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

Hello Jacques,

Don't worry; I perfectly understand that everything we say in these forums is a matter of *personal opinion*. That is why we are on this side of the fence, while Apple technicians are on the other side.

I just read under "ATI Avivo Video Post Processor".

Interesting . . . so there is a lot of post-processing going on.

Regardless, even if it were to work, it would STILL just be a band-aid on an uncorrected physical problem.

It seems to me that if this is truly Apple's intentions with the upcoming firmware update, then, as we stated earlier, they are fighting against what they really know needs to be done; that is, replace ALL defective LCD screens.

Correct?

Message was edited by: Warren Beasley

Hi Warren,

I always avoid to judge someone on mere intent.

They sure have more informations than we have. They know exactly how many iMacs are reported faulty.
But my contact with Apple support was first class. My machine will be serviced when I will decide.

I have 3 year warranty, not in a hurry. I love this computer and used it every day.

Only 2 concerns rarely 'flickering' screen and voracious mouse!

Take care.

Jacques LAPORTE wrote:
Hi Warren,

looking at the specs of the ATI 4850 (see what they call 'ATI Avivo Video Post Processor'), maybe they could have a firmware workaround

Hi everybody,

I usualy follow another more "yellow-oriented" thread, but since the discussion has shifted in this direction, let me add a few words to the many that have alreday been written here ...

I'm at my 3rd iMac 21.5" (weeks 49, 02 and 04) and they've all shown yellow tinge _to different degrees_.

Therefore I am extremely skeptical (to say the least) that any piece of firmware, even a very clever one, working blindfolded in the bowels of a machine could be able to compensate this anomaly.

Unless ... unless for some combination of factors the origin is in the firmware itself, but until now it doesn't seem the case.

Hi Paolo,

You are probably right.

But there is slight hope : the LED backlight diffusion layer is apparently out of alignment - on most machines - at the bottom-right of screen. I was thinking of a kind of compensation.
Pure speculation, I know. And off topic, sorry.

Hy,

I´ve connected my Samsung LCD TV with my imac 27", and there is the same Problem with the flickering.

In last time it has become more often.

I have my imac now since 3 months (before i was using windows pc´s since 12 years), and at the beginning there was the first flickering after the third day using it!

After one month the black stripes flashed up every 3-5 hours i was working with it.

And now my screen is flickering every 15-30 minutes!!!

I hope that apple has a good, and first of all a FREE support service!


PS.: Sorry for my english

Max, this is a real important information.
If that's true (and i don't have anything to say it's not), this means definitely that the flickering/tearing issue is in the ATI video card firmware/software.

Have you experienced the yellow thing problem too? If yes, does it appear on the LCD TV or only on the iMac?

Hallo Max,

your English is better than mine, but listen, you should contact Apple Support. Their service is first class. The problem is, that at the moment nobody knows exactly what's the fix. Very probably they'll tell you to wait until February, because there could come out a software solution. We have here a lot of rumors, but no clear anserws, so the best you can do is to contact Apple Support directly. Good Luck!

... this means definitely that the flickering/tearing issue is in the ATI video card firmware/software.

Ciao Ettore,

the problem is, that we already have seen reports here, that the flickering issue was seen on the iMac-screen, but not on the second monitor.

citrus101 wrote:
the problem is, that we already have seen reports here, that the flickering > issue was seen on the iMac-screen, but not on the second monitor.

Ciao citrous,
i'm sorry, i started to follow this thread really late. Read 230 pages or so would have took a long long time.
Have been already posted about the yellow ting issue on both iMac and external LCD monitor?

This is one of the big questions here? Has the yellow tinge to do something with the flickering issue or not. My opinion is, that there could be first a pixel panic (flicker) and the yellow tinge comes after this panic. I don't think that these problems are completly different problems, but I'm not an expert and my biggest problem is, that I don't have a new iMac ... still dreaming

Hello Citrus,

But the problem is that some machines have the yellow tinge, while they do not experience the screen flicker . . . such as my machine.

I imagine that there may be others who experience the flicker, but not the yellow tinge as well.

Maybe you had only one short flicker. It's really what I'm thinking. The yellow tinge could be the result of a pixel panic.

So I have the same flickering, blank-out of screen, and the dock appearing suddenly in the middle of the screen with some distortion. Sent back my iMac 27" two times for repair. Both times they replaced the video card (ATI Radeon HD4850). Problem is still not fixed. I am going to return this machine and ask for a refund, since they simply do not seem to be able to fix this. Or maybe get a MacBook pro. It is really bad that Apple products are affected by such a major flaw. Although support from Apple has been quite good in my case, it didn't fix it. I am depending on this machine for my daily work and cannot afford to miss it for another two weeks. P.s. I do not have the yellow tinge.

Message was edited by: Spammerboy

citrus101 wrote:
Maybe you had only one short flicker. It's really what I'm thinking. The yellow tinge could be the result of a pixel panic.

Citrus, while I suppose that is possible, I view it as being highly unlikely; the reason being that the historical record that we have seen in this thread indicates that once the flickering begins -- regardless of how sporadic and intermittent it may be -- it only continues to grow worse. In short, even if my machine did experience one flicker which I didn't happen to observe, surely it would have grown considerably worse over the last ten days that I've had this machine in my possession. Don't you think so?

You're absolutely right, but there're so many things we don't know. There could be a pixel panic without a visible flicker, there're issues behind these screens nobody understands. There is one interesting fact: We have a lot of iMacs having both problems and we heard that many people don't notice the yellow tinge. I think it's the complete configuration making all these problems and we should just consider the possibility that all issues have the same cause. But Warren, it's also possible that I'm totally wrong, it's only my opinion.