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

Bumina,

mine is imac7,1 with HD2400xt.

i installed the good old 10.6.2 drivers 8 hours ago.

they work - that means, OSX was able to load them despite the fact they are originally meant for 10.6.

crowley:Desktop swm$ kextstat | grep ATI

92 2 0xffffff7f813a8000 0x45000 0x45000 com.apple.kext.ATISupport (6.0.6) <77 9 8 7 5 4 3 1>

93 0 0xffffff7f816ef000 0xca000 0xca000 com.apple.kext.ATI2400Controller (6.0.6) <92 77 9 8 5 4 3 1>

95 0 0xffffff7f813ed000 0x25f000 0x25f000 com.apple.ATIRadeonX2000 (7.0.2) <94 77 9 7 6 5 4 3 1>

100 0 0xffffff7f816d8000 0x12000 0x12000 com.apple.kext.ATIFramebuffer (6.0.6) <92 77 9 8 7 5 4 3 1>

there is one thing i missed, i forgot to replace the ATIRadeonX2000.kext with the old version, so as you see this one is from lion (ver. 7.0.2).

we'll see how it performs. yesterday evening i had 4 gpu freezes in 2 hours w/ the original Lion drivers. once i wasn't able to get to press enter after i typed in my password on the login screen.

well, at that point my mind just blown up.

NOTE TO EVERYONE:

save the original lion kexts to a safe location for the case anything could go wrong.

if you replace the lion ones w/ the 10.6.2 kexts, be sure to remove all extended attributes from them, or OSX will ignore them and you will be sitting next to a blacked out imac. and make sure they are owned by root:wheel

it goes like this:

$ sudo sh

# cd /System/Libraries/Extensions

# chown -R root:wheel ATI*

# xattr -dr ATI*

it is done in a fraction of seconds.

then just wait for 2-3 minutes for kexthelper to automatically rebuild the kernelcaches in the background.

Hello,

I have a 7,1 iMac with with ATI2400. I had many freezes in Snow Leopard so I did the kext replace and used 10.6.7 with 10.6.2 kexts without any problem. Then I decided to upgrade to 10.6.8 and try not to replace kexts. I seemed as OK, I didn't have any freeze for 2 days. But after two days I've got a freeze 2x - 3x per day. I didn't do 10.6.2 replace and I waited for Lion. The scenario with Lion was the same - no freeze for 2 days and then 2 or 3 per day (well Lion saves the state, so after restart I didn't loose all my work).

Yesterday I replaced kexts in Lion with 10.6.2 ones and it seems to work without any problem. The output of kextstat | grep ATI is the same as swmaster posted. I just wonder if it is required to replace com.apple.ATIRadeonX2000 (7.0.2) with older version too?

According to the previous experience it's to early to judge if the kext replace works or not. I will let you know.

I have upgraded to snow leopard 10.6.3 now everything is 1/4 the size, I have iPad stuff on a huge screen,oh how I wish I had left alone can I go back to OS ?

Good info. I'm glad we are starting to see some success. Note..I did not to the last kext you mentioned on my own but my system is working so I assume it keeps that kext from lion. Also..I did make the mistake of not saving the lion kext..ugh! Will they be anywhere on the hard drive for me to find them? If not I may have to get them via email from you. Thanks again for the info. Hope your Mac keeps humming along like mine!

of course, i'll pass it over. i have right now a collection of ati kexts :-)

what's your email?

cjackson@franklinpolice.net. Thanks a lot.

Just an update to my lion experience. I have only experienced freezes when using Apple Motion. Also that program has always cased freezes for me and now they are much less frequent (only two over a whole project as apposed to five or six) I have never personally experienced a freeze anywhere else on the system. In fact there ave been times when the machine has gotten hot and the hard drive has benn full where everything stutters and lags but no freezes.

When I get home today I can check what specific kext files I'm using (with the terminal code mentioned before) if it would be helpful to anyone. Also when I was at the apple store the other day I picked up the kext files on one of the iMacs there. I only got the 2400 ones I think but if someone wants them for some reason I got them (I originally was just picking up the color profiles they had as mine were messed up but I remembered this thread and thought "hey why not")

my 2010 Imac has never had a problem until i installed IOS LION. Now every time i boot it as soon as i click on any application it shows me the beach ball, which remains there until i restart. The only way i can restart is by using the power button as the whole computer is left frozen, cant use the force quit shortcut either. Not sure if this is the same problem as i am not seeing a black screen like others. If anyone can help, would really appreciate it. Really regretting upgrading to LION.

Many Thanks

iMac 24" (8,1) with ATI Radeon HD 2600 Pro on Lion:

Freezes several times today! ... white screen again.

Have now replaced kext files from 10.6.2 on Lion.

Same here, my iMac 8,1 24" 2.8GHz with Radeon 2600 Pro running Lion freezes randomly.

I have just read about this "kext-fix" and will try to figure out how to do it. As soon as I have any news, I will report back.

I have basically the same problem with random freezing. At least with Lion, after reboot, everything goes back to the way I had it before it locked up. I have been following the discussion for quite some time and wish someone would give a step by step discription of how to replace kext files for us non techies. It's all way over my head.

well, i'll try my best...

first of all, you have to grab the 10.6.2 kext files. i have them in case you need them.

depending on your hw, that would be

ATISupport.kext

ATI2400Controller.kext (AT2600Controller.kext)

ATIFramebuffer.kext

ATIRadeonX2000.kext (i did not replace this, however, but my imac is kinda ok, uptime is 3 days 6 hours)

then comes the tricky terminal part. open up a terminal.

first identify, what kexts do you need:

crowley:~ swm$ kextstat | grep ATI

92 2 0xffffff7f813a8000 0x45000 0x45000 com.apple.kext.ATISupport (6.0.6) <77 9 8 7 5 4 3 1>

93 0 0xffffff7f816ef000 0xca000 0xca000 com.apple.kext.ATI2400Controller (6.0.6) <92 77 9 8 5 4 3 1>

95 0 0xffffff7f813ed000 0x25f000 0x25f000 com.apple.ATIRadeonX2000 (7.0.2) <94 77 9 7 6 5 4 3 1>

100 0 0xffffff7f816d8000 0x12000 0x12000 com.apple.kext.ATIFramebuffer (6.0.6) <92 77 9 8 7 5 4 3 1>

mine is an imac7,1 with HD2400xt, so i need ATI2400Controller.kext

$ sudo sh

Password:

sh-3.2#

now you are the root user, total ruler of time and space on your imac :-)

# cd /System/Library/Extensions

# tar czvf /Users/your_username_goes_here/ATI.10.7.0.kexts.tgz ATI*kext

you just made a copy of all your ATI kexts in an archive placed in your home folder.

let's assume, the ATI kexts fot 10.6.2 are located in your home as well

now we will remove the original lion kexts from /System/Library/Extensions

depending on your imac model, you may need to remove ATI2600Controller.kext.

make sure you do not restart your system until you finished this part or have to do

a boot with one of your OSX DVDs as you will have no proper drivers installed.

the best thing would be to close all applications and avoid using mission control, dashboard,

anything that may give you a gpu crash.

make sure you are in /S/L/E

# cd /System/Library/Extensions

remove old kexts

# rm -r ATISupport.kext ATIFramebuffer.kext ATI2400Controller.kext

copy over the files from your homedir to /S/L/E. note the trailing dot (means current working directory)

# cp -R /Users/your_username_goes_here/ATI*\.kext .

change owner to user root, group wheel

# chown -R root:wheel ATISupport.kext ATIFramebuffer.kext ATI2400Controller.kext

remove all extended attributes (safari and mail tends to add on this to note that those files were downloaded from the internet, this may disallow osx to boot those kexts)

# xattr -dr ATISupport.kext ATIFramebuffer.kext ATI2400Controller.kext

basically you're done. you should wait until kexthelper automatically rebuilds the kext caches in the background. that takes 1-3 minutes.

hth.

For those who have a 24" 8,1 Mac with ATI 2600 Pro, use this guide (thanks to CWGuide and KrzysiuTurek) from this thread.

I installed the kext files on Lion and haven't got any freezes so far:

1. *MAKE A BACKUP!* (super important) I used Time Machine and it saved my but as I did it wrong the first time and basically killed my iMac till I restored from my external backup drive.

2. Download and open the .zip file of the old (10.6.2) graphics drivers.(provided by KrzysiuTurek)

3. Download Kext Helper b7.

4. Go to *+Apple Menu>About This Mac>More Info...>Graphics/Display+* and find your graphics card's model. (In my case the ATI,RadeonHD2400)

5. Take ONLY the files titled ATIFramebuffer.kext, ATISupport.kext, and ATI2400Controller.kext *(IF YOU HAVE A DIFFERENT GENERATION OF CARD THEN SELECT THE FILE WITH YOUR CARD'S NUMBER)* and put them on your desktop.

6. Open Kext Helper and drag the three files into the top drop spot.

7. Enter your password in the text entry field.

9. Click *EASY INSTALL*.

The app will do it's thing then ask you to restart the mac. After that it should be smooth sailing (no more freezing 🙂 )

Hope this guide helps! (Also pretty much the same thing has already been posted by KrzysiuTurek. All credit for this fix goes to him (or her) as I only followed his directions)

Thank you very much, both of you and KrzysiuTurek and all the others.

The replacement seemed to have brought no new problems. I will report back soon whether it helped with the crashes.

This fix was working fine for me, then I upgraded to 10.6.8. Computer started crashing - as it had done every time the kext files 'updated' - so I ran this procedure, and my iMac wouldn't boot properly. Got to the apple screen, then a lovely long string of text saying it didn't recognise the replaced .kext files (Sorry, I didn't write down the text).

One reinstall and update of Snow Leopard later, I'm back to where I was. iMac works fine, except when it crashes (sometimes just after startup, sometimes after a few hours of use, it almost always happens if I've woken it up from sleep). Mouse pointer moves, otherwise completely unresponsive.