Thank you so much for your solution. My Imac 2008 had exactly this problem. Spend so many hours to solve this frustrating problem. used your solution and NO NO NO craches anymore. Even under the toughest circumstances. Fancooler not needed. Just replace the driver and problem solved.
I'm happy with my IMac again. Thanks a mil
This fix has worked like a charm for me until 10.6.8. I did the workaround like before, but on reboot I get a gray panic screen and the "you need to restart your computer" dialog. This has happened multiple times. I can't sync my iPhone with iTunes because I don't have the latest version installed but can't install because I can't get 6.8 working. Can I just go straight to Mountain Lion from 6.7? Anything I'm missing in order to update to 6.8?
Yes, the fix only works with 10.6.8, if you previously switch to 64 bit kernel. But this only works with the 2008 machines, I think. Not with older ones.
However, you can try out the 64 bit kernel by holding both of the keys 6 and 4 during startup. To switch permanently, you have to type this:
sudo systemsetup -setkernelbootarchitecture x86_64
You can check whether you really run the 64 bit kernel in “About this mac”,
e.g. if you run the 32 bit kernel (default), it looks like this:
Hello all. After reading dozens of pages here, i decided to try the solution @page28. My machine es an iMac 2008 (8.1) with that famous ati radeon 2600 pro. After updating the drivers as explained, a full panic kernel failure made me recover my system with the original DVD and my timemachine copy. What would be the mistake i made??? Thanks for your support and company
Can't be sure at this distance, but if I recall correctly the kernel panic usually has something to do with whether you're running in 32-bit mode or 64-bit mode, versus whatever version of OS X you're using. May have to read a few dozen pages more to get that straight. I don't remember exactly at this point. I just applied the kext fix to my own machine, same as yours, running Mountain Lion and so far no problem. I have a replaced 2600, but lately getting freezes every ten days or so. That's still too many, so I went back to kext fix.
I have the same iMac 8,1 and video card as you do. I'm running Snow Leopard 10.6.8
Are you running 10.6.8? If so, TK111 is right and you must have OS X boot in 64-bit mode to prevent kernel panics. (At least, this is what I've read on these pages.) Snow Leopard defaults to booting in 32-bit mode. (I believe Lion and Mountain Lion default to booting in 64-bit mode.)
If you do have Snow Leopard, you can boot into 64-bit mode by holding down keys 6 and 4 during startup, but I think it is better and easier to change the default boot mode to 64-bit. Follow Tardigrada's instructions in the post just above yours, or read the excellent links he provided for more information.
Now that you have a working system, I would use the
sudo systemsetup -setkernelbootarchitecture x86_64
method, then install the kext fixes again. That should eliminate the kernel panic (assuming you're running 10.6.8).
I've been running in 64-bit mode for over a year, with the kext fix, and haven't had any screen freezes in that time. There no problems introduced by running 64-bit mode either -- everything works as before.
Good luck and hope it works as well for you.
dear both TK111, and Brian Holmes :
I have 10.6.8 as well and I thought i was using my mac in 64bits mode over the last 2 years or so, but the fact is that i cant prove it, so i'm not really sure about it. It's strange that when i recovered this afternoon my system to it's previous state this morning before the crash (thanks Time MAchine!), i realised that kernel was running in 32 bits mode, so i can assume that i did the kext downgrade in such a bad way. :/ I have just completed the last entire system backup, and put the system running (permanently) in 64 bits mode, so... it could be right now applying the 10.6.2 kxet method...am i right? So far I have not had any freezing, but if it occurs, i'll repeat the kext fix. Thank you all for your help!! (if this fix the problem, it could be the end after almost 2 years of suddenly freezes :/ crossing fingers! )
I think you're doing it right now. If I remember, back when I was using Snow Leopard, the method of pressing 6 and 4 while booting did not work for me. I was still in 32-bit mode. Changing it permanently worked, and then the kext fix worked as well, with no kernel panic. You should be happy with no freezing now. Good luck.
Hello friends: on with the story: as expected, my system crashed again (typical screen full of artifacts). I have to say that it had been going too good since the restoration, but, as I expected, finally crashed. Ok, no problem, I was eagerly waiting for this moment, to apply the fix kext. and ..... Done! It runs seemingly OK, so I'm timing until the next crash. Thank you very much again for your support, and company in this battle. I'll report about the next crash.... if happens! Meanwhile, i'll be 'over here' hidden
Here's a tip. Since I installed the kext fix a few days ago I've been having slow shutdowns (almost a minute). Did a little googling and it was suggested to verify permissions using Disk Utility. Lo and behold, many of these system/library/extension files had differing permissions. Repaired permissions and shutdown returned to 5 seconds. Yay!
By the way, I put a 128GB Samsung 830 SSD in my iMac, which was a thrilling and ultimately successful exploration into the innards. Had to hold it in place with electrician's tape, but I like it.
https://discussions.apple.com/thread/3938355?start=0&tstart=0 is for imac users running Nivada Geforece GT130 graphic cards having freeze or kenel panics since upgrade to snow leopard lion or mountain lion
thank you KrzysiuTurek!!!
my mid 2007 imac wasn't doing good with the mountain lion or lion.. I went to every forum and apple store available to me, nothing!! fought with apple over the phone for hours!! nothing.. did everything humanly possible..nothing.. found this thread.. applied the kext fix... before the fix, i could almost time the crashes to almost every 1/2 hour to 40 min. the first day of the kext fix, it crashed after 4 1/2 hours. which i was more than happy with because i was able to finish what i wanted before it went blank on me. the next day and everyday since... nothing!!! not one single crash!! i cant believe it! its been running strong for 8 or more hours at a time until i shut it down myself because im done with what i need to do, so if your mac is messed up from upgrading.. fix it with this! apple wont do it, they dont care about anybody. the guy on the phone told me that "well, it is an older machine and a hardware problem is bound to happen anyway".. Ya i know! what a jerk! I kept telling him its not hardware..he didnt care.. well thanks again.. mahalo! Jason
I have a mid 2007 iMac 7,1 running 10.6.7 with the kext fix. Every time I try to update to 10.6.8 and apply the fix, it get a kernel panic. I restored from Time Machine and tried the permanent fix to boot with the 64-bit kernel, but it's not supported by my model. So I have 2 questions:
1) Can I install Mountain Lion from 10.6.7? If worse comes to worse, I suppose I can download and prepare a Mountain Lion install onto an external HD from 10.6.7, update to 10.6.8, and then install before a freeze happens.
2) If I update to 10.6.8 and make the change in Terminal to boot with the 64-bit kernel before a freeze, then apply the kext fix, will I still get the kernel panic?
I just haven't really been able to find a clear answer to this. My main problem is that I can't sync my iPhone 5 with my iMac because I can't update to the latest version of iTunes with 10.6.7. If I can do that, I will be happy.
I have a 2007 iMac 7,1 and my machine was incapable of running in 64 bit in Snow Leopard (though I didn't try forcing it in terminal) But I was able to install Mountain Lion, which starts up in 64 bit mode I believe, and apply the kext fix. It has been several months now with no freeze.
20-inch, Mid 2007 Graphics ATI Radeon HD 2400 XT 128 MB
Model Name: iMac Model Identifier: iMac7,1 Processor Name: Intel Core 2 Duo Processor Speed: 2 GHz Number of Processors: 1 Total Number of Cores: 2 L2 Cache: 4 MB Memory: 4 GB Bus Speed: 800 MHz Boot ROM Version: IM71.007A.B03 SMC Version (system): 1.20f4