacs! I've been a Mac user for years and have always believed in the good build quality - this is unacceptable.. What's going on?

We are in week 48 of 52

On google.it it is on 16th position with "imac 27 flicker"...
I'm not sleeping with opened eyes.

BTW: this isn't a minor issue anymore. Also the number of batch seems to solve nothing. I read about many users on this forum with week 47 that have the same problem.

Come on Apple... Xmas is behind the corner, give us a present and tell us what we have to know!

Stephanie, I think you should stay the course and very likely will not have any problems as I have noticed a decline in the number of reported problems compared to when the i5/i7s began to ship. My i7 may arrive by Friday; it's spent a day in Alaska, but I hope it's on its way again today. Certainly I am concerned too that it may arrive damaged or soon become defective. But for purchasers in Canada who purchased from Oct 31 through Dec 24, you have until Jan 9, 2010 to return it for any reason. Normally you only have 14 calendar days. So the sooner you get your machine, the longer you have to know if you want to keep it. Of course the hardware comes with a one year warranty but that is different than the return policy, since warranty items would normally be subject to repair rather than return and replacement or refund.

That said, I'm still optimistic that it will be fine after all assuming that the serious problems affect a minority of machines. My machine has serial number W8948 meaning that it was built in week 48 of year 2009. Your machine is going to be built in week 49 or 50 so even less likely to have problems as I'm sure Apple is making changes to address problems.

Misterzeee, what are the first four digits of your serial number on the iMac? For instance, my serial number begins w8948 which means it was built in week 48. When did you receive it?

Karen, "seduced" is a good way to put it. Please read my post to Stephanie. In a nutshell: I would stay with your order, hope for the best, return/replace it if it's defective but you don't want to assume it's going to be defective as I am sure the serious problems do not impact a majority of the machines.

Dewarnecke, watch it over the next week and see if the problem repeats or escalates and then decide. If you are in a country allowing you until Jan 9, 2010 for a return rather than repair under warranty, you might wait longer and at least your next machine will be a later build and hopefully problem free. No harm in calling to report this first instance if you want it on your file with Apple.

Stephanie,
I've had my i7 for 9 days now and it's been zero problems of any kind. That wasn't true of the Core 2 Duo I bought shortly after release. Maybe the later builds are ok.

I am actually having the flickering/tearing issue with my 24" LED Display when it is connected to the 27" iMac. The LED Display will flicker for about 10-20 minutes after the iMac is turned on after sleeping overnight or while I'm at work. I am in contact with AppleCare but the agent did not have a solution for me and had to refer to engineering. At this point, I'm waiting on a response from him.

I have replaced the iMac one through a retail store and both times received iMacs manufactured in week 40.