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

@ttcircus: Ohhhkay... agressive much? Calm down there dude. We're here for solutions, guidance and advice. If I wanted a flamewar I'd go to 4Chan.

Good Lord, what is up with people on the Internet - they behave like childish cavemen.

BTW - happily running my Mac for almost a month now with no freezes or forced shutdowns... solution still working! Good luck nailing this bug down, Apple. We know you can do it

How do you "grab" the kext extensions. Do you just copy and paste or is there more to it?

Thank you for posting your fix and the instruction, but I need really a little more info to get it right...

I have managed to change the kext files for the fix. I found the kext helper software worked easily to replace the 10.6.2 ATI drivers and then had to do a hard reboot.

To spell out what I did starting out in 10.6.6 - I reloaded 10.6 snow leopard from the disc and went back to 10.6, then downloaded the 10.6.2 combo update and updated to that. After a restart I went into System > Library > Extensions and looked for my ATI card number which was ATIRadeonHD2600.kext (select the one that is listed in your System Profiler under graphics cards) and the related files, ATIFramebuffer.kext & ATISupport.kext. I copied and pasted these to my desktop. Then I downloaded 10.6.6 combo update and updated to that. After the restart I took the 3 files on my desktop and dragged them into the Kext Helper window and pressed Easy Install and waited as it found and replaced those files. In my case I had to do a hard reboot and then my computer restarted as normal. I really hope this is the fix that we have all been waiting for.

I hope this helps some users who have not been confident enough to try it out - yet.

Message was edited by: mediaguru2

Message was edited by: mediaguru2

I did the fix a few weeks ago. My iMac 7,1 ATI2400 was freezing numerous times a day. I have been freeze free for a few weeks now. I have owned Apple products for years and have never been frutrated until now. I have reported numerous times to Apple concerning this problem and even after numerous updates, they have yet to fix this. Glad that a fix was found, even though it wasn't Apple that fixed it!

Having followed this thread for a few months now and my iMac freezing every couple of weeks since upgrading to 10.6.6 from 10.5.8 (I have written before in this thread), just over two weeks ago my computer froze and just would not start again. The back of the monitor was so hot that I could have burnt my hand. As it just scraped in under Applecare, I took it to my local Apple store and they found that the hard disc had been spinning too fast and had been overheating until it would no longer work. They have replaced the hard disc. Unfortunately my Time Machine was backing up at the same time and the backup was damaged. I brought the computer home after they manually copied my files over but almost nothing would work or open and I could no longer sync with Mobile Me. They were able to repair the Time Machine and today I picked my computer up for the second time and so far, all is back to what my computer was like before all the problems started.

I mentioned the kext files and the technicians didn't know anything about them but did say they had seen a number of iMacs the same age as mine with the same problem I had. This makes me wonder if the hard disc they used in this model only has a life expectancy of about 3 years. I have left my iMac on for 24/7 for almost the entire 3 years - it never goes to sleep as I run a shared network through it for my iphone and MacBook.

I will be interested to see how my computer is in two weeks - the longest time my computer would run before freezing. I am running 10.6.6 with all the latest software updates. I also wonder if the kext file is related to an application which only those suffering these problems all use on their imacs. I have also noticed that my computer is now running considerably faster than it was.

I really do not think it was the hard drives that were going out. That said, I did replace mine a couple years ago with a 2 TB drive and after installing, I never had the problem until 10.6.2 With all the screen freezes I had, I never had my iMac get hot nor the the hard drive spin to fast from what I can tell. I replaced the kext files and mine has been freeze free for weeks and runs faster than it did before. I am glad you had apple care, mine had already expired. Glad you got the HD replaced!

I have to concur that it wasn't the HD, not to ignore the possibility though.
The symptoms were:
- SPOB (Spinning Beachball of Death)
- Mouse worked and continues to track, but no graphics.

Led me to believe that it was either a HD issue, or graphics issue.
For part of the troubleshooting, I backed up the machine with time machine of course to an external drive, then the following:

1) Tried other users accounts, and a new fresh "Temp" account, no different.

2) Low level formatted the internal HD, installed the OS fresh, updated, and then just brought the user back. I thought all was fine, then about a week later having the same issues. Although, I only originally tested about 30 minutes and figured problem solved, as this was a relatives computer.

3) Installed fresh OS on an external drive on Firewire, tried for a while, seemed good, moved over the main user from TM. Then booted from the external drive, and unmounted the internal drive. within 2 or so hours, same issue. I think I was led to believe it was working fine because it did take some time to get to 10.6.6 which is where the issue comes in.

4) Attempted to boot the machine, and then control it with nothing but ssh, leaving a shell open on another machine. once it locked up (Since it only seemed the graphics weren't drawing because the mouse WAS tracking). Guess what, when the graphics stopped, even though the mouse was tracking, the ssh session locked too.

5) Followed advice on this forum, and issue resolved.

However, I will report back now, that I had some issues installing other updates. I guess I hadn't installed all updates prior to replacing the kernel extensions, as I was fearing lockup again. Software update was throwing an error. Didn't note, Sorry.
I ended up installing the updates to security and java, 1 by 1.
Software update would not allow Safari 5.03 to install, guess it needed 10.6.(x>2) so I decided to download it manually from apple support downloads, it installed, then got prompted for a few more java updates. All seemed good. Few hours after leaving it running, lockups again. and the next time I could not even boot from the internal HD.

So all in all, I ended up going back to 10.6.2 and installing all updates while ignoring the 10.6.6 combo updater. It's back with the end user, and working fine with no issues so far, with all the original hardware. For now I've turned off automatic updates until this is resolved.

Yeah, bummer to not be able to bring down updates, kinda pathetic actually for apple and ATI. They need to work together on this.

So no Driver downloads from ATI or AMD?

I did my my fix last week and all seems to be working fine. I downloaded some updates including Safari 5.0.3 and a Java one and all worked fine - no sign of any issues. I will be careful the next time updates are there to download and think twice before I download them based on your account. Thanks.

Well, if it had been my computer, I would have stayed with the fix. But since it was a "Not too Savvy" relative's computer, I decided to just leave it at 10.6.2 for safety's sake.
I can remote into the machine at any point and apply updates, once I know it's been resolved. But until then, this way I know they'll stay up and running.

i put a small walktrough together, if you are not afraid of terminal, you might find it helpful to resolve the frosty ati driver issues.

look here:

http://discussions.apple.com/message.jspa?messageID=13089239#13089239

If I don't have the 2 original install disks, only the 10.6.6 retail disk, what would be my best course of action?

Someone in this thread has graciously uploaded a link to the old (good) drivers. The link is http://krzysztof-turek.com/apple/1062atikext.zip when you click it it will download the drivers and all you have to do is find out which one matches your card and follow the instructions also posted in this thread.

That's what I did and have been running freeze free since the fix!

WARNING: make sure to have some sort of backup before attempting this fix just in case something goes wrong like it did for me the first time I tried it (I didn't follow the steps exactly)!

Can you put the steps up that you went through as well for us to try?

I'm in agreement with Simon, if you could then I'd be willing to try it for myself...

My Mac has crashed 3 times now today I was going to try and hold out for the 10.6.7 update, but if anyone has the steps to let me do it now i would be eternally grateful