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

I did the El Capitan update today and followed the instructions posted by davidefrombruino, but with the ATI2600controller.kext, because I have the 24" iMac from 2008.

So far no freezes and everything works fine.

Thanks for the guide davidefrombruino !

davidefrombruino for president!!

iMac Early 2008 and Ati 2600Pro now works fine 🙂

I did a clean install last night and my system ran well all night, with both monitors working and 10.11 Kext loaded.

Tonight though I had a couple of graphic crashes whilst trying to restore my documents and setup etc.

I then did the 10.6.2 KEXT update following the same procedure as last time, which went much smoother this time with no graphics crashes occurring during the procedure. However I again got the same problem with my second monitor failing to start after rebooting from the recovery mode after enabling the SIP using "csrutil enable". Both monitors were working fine during the kext update and in recovery mode just prior to the reboot.

On restarting El Capitan my second monitor failed to enable and stayed off but this time rather than disabling SIP again in the recovery mode. I decided to have another try at using the SIPUtility and set the change again before rebooting. This time when my system came up, the second monitor was back working again 🙂

I sure I did this as well the other day, but this time its definitely worked ok and both monitors are back up and running.

24" iMac 2008. The kext fix still works great. No freezes for many days now. But I regret updating to El Capitan. The performance is very SLOW!

It is slower than Yosemite. Hope that an update can fix it.

Tazthed wrote:

24" iMac 2008. The kext fix still works great. No freezes for many days now. But I regret updating to El Capitan. The performance is very SLOW!

It is slower than Yosemite. Hope that an update can fix it.

This thread is way too long to diagnose your performance issue.

You should start a new thread, and post the output from EtreCheck

<https://discussions.apple.com/docs/DOC-6174>

Applications -> Utilities -> Activity Monitor to see if something is hogging the CPU, the Network, or memory.

You should also look at your Applications -> Utilities -> Console logs to see if there is a frequently repeating entry that might indicate a process starting, dying, starting, dying, starting, dying, ... These events do not show up on Activity Monitor as they do not live long enough to really register.

Put all this information in a new thread in the El Capitan forum

I've been waiting for an update to the 27" 5K iMac but am very very wary of buying another dodgy Apple product given the history I have had with the current iMacs and the lack of support on this video issue by Apple. I was really annoyed to see the 5K iMacs still have AMD (ATI) videos -- BANGS HEAD ON WALL and CRIES.. I was dreaming... hoping that they might switch to NVidia.

I'm really not sure I want to risk it again with a £2,000 GBP purchase 😟 for what might be the same old $$$$ from Apple and AMD. I really have lost faith and all trust in Apple hardware 😟

This guide works ! My mac is stable after 3 days, first time after years.

You wrote a clear and easy guide to solve the problem, but I am very angry with Apple!

This thread started about 5 yrs ago, lot of user with iMac 2007/2008 in real trouble and Apple didn't move a finger..

It was clearly the switch from ATI to AMD kext (drivers) the problem, they simple had to release an patch/update for those machines affected.

Unbelievable.. how many restart I did with the iMac frozen !!!!!!

Update: After a few weeks of stable operation, during a reboot, the kext in question have not been loaded (mysteriously).

I used SIPUtility as described in step 6 and now everything works as before.

Dear Davide,

This is a strange outcome, as it suggests that the fix does not necessarily hold. But that seems unlikely. Is it possible that El Capitan auto-updated to something before the point release without being apparent that it was happening?

Thanks.

Tony

Just happened to me, very strange, we have to solve.

We are close to see what will happen once updated to 10.11.1 too...

While not an ideal solution, would it work just to leave System Integrity Protection (SIP) off completely, rather than use the SIPUtility to selectively unprotect the kexts? Could it be that El Capital is "healing" itself from the SIPUtility tweaks (i.e., returning them to default state)? And if so, could turning off SIP altogether allow the old (i.e., non-crashing) kexts to load consistently?

Also, for those experiencing this problem, I am assuming you removed the new (i.e., crashing) texts completely from your system so that the OS cannot find (and load) them, correct? Or is it that the OS is not loading either set of kexts (because it refuses to load the old and cannot find the new), and you are getting some kind of generic graphics on your screen upon reboot? Thanks. - Tony

It could be a good solution, for the moment I just can say that updating to 10.11.1 reverts everything back to AMD kext !!!!!!

yesterday i updated my iMac (24-inch, Early 2008) to 10.11.1, and for the first time since 10.6.3 my computer didn't freeze during or after start up.

to test stability after installing the new update i started playing battlefield 2 and everything went well, no freezes at all!

before this update, on 10.11 battlefield crashed to desktop while loading. this might have been happening because of the new fix...

since 10.6.3 the computer would freeze right away after i started the game. now everything seems to be just fine.

i am amazed! could it be that apple finally addressed the issue after 5 years of troubleshooting?

Thank you for sharing your experience with this group. However, my expectation is in a few days your iMac will start crashing again. Sometimes it happens right away and other times it takes a few days. But without the kext fix, if it was cashing before, it will start crashing again. You just have to be patient....

Maybe I'm wrong and will be happy to be proven so. (Not putting money on it, though.)

your expectation was right, imac froze right away after startup this morning.

never before my computer lasted this long after applying an update, and a game like bf2 would freeze my imac within minutes.

so again i applied the fix suggested by davidefrombruino. my imac froze another 3 times while trying to apply the fix.

now everything is back to normal again and i even can play bf2 without crashing or freezing.

thanks a lot for all the help every time!!