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

I think we have success, on the install, at least. My version numbers are now what they should be. I think I know what I did wrong the first time.

Now it's wait and see if the problem is fixed. Thanks for your help.

@Marno49, glad to see you may have success! Thanks geychaner for the clarifications. ANd thanks for this forum! First time I ever used it, and it was well worth it. Glad to see it can help others as well. Now if Apple or ATI would just FIX the problem!

Marno49 wrote:

I think we have success, on the install, at least. My version numbers are now what they should be. I think I know what I did wrong the first time.

Now it's wait and see if the problem is fixed. Thanks for your help.

Hi Marno49,

could you explain how you did, please? What did you wrong the first time?

I've got the same problem as you: I can't replace kext files properly.

I have read and tried the different indications whith no success 😟 :

kextstat | grep ATI

77 2 0x14a5000 0x12e000 0x12d000 com.apple.kext.ATISupport (6.3.6) <76 14 13 7 5 4 3 1>

78 0 0x15d3000 0x2a000 0x29000 com.apple.kext.ATI2400Controller (6.3.6) <77 76 14 13 5 4 3 1>

81 0 0x96f000 0x247000 0x246000 com.apple.ATIRadeonX2000 (6.3.6) <80 76 14 7 6 5 4 3 1>

103 0 0x16bf000 0x13000 0x12000 com.apple.kext.ATIFramebuffer (6.3.6) <77 76 14 13 7 5 4 3 1>

.

I used the instructions on page 28 of this thread, but I went wrong at step 5, where it says "Take the files........ and put them on your desktop." I thought it meant take the bad files from my system directory, so those are the ones I put on the desktop, and those are the ones the installer used the first time. So of course, I was only replacing the problem files with another copy of the problem files. I subsequently figured out that I was supposed to take these files from the .zip file of the old drivers I downloaded in step 2. When I did it that way I ended up with the right versions. Makes sense, of course, but because it wasn't spelled out, and not knowing what a "kext installer" did, I didn't realise my mistake at the time.

Don't know if this helps you (and I don't even know yet if the problem is fixed for me, as it has only been 2 days, but no freeze so far). Good luck.

Thank you Marno49 for your quick response.

I'm not doing the same mistake so I continued finding out what's the problem.

Although I had already changed the corresponding kext, I have seen (System profile) that the system had used a copy of them and not those of the 10.6.2.

So I deleted the copy and re-install the "old" kext (10.6.2, KrzysiuTurek "method"), but I get always a nice "kernel panic" when the computer starts. I tried to force 64bit as recommended by Harkaitz (in fact I had it so), but still gives kernel error.

I keep trying and, of course, it is accepted suggestions 😉

Well, it appears (may be too soon to say) that a very similar issue as the OP has been fixed by subbing the kext files as described in this thread.

I have a mid-07 aluminum iMac 20". Since about March of this year I've been getting random freeze-ups. Mouse would move but could not click on anything. Only way out was by forced shutdown. I was associating the freezes with either waking from sleep, Chrome, or Parallels. When I updated to Lion, freezing continued, and actually got worse - kernel panics became almost a daily occurrence.

I gave the hard drive an enima and the problems persisted. I went to a Genius who decided it was a bad hard drive - to be fair the hard drive was failing with 57 reallocated sectors. So I did some surgery and put a new hard drive in (which, granted had one reallocated sector). Reinstalled Snow Leopard, used it for a day, then updated, and then upgraded once again to Lion. Within a day I had a freeze.

Yesterday I had a freeze, rebooted, and was presented with a freeze-up within a minute of reaching the desktop. So I tried replacing the files outlined, and since then I've had no freeze-ups at all.

I'll give it a couple more days and if all goes well I'll post again.

I answer myself 😉

First the machine:

iMac 7.1 2Ghz, 2GB, ATI HD2400

the problem, you know:

GPU crash -> iMac screen freezes 😟

I have read previous post again and I think for my iMac the solution is (SnowLeopard not Lion):

Downgrade to SL 10.6.7 and use kext from 10.6.2 (Harkaitz dixit)

because kext 10.6.2 in SL 10.6.8 only works in 64bits mode but my iMac can't

I'm right?

I don't think that's what the post says, but apparently you should try reading more of the posts, since I stated more than once that I have the same machine as you and I have Lion with the 10.6.2 kexts working fine. Good luck.

OK I've been 3 days without a freeze. I think the ATi kext file was definitely the culprit. I have noticed the performace of the older driver is noticibly worse than the latest from ATi, but I'd rather have stability than performance.

The solution described is for Snow Leopard.

In my iMac with Lion seems to work in 64bit, so you can use the 10.6.2 kext, but iMac 7.1 with SL, curiously, does not accept 64bit mode.

Thanks anyway richard.s.hall, it's good to know that I can update to Lion my iMac.

they are 64bit-aware. you can run a full 64bit lion with them 10.6.2 kexts. see below.

by the way, even with the 10.6.2 kexts there is a way to get the GPU down to its knees:

run a game that requires 3d support. i did it with heroes of might and magic 5 for mac.

it's pretty deterministic. you start the game, it's fine until you start playing a scenario.

then the good old gpu debug kicks in, and you have to restart your imac from a remote ssh

session.

it must be some kind of opengl feature behind the scenes, which is requiring the faulty part of

the gpu. the same game however runs w/o any glitches on my wife's imac, which is the very

same model (imac7,1) with the very same specs and softwares installed, but w/o the 10.6.2

kexts, as they are not needed. i have to confess, her mac is a bit newer (2 months younger than

mine), however down to the very bits it's pretty much the same (same cpu, same gpu, same firmwares).

so behind all this cr#p there must be some part of the gpu doing it wrong... and we were unlucky.

I had the same problem with my computer. I used the method described and I got the gray screen. Fredmania mentioned that he changed the permissions on the kext files. How do you do that?

If I'm not wrong the kernel panic (gray screen) is not due to permissions, but by not being in 64-bit

The way to do it here: https://discussions.apple.com/thread/2384136?start=555&tstart=0

But keep in mind if your iMac can: http://support.apple.com/kb/HT3770

I used the kext rollback others talked about but consistently had a kernel panic (grey screen) when I applied the "fix" to a 10.6.8 instal. I could never get past this. But, since then I've successfully applied this fix to 10.6.6 and to 10.7.2. I didn't have to do anything with permissions nor with 64-bit mode since my machine's CPU doesn't support 64-bit. (It's a mid 2007, 20.1" Core 2 Duo machine with ATI 2400HD graphics.)

I upgraded to 10.6.6 so I can get to the App store to get Lion. Thanks to all for sharing this info.