Q: 24" iMac Screen Freezes since 10.6.3 update - pls help!

I haven't had the same issues. 10.7.4 updated, and still going strong. I'm more worried about Mountain Lion. Will the fix still work I wonder.

update software to 10.6.8

Z

I'll definitly try that. In the meantime, could you relink the most conclusive set of intructions on replacing the kext files if I'm already on Lion, or could you restate them? With 74 pages of replies and many attempted solutions, and people still reporting problems without readitg through the full post, it's difficult to find the pivitol reply. Has there been an update to the utility that you use? Is making the attept 2x the definitive work-around? Is starting up in 64-bit mode a worthwhile test in the interum? Thanks Plenty!

Here is a link to earlier in the thread with the instructions:

https://discussions.apple.com/message/13097053#13097053

Personally Kext Helper bricked my mac after its scripts totally messed up my /System/Library/Extensions directory, so I just moved the files into place myself.

Make sure you have a Time Machine backup before you do this, and look up ahead of time how to boot your Mac in safe mode if you screw this up.  You are messing with system files.  Don't do this if you don't know what you are doing.  Do this at your own risk.  Et cetera.

I backed up the 10.7.4 kexts first:

mkdir -p ~/kexts/10.7.4

cp -a /System/Library/Extensions/ATI*.kext ~/kexts/10.7.4/

I unzipped the 10.6.2 kexts and put them into ~/kexts/10.6.2, then copied them and fixed up ownership and permissions by hand (which is pretty much all Kext helper does):

cd ~/kexts/10.6.2

sudo cp -a ATIFramebuffer.kext ATISupport.kext ATI2600Controller.kext /System/Library/Extensions/

sudo chown -R root:wheel /System/Library/Extensions/ATI*

sudo chmod -R 755 /System/Library/Extensions/ATI*

As in the original instructions, replace ATI2600Controller.kext with the appropriate driver for your system.  I think I also did ATIRadeonX2000.kext, but I don't remember.

Okay all... here is my final verdict. Recap: I have an iMac 24" with 4GB RAM and Nvidia GT 130 with 512MB. Once I went to Snow Leopard and began trying to play any games, Call of Duty, Doom it realy does not matter, they would lock up and I would get rainbow artifacts all over the screen eventually requiring a hard reboot. I since updated to Lion and the machine continued to have graphics issues actually getting worse even if just watching a clip on YouTube and in some cases just from a site with lots of Flash. Daily the machine would get strange graphical artifacts and need to be shut down or hard reset. Occassionally kernal panics would happen.

Taking the adivce of others I took it in to Apple and they did not find anything wrong with their bench test. Still I paid to have a new GT 130 Card installed. 170 Bucks . Got the machine back and it is flawless . Can play games as much as I want and never have any issues any more. They did mention the card may have been updated to prevent overheating. They also said my card had excessive thermal paste on it that may have added to heat issues. Still I believe Nvidia had a bad batch of chips. I am good to go.

On a side note, messing with KEXT files does not seems wise. What you fix will likely create a bunch of other issues in the future with other parts of the OS. I hope everyone else has success. I promised I would share my results, and I am home free now. Best of luck to all others.

The exact same thing happened to me with the exact same graphics card. I understand that it is a revised card. I have been running 2 months trouble free.

With all due respect to our friends with the GT 130 cards, their issue is different from what those of us with the faulty ATI cards are experiencing.  For us, it's the specific set of ATI graphics cards and it's any Mac OS since Snow Leopard 10.6.3.  For the specific ATI card models listed in this very long thread, the KEXT fix works flawlessly.  I've been running it for well over a year and have had no problems.  As an alternative to updating a four-year old iMac to a new graphics card, I highly encourage those with this specific ATI card issue to try it.  As I've said elsewhere in this post, our colleague from (I think) Poland deserves the Nobel Peach Prize for coming up with and sharing his solution.

It sounds like the GT 130 card also had a flawed batch and that Apple did not appropriately address that problem as well.  It's unfortunate that the KEXT work around doesn't help in that situation.  And I agree that a KEXT work around is not the ideal solution.  (Although Apple is not providing a better option.)  But to avoid confusing two separate problems, I just want to clarify that the KEXT fix works for the problem described above.  Thanks.

Oops -- I meant Nobel PEACE (not peach) prize.  Although perhaps a lesser category of Nobel prizes would be appropriate in this circumstance....

I'm sorry you did not intend to write "Peach" Prize, because that's perfect. There should, indeed, be a Nobel Peach Prize for just such circumstances as these.

Also, thank you for clarifying that the original problem explored in this thread and the excellent solution provided was for the iMac 8,1 with ATI graphics cards. (The kext solution worked for me, but even so I got a new graphics card and that works, too.)

Now I'm getting screen flickering and the blue screen with gray vertical stripes on my barely one year old iMac 27" i5. This same thing happened on my last 24" iMac so I eventually got this new one. Yay! I get to deal with the same problems I ad before. Ugh. This is getting ridiculous. I'm definitely not buying a PC but this overheating/screen flickering/random shutdowns is nuts. I expect a LOT more from Apple.

Going to contact them later today and demand a brand new iMac. I can't keep buying a new one every year.

Here's a picture of my blue striped screen of death from about an hour ago.

This thread would seem to link to the question asked by CarlaBlue here...

https://discussions.apple.com/message/18706663#18706663

Question I've asked there appears apposite here, too. Is Apple now too big to listen?

@KrzysiuTurek

Hi there, I am having that freeze problem since SL 10.6.3, I managed to control it but it did not go away and today someone sent me to your thread where you taught how to fix the kext. files.

But I have an aluminum 20-inch imac 7.1 OSX 2.0GhZ intel CoreDuo, from August 2007 running last updates of SL 10.6.8 and my ATI is Radeon 2400XT.I got so tired of this issue  and extensive troubleshooting that did not even upgrade to Lion.

Just want to ask if somehwhere along the way since 2010 you found a fix for something for my imac model and published it somehwere. I filed many bug reports to Apple with no reply.

We are having a paralell thread at the forum here:

https://discussions.apple.com/message/18706756?ac_cid=op123456#18706756

thanks

@CarlaBlue

Hi, you should try to fix the kext with the files:

• ATI2400controller.kext
• ATIFramebuffer.kext
• ATISupport.kext

Because your problem appear since SL 10.6.3 this solution should help, but I can't promise that

It also could be hardware problem, but trying my kext fix is the easiest way to check it - but remeber to backup all of your data. 

@KTurek

Thanks , I'll do that but will read your previous instructions carefully. No, it is not hardware, I am dragging this problem since 2010 and went trough all the dillema:computer went twice to repair, mac was opened to clean all the dust, radical clean installs and bringing files from backup manually,SMC reset, running TechTools and Disk Warrior etc etc etc.You name it, I did it.

I noticed it was my ATI when Firefox started having these odd glitches with pixel artifacts and I had to turn off hardware accelaration or with Photoshop cs5.5 if I use tools that pull on GPU. It happens more sporadically but today I got it again and someone suggested I read your thread because he was trully happy about your solution.

I'll try and come back to tell if it worked.

Hey KTurek, just came back to say that unfortunately I cannot try the kext. solution, my Snow Leopard DVD is already 10.6.3 because my previous one got a problem and I had to purchase this new one.

So now I have the bad karma cd...no 10.6.2.

I'll survive with the random freeze and with my caffeine app and prevent my mac from entering sleep until I'll buy a new computer or maybe I'll try and see if Lion solves it. But thanks for the tip. I hope it will help others though.