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

there was one thing unclear about siputility:

after running siputility you get 2 option buttons: "set" and "exit".

when i hit the set button i am asked to type my password to proceed. after that this window appears:

so i just hit exit. everything runs smoothly though..

For davidefrombruino or anyone who had used the SIPUtility, and noted that the kext settings seemed to reset from what you had set with SIPUtility, can you confirm if the kext settings continue to reset? Or has that element of the problem resolved itself?

I also am wondering if the reset of kext files that some users experienced may have happened after an OS X El Capitan version patch, or some similar system upgrade. Perhaps that explains what happened? Thanks again.

I had a freeze about on Oct 30 after installing El Capitan and the fix on Oct 19. When I booted back up I saw I did not have the right kext fix files, the AMD ones were there instead. I thought I had somehow not done the fix install properly even though I had checked the right files were there at the time. Although it also occurred to me that it might have come from some tweaking they did to El Capitan, so maybe it really was that, as you suggest . Reinstalled the fix, but had another freeze Nov 15. This time the right files were there when I came back up, and has not frozen in the 3 days since.

However, I have a big problem with El Capitan running really slow most of the time. I have 4 GB of RAM, and most of the time the system is using over 3.5 GB. All I do is Mail, Safari, Pages, and iTunes, no fancy big programs. kernel_task is the biggest user, usually about .5 GB. When I looked to see if there is any way to deal with this I found several sources recommending to remove a certain file as per the Badgermonkey instructions below. Interestingly, it is a kext file which is identified as the culprit. I don't know enough about any of this stuff, but it makes me wonder if our kext fix is contributing to my problem. It also makes me reluctant to try this.

Or maybe 4 GB just not enough to run El Capitan properly? And I should just give up on this machine and get a new one? I'd be interested in any comments or thoughts on this from anyone out there.

BadgermonkeyOct 28, 2015 12:05 PM Re: Problem with Kernel Task - El Capitan
Re: Problem with Kernel Task - El Capitanin response to amico96Solved

I had this issue with a previous upgrade and this fix worked great. However, in El Cap this is a protected system file. In order to delete it you need to:

0. Reboot into recovery mode (Command + R on boot prior to startup chime), select Utilities/Terminal, csrutil disable <Enter> (repeat process, use csrutil enable after removing the file), reboot.

1. Go to About this mac under the apple in the upper left and click on More info

2. Click on system report

3. make a note of what it says after Model Identifier (MacBookPro8,2 is mine).

4. From the Root drive (not home folder): – System Library – Extensions – IOPlatformPluginFamily.kext (alt-click/View Contents) – Plugins – ACPI_SMC_PlatformPlugin.kext – View Contents – Resources -– find the name from step 3 and move it to a folder that you can find again if needed.

3. Restart and you’re done (other than enabling SIP).

I can use my Mac again!

Late 2011 15", i7 2.2, 16GB 1333, 1TB hybrid drive, OSX 10.11.1

Up to 10.11.2 on a 20-inch, mid-2007 iMac. The latest update left the three relevant, previously installed ATI extensions in place, so I just had to trash their AMD equivalents, tell El Capitan to load unsigned kexts & fix the permissions of the old ATI ones. My ageing machine no longer works particularly quickly, but it does still work! Thanks again, all those who've helped with this (and I don't mean you, Cook, TD). – Dave M

Thank you to everyone who posted about this problem. I've been trying to get to the bottom of it for two or three years, and finally did so thanks to this thread.

I'm now running 10.11.2 on a 2007 20" iMac successfully after following davidefrombruino's steps.

I omitted step #6 without issue, and even turned System Integrity Protection back on.

This is a general message about a notable improvement seemingly introduced with 10.11.2,

(at least for the mid-2007 iMac 20" (ATI 2400) I've been updating using all the suggestions here).

That is, for the very first time since 10.6.2, H.264 video runs with hardware acceleration.

What I observed very frustratingly, including resorting to using Windows 7/10 drivers,

is that even though ATI/AMD driver substitution fixed freezes and enabled a certain type

of hardware acceleration, my machine could never spin 720p or 1080p videos right,

using either QuickTime 7 or QuickTime X.

I was about to give up and think that Apple would never fix the interfaces for this behavior,

but it works now. Now, with the hacks, Apple can finally say that this lowly machine (now made officially

vintage/obsolete on their lists) can run almost on par with 10.6.2.

Hi all. 20" iMac mid 2007 - ATI Radeon HD 2400 XT. 3gb Ram. Currently running 10.8.5

I have posted to the PARENT of this thread several years ago and have followed it for several years in the past, and have done Kext fixes throughout the years with the help of KrzysiuTurek's PATCH FIX.

But now, almost dealing with a machine that is about 9 years old, I have no desire to replace it and would like to bring it's functionality back before I go nuts.

I am tired and confused (and old now too), so there is no way for me to get back into this and figure out all that I have missed. I am hoping that retiarius and PSUTyler would be able to point me to clear and concise direction to upgrade to El Capitan and put all this KEXT / Radeon issues behind me. You guys mention instructions by davidefrombruino but I can not seem to locate them anywhere, I know this post and maybe many others have spawned from the one I was involved with that has something like 119 pages now with same title as this one.

Typically I have those video freezes where the mouse will move but everything else is frozen and have to do a hard shutdown and restart. I also get a lot of lock ups when booting up.

THANK YOU IN ADVANCE, I would love to put this PITA behind me.

Mike D.

Link to this post

Thank you.

I will need to swallow a "Brave" pill before moving forward. I appreciate everyone on this for years !

Mike

Unfortunately, it looks like this fix may not work on 8.1 models, for which the firmware update actually works…

As far as I'm concerned, I've tested this method on a 2008 24" iMac, which I've replaced with a Mini.

I was not worried to try this "make or break" fix since I consider the iMac to be unsellable as is – I mean, interested buyers are super pleased to discover you must use the kext fix after every system update (OS X + security), especially as they tend to buy one of those old Macs because they stand the test of time. Hands up – Oh really?

Flashing took quite some time but… it ran as expected but updated absolutely nothing, it just re-flashed the same version of the ROM (113-B2250L-259). It actually feels quite weird ATIFlash moved forward instead of displaying a message telling you don't need to do it (as expected for the bootcd with the old rom).

I had just forgotten the firmware update applied and that I ran it at the time it was released. How silly of me.

By the way, the code provided for the bootcd config and autoexec files absolutely failed on this model. Twice. I was sure there was no error in there so I had to find an alternative way to get a rescue CD – sorry, it was weeks ago and I don't remember how.

Also, I feel like using a Linux Live CD/DVD (like Ubuntu for instance) + Linux ATIFlash and the dumped rom would be a lot easier for a lot of people willing to take the jump.

Result: nothing. Freezes, again and again and again.

Anyways, since the 10.6.2 kexts were creating UI problems in Yosemite, especially in Settings (like weird dimensions for some panels, rendering them unclickable hence unusable), I decided to update to El Capitan to check whether this re-flash could somehow have any meaningful impact with El Cap's AMD kexts.

The update just failed. To sum things up, OS X hung after login and would not move forward following the install. It was not even possible to use the Recovery Partition to re-install El Capitan…

As a consequence, I took the nuclear road and erased the iMac HD using a Mavericks install on an external HD – those external installs have proved insanely useful over the years for me so it may be a good idea to create one. Reinstalling from a Time Machine backup was out of question as I didn't want El Cap to deal with the "kext fix legacy" – I didn't even import apps + documents from TM afterwards but I guess that won't be a problem if you want to do it.

I grabbed Snow Leopard's install CD, updated to 10.6.8 then updated directly to El Capitan (10.11.3). Needless to say a fresh install of OS X felt really really fast and responsive. And it felt very stable too!

However, I can't currently confirm re-flashing + fresh install did the trick because it's winter and I've experienced those freezes mainly in summer – which is the reason why I first went with SMCFanControl instead of 10.6.2 kexts.

I have good hope freezes are behind and I'm wondering if updating Snow Leopard to 10.6.8 with the newest ROM is not a key to solving this problem.

[Sorry, looks like I can't edit my previous post.]

Also, when investigating the “GC flashing fix” provided by JoePan, I actually discovered this thread: http://hints.macworld.com/article.php?story=20100117025218440

To sum things up, it appears iMac graphic problems are nothing new and once again, it seemed linked to overheating (hence the advice of using smcFanControl). The OP actually drilled holes in the back of his late 2006 iMac. He drilled holes!

Interestingly, the latest post in this thread mentions Quartz: disabling it if the GC was damaged seems to help those previous models keep on going. So my question is quite simple: has anyone tried using his iMac in safe mode – in which Quartz is disabled – for a few days, kext fix unapplied?

The problem being Quartz related kind of makes sense to me after all. Indeed, I remember having an insane amount of freezes while using Pixelmator before applying the kext fix. Now, this app is making intensive use of Quartz Composer for effects.

Edit: And… some Late 2009 iMac users have been experiencing this very same bug with Mavericks and Yosemite.

See http://www.pauloamgomes.net/blog/fix-weird-os-x-freeze-imacs-late-2009 and http://apple.stackexchange.com/questions/204348/imac-freezes-complete-except-mou se-pointer-what-can-i-do

This particular post is interesting:

I had this problem as well, it turns out that migrating from a prior version was the problem, specifically kernel extensions that used to worked now "sorta" worked until they didn't.

Using Lingon (see the Apple Store), it was possible turn on and off various services to locate the problematic one(s). Using Onyx it was possible to clear out the kernel caches.

For me it was some historic SnapZPro extensions that needed updating.

Since I've not experienced any freeze since doing a fresh install of El Capitan, I can relate to that.

I was able to update my 7,1 iMac to 10.11.3 with the 10.6.2 kext fix. Everything looks stable so far. Thanks to davidefrombruino's instructions:

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

My only comment on his instruction would be that 'command -R' is recovery mode, not safe mode. That threw a novice like me for a loop. It also wasn't obvious that once in recovery mode there's a way to get to terminal. I had to look that up as well.

I can't believe Apple can't get someone to do a quick diff of 10.6.2 vs 10.6.3 kext to see what exactly broke the driver. It would probably take less than a day to figure out the difference and make the appropriate patch in El Capitan update.

>I can't believe Apple can't get someone to do a quick diff of 10.6.2 vs 10.6.3 kext to see what exactly broke the driver. It would probably take less than a day to figure out the difference and make the appropriate patch in El Capitan update.

My favorite explanation of the driver bug is the "errata" theory, as explicated on this forum many moons ago:

jaycee1980Jun 26, 2012 6:43 PM

in response to BatmanNewsChris

It wont ever get fixed. Apple's official line on things is that lockups on ATI 2400/2600 hardware is caused by a faulty GPU - even when it can be demonstrated that the hardware is fine and the problem is solely software.

My personal reasoning on this is that on older ATI 2400/2600, there is a firmware or hardware errata that is worked around by the drivers. For some reason, the fix for this errata has been removed from the newer drivers. Newer hardware revisions are fine - hence why replacing GPU fixes the problem.

I'll note that under Windows I had bluescreens and "display driver resets" for a while using ATI's official Catalyst drivers. At some point, they resolved the problem. This tells me that ATI may have made a mistake and later corrected it, the mistake was passed onto Apple who have not corrected it.

_______

Of course Apple can say that these iMacs are not just "vintage" but "obsolete", so therefore are undeserving of support.

However Apple should be accountable to uphold the current advertisement that iMac7,1 can run El Capitan, although it's

done unacceptably via either "safe mode", or with these hacks.

FYI, 10.11.4 official is fixed by the kext replacement procedure, as the latest release still freezes fairly quickly without the old kexts.

All iMac with video cards from ATI / AMD have overheating problems. For 6 years I had problems with artifacts and crashing that I had to fix by turning the power off button.

My iMac 27 with VGA Ati HD4850 had blocking problems just looking at a website or using pages. First small artifacts, small problems in view of the desktop icons up to 5 lines RGB (red and green) ... since Apple considers the iMac 27 end of 2009 vintage, I did change the video card, the genius Apple did not want nenahce change me when it was covered by Apple Care, an authorized center fielder. Now I have no more problems.

I, too, can confirm that the 10.6.2 kext replacement works for 10.11.4. I have been doing this for years on my 7,1 iMac without any issues, but with this last update the kext replacement seems to have a new side effect that I've never experienced before. I can no longer put my computer to sleep, whether through the keyboard shortcut, the power button, the apple menu, or a schedule. If I switch back to the kext files installed with 10.11.4, sleep works fine. So, there seems to be something new in 10.11.4 that conflicts with the 10.6.2 kext files that breaks the sleep mode. It's annoying, but better than a frozen screen. I just make sure to shut down the computer each time. Has any one else experienced this?