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  • 90. Re: New iMac 27inch screen flickering/tearing/shutoff
    bfreebody Level 1 Level 1 (0 points)
    Hey Jan, all,

    I have had exactly the same issues with my imac 27" shipped from shanghai.

    The 2-3 inches of static appear at random intervals on the screen, I've also experienced the screen going completely blank from time to time.

    I called apple last night, me and Alan (the apple tech) pulled the cable for 30 seconds to reset one internal compontent (I forget which, sorry).

    Prior to my call in I reset the apple (EProm?) by booting whilst holding down option + control + P & R.

    We also performed an EXTENSIVE h'ware diagnostics test using the boot disk by holding down the "D" key during boot - this test seems to be a memory test although I don't have specifics although no issues were reported at the end of the test.

    Still seeing the same flickering although at a lesser degree, haven't seen the blank screen although I don't have a huge amount of faith that the issue is over.

    I will edit this post later with my model number, perhaps people can share theirs to see if we are sitting on a bad batch of graphics cards, batteries, etc.?

    The main reason I though to post was to encourage other people to log a call with apple.

    As a side note a friend of mine bought a machine at the same time as me which also exibitied the same "flickering" however his is now working as best I know.

    Perhaps it is s'ware perhaps h'ware - for those who haven't - log a ticket with apple and hopefully they will join the dots their side of things more quickly.

    All the best,

    Ben.
  • 91. Re: New iMac 27inch screen flickering/tearing/shutoff
    gmaxflite Level 1 Level 1 (0 points)
    Is it really bad luck ?
    Even with the 10.6.2 update (16 hours ago), now the flickering is back again.
    I will try again unplugged the imac, and reset the PRAM.
    i'm getting frustrated and angry, hey ***, is there a kind of big brother inside my computer, as i'm writing this sentence, there was just a blackout.
    i need to relax.
  • 92. Re: New iMac 27inch screen flickering/tearing/shutoff
    Brian Pratt Level 1 Level 1 (15 points)
    I installed the 10.6.2 update last night and I'm seeing the horizontal bar flickering this morning. So the 10.6.2 update didn't fix everything, at least.

    For the record, I also had tearing and my display wouldn't wake from sleep before the update, but no Flash video performance issues. I haven't seen any of those issues since the update yet, but it hasn't been very long, either.
  • 93. Re: New iMac 27inch screen flickering/tearing/shutoff
    jmczaja Level 1 Level 1 (0 points)
    I installed the 10.6.2 update last night and had the same flickering issue this morning.. I will check the driver versions as suggested by 'macotub' when i get home this evening I can confirm that 10.6.2 DID NOT fix the issue on my machine at least. I hope the drivers are the culprit and i can fix this by updating them as suggested earlier in the thread. Stay tuned..

    -jay
  • 94. Re: New iMac 27inch screen flickering/tearing/shutoff
    Edward Boghosian Level 4 Level 4 (1,395 points)
    My suggestion would be: If the flickering occurs within the return period, I would return the computer and get my money back. After this is all sorted out, then buy the next version. I wouldn't call Apple help or do anything to fix it up. If in time, return for a refund. This will have an affect. But if all of you are dying to have the new model-then that is another story.
  • 95. Re: New iMac 27inch screen flickering/tearing/shutoff
    jmczaja Level 1 Level 1 (0 points)
    OK, here's what happened when i updated the kexts using the files mentioned earlier in the thread.

    I check my kext and they were indeed from Sept 10th, so i then replaced them with the ones from Nov 3rd.

    I attempted to reboot but before the computer showdown, I got an error that it could not load the kexts because they were installed incorrectly..

    I then started the machine and proceeded to 'repair permissions' and rebooted the machine again.

    I now have a flickering mouse pointer and odd graphics glitches. When running the 'kextstat' copmmand from Terminal, I do not see any ATI kexts loaded? What am i missing?

    Thanks
    -jay
  • 96. Re: New iMac 27inch screen flickering/tearing/shutoff
    MSVMark1972 Level 1 Level 1 (0 points)
    Use Kext Helper to install the ATI Kexts

    Link: http://mac.softpedia.com/developer/cheeta-net-8058.html
  • 97. Re: New iMac 27inch screen flickering/tearing/shutoff
    DJRhinofart Level 1 Level 1 (10 points)
    I used Kext Helper to install the latest drivers from in this thread, and have since not had any issues. I use my iMac every day for about 8 hours a day. It wasn't very obvious at first, just a little 1/100th of a second black blinnk, and then back, but some days it had gotten worse, others, not so bad. My 27" was flickering not as bad as some of the other ones I have seen around, but enough to make me 2nd guess my first ever Mac Purchase. Maybe one thing that could be asked is what Kernel are people running? I have mine running the 64Bit Kernel all the time, and I would go sometimes for a couple days without noticing any flickering. So hopefully between these new kext files, and 10.6.2, everything will be running nicely. I sure hope my 17" MBP doesn't have any problems when it finally shows up.
  • 98. Re: New iMac 27inch screen flickering/tearing/shutoff
    cataldoc Level 1 Level 1 (0 points)
    Mhmm... sadly I talked too early in my previous post... after a couple of reboot the issue is back.

    I will take my iMac back to the store for a replacement at this point.
  • 99. Re: New iMac 27inch screen flickering/tearing/shutoff
    StileselitS Level 1 Level 1 (0 points)
    I have installed update yesterday and today flickering problem every 2-3 min and black screen is back.

    ;((((((((((((((((((((((((((((((((((((( 10 more days and I will bring it back;(
  • 100. Re: New iMac 27inch screen flickering/tearing/shutoff
    Elroyofderovers Level 1 Level 1 (0 points)
    I am another one, first ever Mac. Only had it a week.
  • 101. Re: New iMac 27inch screen flickering/tearing/shutoff
    Soaringoak Level 1 Level 1 (0 points)
    Identical issue here... 2-3" bands flicker horizontally across screen randomly... happening less often is the complete blacking out, but it happens. Apple can either refund my money so I can buy a windows 7 machine or fix this problem. This is unacceptable... and it seems so far that nobody has a clue whether its even hardware or OS related. There are way too many incidents reported of this for Apple to ignore.
  • 102. Re: New iMac 27inch screen flickering/tearing/shutoff
    Dick T Level 1 Level 1 (5 points)
    I had the same problem as others here just 2 days ago after owning this iMac for 6 days. I restarted once and I haven't seen the problem again. Only that one time. Of course I am worried that it will happen again and I only have 6 more days before my return period ends. I really don't want to return it, but... I could wait for the Core i5 and have problems with video and the all new cpu after paying another $300. What to do? We all have somewhat of a dilemma here with no easy answer. Hmmmmm You know, after thinking about it, in spite of some of the experiences documented here, I have a hard time believing it's a driver issue. Like I've seen it only 1 time in 8 days? I just ran the Arabesque screensaver for a few minutes and no problem. I really don't get it. And I thought I was pretty knowledgeable about computer hardware and software after 40 years of experience. Never know everything.
  • 103. Re: New iMac 27inch screen flickering/tearing/shutoff
    AstonMartinDB7 Level 1 Level 1 (0 points)
    I've been thinking about the symptoms and it looks to me as if it is possibly a timing/voltage issue with the graphics i.e. I have seen overclocked PC graphic cards do similar things when I have been trying to find the limits of a card/chipset incrementally increasing the speed and voltage slightly.

    However I could be completely wrong on this?
  • 104. Re: New iMac 27inch screen flickering/tearing/shutoff
    Sin'R-G Level 1 Level 1 (0 points)
    Hello all,

    I have also observed this exact problem in my 27" iMac. The first time it occurred was after running in Windows for a bit--the computer had gotten quite hot so I thought it may be a thermal issue. I noticed it almost immediately after rebooting into OS X at the gray Apple logo screen. I'm not exactly sure to what extent the EFI utilizes software/drivers for video support but if I had to guess I would assume this is a hardware issue, not OS or software-related specifically because it happens during bootup. I could be wrong, though. It eventually corrected itself after the computer had been sleeping, supporting my suspicion about temperature.

    Despite my hypothesis, I am having trouble reliably reproducing it and, in fact, I have had it occur after the computer was powered off for 16 hours. My current thought is either it is not heat-related or it is related to abnormal operating temps, high or low. Maybe my iMac was too cold? Again, it corrected itself after I let it sleep at some point.

    Unfortunately I have not placed a call into tier 1 support for this issue because it is so sporadic I haven't observed it during their business hours. Even if I do call they will certainly step me through the normal troubleshooting fix-alls and I am unlikely to observe the problem anyway. They'll be unable to confirm or repair and I'll be frustrated having spent 30 minutes rebooting, resetting, unplugging for them to tell me to call back when it happens.

    On top of the video issue, it seems like the computer does not sleep properly unless I manually put it to sleep via the OS or keyboard keys. I can hear the hard drive spinning up and down intermittently all night if I don't manually put it to sleep.

    Anyone else feeling a little disappointed? Even with these problems I can't help but love this beautiful machine...I just want it to work properly!
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