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

To be honest I do not really know. At the time I think it was the only graphics card that was built into the MB Pros. After replacing my first logic board I got the screen flickering within days again as well.

ah right, im sure the pros have 2 cards though dont they?

edit: mine has a 9400m and a 9600m GT

Sorry for the confusion, I have a late 2008 MB Pro. They only had one card which is the GeForce 8600M GT.

ah, ok it appears im being an idiot!!

mine was feb 2009 not 2008. has a 2 year warranty from john lewis anyway.

sorry for any confusion (ive had a long day )

Installed the graphic card update wednesday the 23rd, i will be working nonstop in after effects and final cut pro thru the night... i will update every day until I see a flicker/twitch/blackout/glitch/lhbejhfberjkhfqw4lekjfn

Im going to run the computer to its full power and see if anything happens.. fingers crossed.

Installed update, still flickers. Lets try again apple.

My replacement, serial W8950XXXXX, works so far. Cross fingers.

Guys, just a warning. I was on the phone to applecare today (I'm on my third Imac which would not switch on out of the box), and they told me that apple had told them that the firmware update was the answer they should give to people who are complaining about screen flicker. Knowing that this did not resolve the issue, I made sure I let them know that the update has not worked for many people and is probably a hardware issue - they were shocked about this but I think you guys need to voice this to them because it appears that things are progressing very slowly with this issue...

Some people have had luck doing the P-Ram after the install. Did you try that?

I called the Apple store for an update today. (Mine is at the Apple store in SouthCenter Mall.) They said the new screen and cable wasn't in yet and they had no idea when it might come in.

They offered to do the firmware update, reset the p-ram and use some stress diagnostic software on it to see if the could cause it to flicker. The shop is open until 2300 tonight and they said I could pick it up after the test and wait until the parts come in to bring it back if need. They are supposed to call me when the tests are done. So, I'm waiting for their call!

I have mixed emotions about taking it back home, with the thought of having to go through the trouble of packing it up again and fighting my way back to the Mall, etc. if the flicker still remains and/or to get t he new screen and cable.

I like most people have checked MR and threads here for the success of this firmware update worked and to me it looked pretty dicey! I see not many success stories with those that had problems and installed the firmware.

My anger with Apple is starting to build!

We would like to know what's REALLy going on with this issue. I mean, not a single word from Apple to their customers, no apologize, nothing.

Someone from Apple Care told me that the engineers were working on the issue, but it really looks like they have no clue of what's going... wrong.

Even when I read this thread, it looks confusing, frustrating, and the only thing that we can do after installing the graphic update without any kind of success, is to send our iMacs back to China... Seriously, it cost me almost 2600 CAD for my Core i7 iMac, and it's pretty expensive too me for such a pain in the *.

There was a guy on this thread with his 3rd replacement machine and it was not functional. COME ON APPLE !!! i can't believe I came back on Apple computers after my last iMac 8 years ago for this "bag of hurts".

A complete disappointment.

:::::DISCOVERY::::

I fixed it by running hardware test after installing the firmware update.
I want to make it clear that it was not fixed after the firmware update for two days. Hold down the D key during boot with the grey app install disk that your mac came with. It may require a EFI reset after the firmware update.

Well, my i7 is back from the Apple store. I picked it up tonight as the cable and screen they tried to order wasn't available for a while. They did run some stress checks, on the iMac and couldn't get it to flicker.

I had them install the firmware update and after it was installed had them reset the Pram.

So far so good, I have had no flickers or blackouts since starting it up it's been on about two hours now.

I'm hoping that the flicker is fixed now; however I will be monitoring the screen closely! :rolleyes:

My iMac i7 never did have any of the other problems outlined on the myriad of threads on the i7's problems.

If indeed it is fixed I will keep it. If it isn't and starts to flicker again I will take it back when they tell me the screen and cable do come in. I may also invest in Apple care prior to the end of my 90 day period.

Techcrunch now calls the new iMacs iLemons: http://www.techcrunch.com/2009/12/23/27-inch-imac-screen-problem/

They also mention that the new FW update does not work. It is good that this is kept in the news!

And another one: http://www.computerworld.com/s/article/9142657/iMacfirmware_update_fails_to_fix_flickeringproblems

Guys

Apple did an upgrade of the graphics/Display of the ATI Radeon HD 4850 to fix the screen flickering problem of the iMac 27" screen.

I installed it right now, let's see if this corrects the problem.

Merry Christmas

Gabriele Gianolli