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

just to update - continued to have freezes with just the old kext fix - currently it seems to behave with a daily boot. Thanks for continuing to experiment everyone, will probably apply the updated work around (…hack…) when it freezes next. Console sometimes reports GPU crash, but not everytime - which is the same as ever.

(I also had better stability some time ago by ramping up the fans - like I said, it is a very strange issue)

Hi

Just to update. Since the 'fix' listed previously . . . still purring along! Mac has been in use all day. No probs . . .

Bob

bobtib:Sounds good! I really hope that it is the new fix for Maverics!

Still working! I won't say any more . . . fear of the Apple MIB!

I'm convinced. Another long day with no freezing. Puttin' this issue back to bed until 10.9.1 but also think that it would be prudent to consider the future. Unless someone can produce these kexts with a valid signature (singed using an Apple DeveloperID), some day soon they won't load and we will eventually be SOL.

freandc wrote:

OK, it's a little premature to say without reservation that I've got the kext fix working on Mavericks but here are the indications:

Console messages - loaded the three old kexts with warnings but no errors

-----

10/28/13 12:16:09.369 PM com.apple.kextcache[562]: WARNING - Invalid signature -67061 0xFFFFFFFFFFFEFA0B for kext "/System/Library/Extensions/ATISupport.kext"

10/28/13 12:16:09.670 PM com.apple.kextcache[562]: WARNING - Invalid signature -67061 0xFFFFFFFFFFFEFA0B for kext "/System/Library/Extensions/ATIFramebuffer.kext"

10/28/13 12:16:09.983 PM com.apple.kextcache[562]: WARNING - Invalid signature -67061 0xFFFFFFFFFFFEFA0B for kext "/System/Library/Extensions/ATI2600Controller.kext"

System report shows extensions as follows:

ATI2600Controller:

Version: 1.6.6

Last Modified: 10/28/13, 11:52 AM

Loaded: Yes

Get Info String: ATI2600Controller 1.6.6.25 (7429)

Obtained from: Unknown

Kind: Intel

Architectures: i386, x86_64

64-Bit (Intel): Yes

Location: /System/Library/Extensions/ATI2600Controller.kext

Kext Version: 6.0.6

Load Address: 18446743521834800000

Valid: Yes

Authentic: Yes

Dependencies: Satisfied

Signed by: Unknown

ATIFramebuffer:

Version: 1.6.6

Last Modified: 10/28/13, 11:52 AM

Loaded: Yes

Get Info String: ATIFramebuffer 1.6.6.25 (7429)

Obtained from: Unknown

Kind: Intel

Architectures: i386, x86_64

64-Bit (Intel): Yes

Location: /System/Library/Extensions/ATIFramebuffer.kext

Kext Version: 6.0.6

Load Address: 18446743521834700000

Valid: Yes

Authentic: Yes

Dependencies: Satisfied

Signed by: Unknown

ATISupport:

Version: 1.6.6

Last Modified: 10/28/13, 11:52 AM

Loaded: Yes

Get Info String: ATISupport 1.6.6.25 (7429)

Obtained from: Unknown

Kind: Intel

Architectures: i386, x86_64

64-Bit (Intel): Yes

Location: /System/Library/Extensions/ATISupport.kext

Kext Version: 6.0.6

Load Address: 18446743521831400000

Valid: Yes

Authentic: Yes

Dependencies: Satisfied

Signed by: Unknown

And so far no freezes.

Procedure followed:

1. Install kexts as usual with kext_helper.

2. Make backup copies elsewhere and then remove:

/System/Library Extensions/AMDSupport.kext

/System/Library/Extensions/AMDFramebuffer.kext

/System/Library/Extensions/AMD2600Controller.kext

3. Reboot

My system configuration is:

Model Name: iMac

Model Identifier: iMac8,1

Processor Name: Intel Core 2 Duo

Processor Speed: 2.8 GHz

Number of Processors: 1

Total Number of Cores: 2

L2 Cache: 6 MB

Memory: 4 GB

Bus Speed: 1.07 GHz

Boot ROM Version: IM81.00C1.B00

SMC Version (system): 1.30f1

It would be nice to understand if there has been additional functionality added to the drivers and what features of more recent OS’es won’t work (perhaps AirPlay functionality, for example) but given a choice, I’d gladly give up the new functionality for a stable machine.

I will post again after a day or two and report if things continue to be stable.

Good work freandc, and thanks. Just a note on my own 8,1 w/HD2600. I've run it for years with the kext fix, of necessity. So far after installing Mavericks on the 22nd, without the kext fix, I've had no freezes under heavy usage including HBOGo and other videos. Go figure. I hope it keeps up, but otherwise, I'm retaining all these notes about what to do.

You must have an angel on your shoulder. I hope it holds up -- maybe there is hope for us all. Best of luck!

freandc

Still running smoothly with the 10.6.2 kexts in place! However, silly me . . . I have inadvertantly killed my AMD versions from the Mavericks install! Doh! So, should I need them from the Extensions folder, they have gone! Can you help me out please? I just want to save them somewhere safe! Should have done that anyway. Rather than reload Mavericks onto my external drive again in order to get the kexts. The kexts I need are: AMDFramebuffer.kext AMDSupport.kext and AMD2600Controller.kext. Thank you!

bobtibb,

The forum policy won't allow posting of links to any software that is distributed by Apple (I tried, it kicked back). As soon as 10.9.1 comes out, you'll have them again so I wouldn't worry too much.

freandc

Let's hope your AMD replacement fix holds up for a while to come! Cheers! Bob

I guess I will await 10.9.1 then. Thanks anyway mate!

Bob ;-}}

hello all!

after upgrading to mavericks i noticed that there was another software update. when i proceeded with "update all" it said: We could not complete your update. Your computer’s video card does not meet the minimum system requirements.

gonna play battlefield 2 now, and if my good old 24-inch early 2008 imac won't freeze during the game, i think it's safe to say that the final solution is a winner.

since i upgraded to mavericks, graphics seem to be a little bit smoother, but it might be an illusion..

freandc - thank you for figuring out and sharing your solution to Graphics Card Challenge: Mavericks Edition. We have been crowdsourcing solutions to this problem for more than three years. Thanks to you, the solution that Krzysiu Turek first shared works as well for Apple's latest OS.

I did the usual Kext file updates after my last post but I did still have the occasional lock up at the initial login screen. Usually being unable to enter my password or click to restart or shutdown. I've been offline for a few days bas we've been having some work done on the house but just before I stripped my room out I did try removing the AMD files and moved them to a backup location. Nice to see from your posts that this seems to be the final step in making the fix work under Mavericks.

Hopefully this will have done the trick 🙂 Cheers

I updated to Maverics and did the usual kext-fix. Then I followed freandc's fix with the AMD-files and it works fine!

I have not experienced any issues.

Thank you krzysiu turek and freandc.