New iMac 27inch screen flickering/tearing/shutoff

Strange as I have just come of the phone (with tier 2 support Applecare in Cork Ireland - I live in the UK) and they are not saying it is a hardware issue. He did read to me a memo with status "Need to know basis only" that stated that 10.6.2 should have fixed an identified graphics issue (perhaps not related though). They are sending me log capture software to activate if it happens again and then I will e-mail them the log files to pass to engineering to analyse.

I don't want to swap it out (like others on this thread) and then encounter the same problem again with the newer machine so I am going to do this before swapping out the machine, so hopefully they fix the recognised problem and me and the iMac can live happily ever after!

Elroyofderovers wrote:
Strange as I have just come of the phone (with tier 2 support Applecare in Cork Ireland - I live in the UK) and they are not saying it is a hardware issue. He did read to me a memo with status "Need to know basis only" that stated that 10.6.2 should have fixed an identified graphics issue (perhaps not related though). They are sending me log capture software to activate if it happens again and then I will e-mail them the log files to pass to engineering to analyse.

I don't want to swap it out (like others on this thread) and then encounter the same problem again with the newer machine so I am going to do this before swapping out the machine, so hopefully they fix the recognised problem and me and the iMac can live happily ever after!

Interesting. Well, it's not unusual for Apple support to say different things to different people. However, they wouldn't offer to swap out a totally usable with the odd flash machine, if they in any way thought it was firmware related. I was very clear about this, saying that if they did think Firmware was the most likely cause then I'd be quite happy to wait for an update, unless it got worse of course.

I see, new to me - virgin applecare user!

Yes that is a good point.

One question: How do you quote from a previous post? Not a big forum user either!

I receive my iMac i7 tomorrow and am scared to death that I'll end up returning it immediately. My question is - are there any of you who have received the i7 and have no issues with it? What are my odds of getting a flicker? Keeping my fingers crossed.

Elroyofderovers wrote:
One question: How do you quote from a previous post? Not a big forum user either!

Just click on the 'speech mark' above the reply text window.

@justgotamac

Returned my faulty flickering 27" iMac last Thursday (12th Nov), for an immediate replacement. The replacement was picked from the _same batch_ as the faulty one from a UK department store. I'm into the 5th day with my replacement, and so far so good! ..

A software defect is highly likely, IMO. We know that the issue:

* affects both Radeon 4670 and Radeon 4850 cards, meaning that a GPU failure is highly unlikely - besides, the Radeon 4850 has been in the 24" iMac for some time now
* affects both Core i7 and Core 2 Duo models, meaning that a motherboard failure is highly unlikely
* affects external displays as well, meaning that a panel failure is highly unlikely
* goes away temporarily after a PRAM reset
* cannot be replicated

If it is hardware, I can only see two possibilities. Either that it is related to the DisplayPort, or that we have two similar issues - one in software and one in hardware, and we're getting too much data that is confusing the issue. I figure that the first is a possibility, because if you connect something to the DisplayPort, the iMac is supposed to detect that and put that on the screen instead. If the system incorrectly detects something coming in on the DisplayPort, it might cause flickering as it switches back and forth between the two.

Note that I ran some torture test on my iMac yesterday, testing the cooling system, and had no issue during that or when cooling down. At least my issue does not seem to be heat related.

Simon (UK) wrote:

Elroyofderovers wrote:
One question: How do you quote from a previous post? Not a big forum user either!

Just click on the 'speech mark' above the reply text window.

Thanks!

I too thought it would most likely be Firmware related, especially as there were issues with the early 2009 24" model and the 4850 GPU which required firmware updates to solve. I've also given the system a good workout playing both COD4 and Bioshock without any problems whatsoever. Like I said in my previous post, the information I was given by Tech Support is that they're aware of the problem, and at this time they will be swapping out any iMacs showing this problem. Beside, they wouldn't offer to give me a new one if they thought they could solve it with an update.

I hope it's firmware problem but IMO it's more like a hardware issue.
Because we use the same software (firmware ,driver) but some people stated that they don't have the flickering problem.
That probably means I have a defective imac.(maybe defective display or logic board)

Anyway my second imac isn't flickering like mad like some VDO on youtube.
It happens about 2-3 times a day.

Have anyone tried booting iMac in Bootcamp to see if the problem persist on Windows?

Here's an update on my situation:

After experiencing a flash, a blackout, and the weird menu-bar-jump-to-the-middle-of-the-screen phenomenon last night, I decided to give Apple a call this morning to see what the next step was.

The first advisor I spoke to said he thought he'd heard of the problem before, and after I explained that I'd alredy reinstalled the OS and cleared the NVRAM/PRAM, he quickly elevated my call to a senior advisor.

The senior advisor had me run the Apple Hardware Test (reboot to OS DVD while holding "D") which didn't discover any problems. He then had me disconnect my iPods from my iMac and send him my system configuration (System Profiler > File > Send To Apple...). After that, he recommended that we replace my iMac. Unfortunately, I wasn't allowed to keep the current 27" iMac until I received the new one, but I was assured that I'd "move to the front of the line" in getting a new one.

I didn't get a warm fuzzy from the senior advisor I spoke to that Apple has any clue what's really causing this issue. I was told that my returned computer would be thoroughly analyzed for problems and hopefully they'd learn something...but that won't make the replacement fault-free. He did say that this appears to be a relatively isolated problem and that I should rest assured that my replacement iMac will be a-okay. I did explain to him that I really didn't want to continue to go through the hassle of returning computers, but he said that since I've got a trouble history established, the process should go smoothly should more problems arise.

I sure hope Apple figures out what's going on quickly. Otherwise, if my new machine shows up with the same (or worse) issues, I guarantee they're going to start looking for environmental or configuration peculiarities unique to me as the culprit.

Schwa72 wrote:
The first advisor I spoke to said he thought he'd heard of the problem before, and after I explained that I'd alredy reinstalled the OS and cleared the NVRAM/PRAM, he quickly elevated my call to a senior advisor.

The senior advisor had me run the Apple Hardware Test (reboot to OS DVD while holding "D") which didn't discover any problems. He then had me disconnect my iPods from my iMac and send him my system configuration (System Profiler > File > Send To Apple...). After that, he recommended that we replace my iMac. Unfortunately, I wasn't allowed to keep the current 27" iMac until I received the new one, but I was assured that I'd "move to the front of the line" in getting a new one.

I didn't get a warm fuzzy from the senior advisor I spoke to that Apple has any clue what's really causing this issue. I was told that my returned computer would be thoroughly analyzed for problems and hopefully they'd learn something...but that won't make the replacement fault-free. He did say that this appears to be a relatively isolated problem and that I should rest assured that my replacement iMac will be a-okay. I did explain to him that I really didn't want to continue to go through the hassle of returning computers, but he said that since I've got a trouble history established, the process should go smoothly should more problems arise.

I sure hope Apple figures out what's going on quickly. Otherwise, if my new machine shows up with the same (or worse) issues, I guarantee they're going to start looking for environmental or configuration peculiarities unique to me as the culprit.

Sorry to hear that you weren't able to keep the old one until the new one arrives - I don't know why these things are so arbitrary, but then as your symptoms are a lot worse than mine it might've had something to do with it. I only ever get a slight flash on the desktop, and that is so irregular that hours can go by without my noticing it (I guess some of them may simply happen while I'm not looking). Anyway, even with this limited symptom Apple still felt a swap was in order. They're obviously taking even the smallest amount of flickering quite seriously.

Simon (UK) wrote:

Sorry to hear that you weren't able to keep the old one until the new one arrives - I don't know why these things are so arbitrary, but then as your symptoms are a lot worse than mine it might've had something to do with it. I only ever get a slight flash on the desktop, and that is so irregular that hours can go by without my noticing it (I guess some of them may simply happen while I'm not looking). Anyway, even with this limited symptom Apple still felt a swap was in order. They're obviously taking even the smallest amount of flickering quite seriously.

That's what's so strange...I've only had the issue three times, and only once (last night) did it do anything more than flash briefly (I got the black screen and menu bar problem). After the PRAM reset, the problem didn't return...even after having slept all night. It's just that this issue seems like a ticking time bomb, so if Apple's willing to replace the system, then I'll oblige them.

I still think it might eventually be fixed with a software/firmware update, but unfortunately I won't know that for sure until after my 14-day return window is up. And if it turns about to be a bad batch of hardware, I don't want to have to settle on a repair just because I kept the original machine betting on it being a firmware/software problem.

Message was edited by: Schwa72

Well I will be receiving my first ever Mac the I7 on Thursday and am hoping for the best. The good news for those of us who ordered after November 1st is we have until January 9th for returns.