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

Thanks for your comments, Hedegaard8. But Apple has no excuse in this case. The first of the 97 pages of posts on this topic is dated March 31, 2010. The release date on these iMac models (mine is 8,1) is April 28, 2008. So these machines started crashing 23 months after they were released. (It happened with a Snow Leopard version upgrade.) I don't think even Apple believes that two years is a reasonable time for them to abandon a hardware model. I mean, Applecare goes three years, which implies they think the useful life is at least that long. In my view, more than three years is reasonable. Note as well someone along the way posted that the Windows drivers for this graphics card (mine is ATI Radeon HD2600) were updated, as the computer does not crash when running Windows in Boot Camp. So this is an Apple-specific problem (and a shame).

Krzysiu Turek, can you help us again please, if this Mavericks challenge persists?

-> sequera: Did you just update your iMac to Mavericks which already was Kext fixed? Or did you update to Mavericks and - after that - run again the Kext fix procedure?

Thanks for your reply!

I've updated the following to Mavericks

iMac 20" Early 2008

2.4 Core 2 Duo

4gb Ram

ATI 2400xt 128mb

I also have the same spec machine running 10.8

Interesting enough, when both machines go to the Imgur website and scroll through the images in Safari, it triggers the graphics glitch.

If the same is done with Chrome, it doesn't.

What are you guys doing when the problem happens on your computer?

P.S I've disable hardware acceleration in both browers as well as doing the Kext fix.

First update to Mavericks, and after run the kext fix procedure.

Just to be completely sure: Did you install all 3 kernel extension files after upgrade to 10.9?

- ATI2400Controller.kext (the one which fits your Mac)

- ATIFramebutter.kext

- ATISupport.kext

In a mistake I once installed only the first kext file and - of course - the iMac crashed. Than I changed the other two and all was fine again.

iMac 20" with ATI 2400XT and Mountain Lion 10.8.5 runs stable as a rock 😉

Can one of you who has installed the kext fixes on Mavericks and believes they have a solution, whether by virtue of the fixes alone or with some combination of settings, check your console after a reboot and see if the kexts are actually loading?

The indication from my log (excerpted above) is that they are not even getting loaded which would make any question of power saving settings unrelated to the kexts.

100% agree with aieronimo. To Hedegaard8: Apple support had the same story when this all started which was, "Never heard of it." And it's true there are a variety of problems that have cropped up on this discussion, but the funadmently freeze that Turek's kext fix addressed works. It takes very little time to install and saves tons of agrrevation. Maverick, who knows? As I said, use it or don't; it's obviously your choice.

But again to others, backup your system and try the fix, especially those 8,1 early 08 models. You might be happy you did.

Hi Again

Had a freeze this morning. I had to hard reboot to clear it! So, my previous attempt which worked then, does not work always! I have checked my console after again inserting the kext fix using Kext Wizard and it appears that those 10.6.2 kexts are not tollerated by Mavericks. I am spending considerable time trying to fix my Mac than actually spending that time using it and enjoying it! So it may be that the kext fix will not work. I wonder if it would accept the 10.6.6 kexts? I might give that a try. Here is my console reading regarding what I found:

Oct 25 13:14:16 localhost kernel[0]: OSMetaClass: Kext com.apple.kext.ATISupport class ATIController is a duplicate;kext com.apple.kext.AMDSupport already has a class by that name.

Oct 25 13:14:16 localhost kernel[0]: Kext com.apple.kext.ATISupport start failed (result 0xdc00400a).

Oct 25 13:14:16 localhost kernel[0]: Kext com.apple.kext.ATISupport failed to load (0xdc008017).

Oct 25 13:14:16 localhost kernel[0]: Dependency com.apple.kext.ATISupport of kext com.apple.kext.ATI2600Controller failed to load.

Oct 25 13:14:16 localhost kernel[0]: Can't remove kext com.apple.kext.ATISupport; services failed to terminate - 0xdc008018.

Oct 25 13:14:16 localhost kernel[0]: Kext com.apple.kext.ATI2600Controller failed to load (0xdc008015).

Oct 25 13:14:16 localhost kernel[0]: Failed to load kext com.apple.kext.ATI2600Controller (error 0xdc008015).

Oct 25 13:14:16 localhost kernel[0]: OSMetaClass: Kext com.apple.kext.ATISupport class ATIController is a duplicate;kext com.apple.kext.AMDSupport already has a class by that name.

Oct 25 13:14:16 localhost kernel[0]: Kext com.apple.kext.ATISupport start failed (result 0xdc00400a).

Oct 25 13:14:16 localhost kernel[0]: Kext com.apple.kext.ATISupport failed to load (0xdc008017).

Oct 25 13:14:16 localhost kernel[0]: Failed to load kext com.apple.kext.ATISupport (error 0xdc008017).

Oct 25 13:14:16 localhost kernel[0]: SMC::smcReadKeyAction ERROR: smcReadData8 failed for key $Num (kSMCKeyNotFound)

Oct 25 13:14:16 localhost kernel[0]: SMC::smcReadKeyAction ERROR $Num kSMCKeyNotFound(0x84) fKeyHashTable=0x0

Oct 25 13:14:16 localhost kernel[0]: IOBluetoothUSBDFU::probe

Oct 25 13:14:16 localhost kernel[0]: IOBluetoothUSBDFU::probe ProductID - 0x820F FirmwareVersion - 0x0207

Oct 25 13:14:16 localhost kernel[0]: **** [IOBluetoothHostControllerUSBTransport][start] -- completed -- result = TRUE -- 0x4c00 ****

Oct 25 13:14:16 localhost kernel[0]: **** [BroadcomBluetoothHostControllerUSBTransport][start] -- Completed -- 0x4c00 ****

Oct 25 13:14:16 localhost kernel[0]: Couldn't alloc class "ATI2600Controller"

Oct 25 13:14:16 localhost kernel[0]: Couldn't alloc class "ATISupport"

Oct 25 13:14:16 localhost kernel[0]: Kext com.apple.kext.ATIFramebuffer - library kext com.apple.kext.ATISupport not found.

Oct 25 13:14:16 localhost kernel[0]: Can't load kext com.apple.kext.ATIFramebuffer - failed to resolve library dependencies.

Oct 25 13:14:16 localhost kernel[0]: Kext com.apple.kext.ATIFramebuffer failed to load (0xdc00800e).

Oct 25 13:14:16 localhost kernel[0]: Failed to load kext com.apple.kext.ATIFramebuffer (error 0xdc00800e).

Oct 25 13:14:16 localhost kernel[0]: Previous Shutdown Cause: 3

Oct 25 13:14:16 localhost kernel[0]: SMC::smcInitHelper ERROR: MMIO regMap == NULL - fall back to old SMC mode

Oct 25 13:14:16 localhost kernel[0]: Couldn't alloc class "ATIFramebuffer"

If I can't find a fix using the 10.6.6 kexts and/or using the never sleep thing for the hard drive, then I will reluctantly have to go back to my working 10.6.8 setup. This hassle is UNBELIEVEABLE! It's almost as though Apple are having a laugh at our expense!! Be back soon to let you know what happens, that's unless I end up with a broken Mac!

From bobtibb:

"So it may be that the kext fix will not work."

This is why I choose to wait a little longer, until something is certifiable.

But I appreciate the effort of the community in trying to sort this out.

Spokes78:

What fundamental freeze are you talking about? Either it freezes or it dosen't, there is no "fundamental" here? right? Or I misunderstood something?

There were all sorts of issue (freezes) that cropped up along the way in this massive thread. Turek's fix addressed the random freeze where the screen would often change color, solid pink, blue, whatever. That's different from an application software freeze or hardware issue. That was the fundamental problem the fix addressed. Good luck.

It is quite amazing that this thread has been going for so long and Apple hasn't even tried to address this. With every system update I come here to see if the problem persists. If we can't update to Mavericks, I'll be rather annoyed.

All the same - big thank you to Krzysiu Turek. If it weren't for you, my machine would be stuck a few OS versions behind.

@Hedegaard8: For heaven's sake, if you're expert on the other side of the fence, when did you ever find a 100% solution that fixed every problem that cropped up in a generation of PCs? Absolutely never, I'm sure. In this case, there are different generations of components installed in the same range of iMacs. Evidently some work better than others with the OS upgrades.

My Mavericks install is still going good without the kext fix after three days. I'm hopeful, but experience tempers that. I like some of the new features in Mavericks and would like to keep using it, but if if falters and the kext fix doesn't work, I'll probably revert to Mountain Lion (I have a backup, natch).

It wouldn't hurt you to backup your clean Mavericks install (athough you can always redownload it for free), then try the kext fix to see if it works, and report the results. That would serve the community. Otherwise, what is the point of just posting that you're not going to do anything until a 100% solution arises? Such a thing will never happen. (Although your report on the hardware mods you tried was good.)

Also, you can still purchase Mountain Lion for $20, but not directy from the App Store. I read that it's available, but from a different channel through Apple. Google it, or check Macworld.com or something. Best of luck.

By the way, I also installed an SSD in my iMac8,1. Zippy. Never going back.

TK111 wrote:

Also, you can still purchase Mountain Lion for $20, but not directy from the App Store. I read that it's available, but from a different channel through Apple.

You can now buy it through the online Apple Store, but what you actually buy is a redemtion code that is emailed to you that you use to download it through the Mac App Store:

http://store.apple.com/us/product/D6377Z/A/os-x-mountain-lion

Although I haven't yet verified this from a direct Apple resource, this seems to confirm significant changes to handling of kexts:

http://pikeralpha.wordpress.com/2013/06/13/kext-requirements-for-os-x-10-9-maver icks/

I had to restore my machine to 10.8.5 but for someone out there trying to get Mavericks to work, it might be worth a try to install the kexts, per these requirements, in /System/Library/Extensions instead of /Library/Extensions and see if they will function. If nobody is able to test, I will try sometime this weekend or early next week.

This may allow us another upgrade or two but it seems that as this gets locked down tighter we will probably eventually be out of luck.

UPDATE: Seems like they've always been installed in /System/Library/Extensions. Guess this won't work but it still points to the changes in Mavericks that have stopped the kexts from loading.

UPDATE: Link to WWDC presentation PDF

Message was edited by: freandc

While I can't verify at the moment, I'm guessing that despite signature issues the kexts would load if they didn't conflict with class definitions already present in AMDSupport.kext . AMD acquired ATI in 2006 so I guess they finally got around to combining the drivers into one AMD file.

Seems like the solution is going to have to involve either removing the AMDSupport.kext and hoping there is nothing else in there that is needed or editing the AMDSupport kext contents to stop it from matching the hardware signatures for the affected graphics cards.