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

I've been following this thread for a long time. Extremely useful for those with Apple-forgotten Care Less iMacs. Thank you guys.

I'd like to know if someone has already tested Mac OS X 10.10 Yosemite in any of the affected iMacs. Haven't found anything related.

According to this website, all Mavericks compatible computers will be so with Yosemite:

Quick Update: On June 2, 2014, Apple announced OS X "Yosemite" and it is compatible with all of the Macs listed below that are compatible with OS X Mavericks. However, specific feature support has not been finalized. When specific details are available, this Q&A will be updated and/or a new one will be written.

http://www.everymac.com/mac-answers/os-x-10.9-mavericks-faq/os-x-mavericks-compa tible-macs-system-requirements.html

I'd like to know if someone has already tested Mac OS X 10.10 Yosemite in any of the affected iMacs. Haven't

If somebody has, they are not allowed to discuss it here or they would be ciolating their NDA as well as the ToU here as we're not allowed to discuss it either.

Thank you babowa. We'll know it sooner than later.

I have upgraded to 10.9.5 and I have not encountered any freezing using the new kexts that came with it for Radeon HD 2600 Pro.

I did encounter issue with the external monitor going black for a couple of seconds intermittently. I selected another refresh rate in Systems Preferences -> Displays and then shutdown the computer before starting up again.

So far I have not encountered any issues for the past 2 days.

Seems like they may have fixed the kext but you may need to shutdown completely and then start the computer again for the new extensions to kick in?

The kext now loaded in my system are :

AMD2600Controller version 1.24.38

AMDFramebuffer version 1.24.38

AMDSupport version 1.24.38

ATIRadeonX2000 version 8.24.16

Really? I have to use the old kext since 10.7.... cause the freeze problems

It is certainly working fine for me at the moment and a little faster in fact, why not try by downloading the update package and reinstalling the update. Shutdown the Mac then and start up again. Check that the new kext are loaded instead of the old ones.

If it still doesn't work, try restarting in safe boot and login before restarting the Mac again. I read that it clears certain cached data about the system and sometimes that helps.

Ok. I try it tomorrow.

After this last 10.9.5 update I had a little extra time for some problem solving. I've tried the kexts fixes mentioned in this thread which seemed to sort of halp the issue, but freezes seemed to continue anyway to a point where I was never able to use the computer. I never had any issues prior to Mavericks. I have a mid-2007 27" iMac.

So I installed Hardware Monitor: http://www.bresink.com/osx/HardwareMonitor.html

This made the issue clear - GPU is overheating. The temperature of the GPU specifically goes slowly climbs to it's maximum of 127C and shuts itself off (black screen). Odd that I don't hear the fans turning up... So I installed Macs Fan Control: http://www.crystalidea.com/macs-fan-control

...and there's the issue. The fans are not responding to the increase in GPU temperature. I believe there's an issue between the sensors and the fans in the new Maverick controller. Either there is a GPU fan which is no longer recognized by the logic board, or the ODD fan isn't triggering based on the GPU diod temperature.

Manually increasing the ODD fan (and somewhat the CPU fan) keeps the temperature under control. Changing the HDD fan only makes it noisier. It's still running hotter than it should though, so I'm going to open it up and clean out and dust. I'll update if I find anything more interesting.

Just an update. After open up the iMac I was able to easily rotate the ODD fan to point to the GPU. The GPU was really running hot (I could feel it), but the heat wasn't properly transfering to the heat sink and fan on the left of the machine. I almost never use the ODD and the GPU temp dropped about 20C with this small change. There was not much dust, but I cleaned it out anyway.

It's great having this Mac back. It's 7 years old, but for watching movies, it's still killer.

Hello everyone!

I recently did a fresh install of Mavericks, and updated to 10.9.5 and had no freezes without applying the Kext fixes.

I updated my Canon printer software (the only thing I installed) and had my first freeze the next morning. (someone mentioned that before? could it be that there's a connection there?)

I tried to apply the Kext fixes from Krysztof, using the Kext Helper but according to System Information they weren't replaced (even though Kext Helper said they did) and I had another freeze.

I tried pasting the files into the Library/... folder (and hitting on "replace") and it said something like they cannot be installed, because they are not properly signed and on System information still nothing has changed...

Just installed the SMC fan controller and raised the fans to 3000. Im waiting to see if this might help.

I need to use my mac for my university assignments and this just adds extra pressure. :-(

Thanks for any information and help.

hey! did you manage to install the fix on Mavericks? How? thanks

Hi. After a week i have not freeze updating to 10.9.5 without fixing the old graphics files.

The gpu temperature is around 50ºC like before (i use smcfancontrol to up a little the cpu and hdd fan rpm).

Did you delete the AMD kexts in /System/Library/Extensions?

You should delete AMDFramebuffer, AMDSupport and the AMD kext specific for your graphics card. Or your mac will load the AMD instead of the ATI ones on boot and the extensions will continue causing problems.

For those of you who have time to try the new Yosemite OS X and the freezing issue - you can now download and install it for free from Mac Store.

I still use Mavericks and unfortunately I don't have time at the moment to backup and try the kext files.

Has anyone been playing around with the Yosemite beta and know if it this is still an issue? Not sure if I want to upgrade just yet...