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

Tazthed wrote:
The funny thing is that Apple has just released an update to Safari 5.0.3 and we can't install it on Snow Leopard 10.6.3! It has to be on 10.6.4 which makes our iMac crash/freeze!

So now it is iLife '11 and Safari 5.0.3 that we can't install......!

can't use the new MobileMe Calendar either.

I had the same problems as the users on this thread. Exact same. I dealt with Apple so much until finally they agreed to replace the graphics card/logic board. I went to the Apple Store a few times as well as had help over the phone and it was never resolved until a tech came out to my house and replaced those parts. Since then I have not had one freeze. The problems seems to be in the hardware in most cases. Luckily I had Apple Care.

I have had no freezes for the last week with the fans ramped up with SMCFanControl. I have a screen shot, but my ISP has changed its freespace settings and I have given up trying to upload it. In any case, there are 3 settings for the minimum fan speed under preferences. I have them set on ODD 1948 rpm (optical disk drive, appears nearest the GPU heatsink, I think); HDD 1200rpm (Hard disk drive); CPU 1554 rpm. Its not too noisy, but you can hear the whirrs.
Running on 10.6.5 with all updates installed. I even reinstalled the last Graphics update, just to make sure. When I'm feeling masochistic I may turn down the fans and see when the freezes kick in, and report. Very many thanks for the Apple problem link, by the way, I just could not find it!

Went back and installed 10.6, did the 10.6.2 Combo update. Installed Pro Tools 9 again. Been surfing in Safari a bit. No freeze yet. Fingers crossed....


-Oex

Clean install btw...

-Oex

I've been having similar stability issue after recently upgraded to Snow Leopard. My iMac is the 2008 model, never had a stability problem while on Leopard. I upgraded to SL recently to 10.6.5, and it will lock up randomly. The occurrence is random, sometimes even while I'm doing nothing, but the iMac will lock up (frozen entirely, mouse not movable, sometimes with a spinning beach ball seconds before, sometimes the iMac's screen just turns black) and my secondary display will show a green screen with some vertical lines (this happens all the time when the iMac locks up). Thing is, since it's random, I don't know how to get proper technical support. I did all the standard troubleshooting methods. I even ran the Techtool diagnostic, and everything is shown to be fine.

First of all sorry for my bad English, I'm writing from Poland

I'm currently testing Simon's solution with SMCFanControl... and in my case it works fine. My fans settings are:

ODD: 1031rpm
HDD: 1200rpm
CPU: 1273rpm

and my mac is running in 64-bit mode.
No freeze from 3 days!! 🙂

I have also tried SMCFanControl. For a while it seemed ok but after a few days I encountered another freeze. Fans were at 1200-1500 RPM each.

@SeSam
Try this setting.
http://img545.imageshack.us/img545/7425/screenshot20101123at426.png

I haven't experienced a freeze for 6 days, which was impossible before.
I updated 10.6.5 right after Apple released and as expected the freeze happened again. I CAN not understand why my system lock up while just surfing the web on Safari.
So I installed SMCfancontrol again.

it won't work. I've had this problem since 2007-08 and my fan rpms are at 3600. You are lucky your system lasted this long.

I have the same problem with my iMac 21,5" 10,1.
Just from when i bought it, March 2010, i had experienced many times freezing.
All the time when i surfed the web with Safari. In the first time i believe that Flash plug-in was the problem, but now i'm not sure about this.
This mac is placed in my room and i usually work for just 2 hours 3/4 days at week. But when i work with iMovie for 3/4 hours no kynd of problem, when i'm using Safari ( and just one time with Chrome) freeze happens.
I made all the test with techtool deluxe (except surface scan that i try to launch in this week-end) and no kynd of problem.
After the surface test i will call Apple in Italy ( i bought an Apple's care program) and try to understand if something.
Besides this, i have a question for all of you that have this problem: are you connected to the internet via Wifi airport or Ethernet Cable ?
Bye
Matteo

Couple of minutes ago I try to reply to this post, and boom... - another black screen.
But this time my iMac is connected to the external HDD

Tommorow I will go back to 10.6.2.

Message was edited by: KrzysiuTurek

It has nothing to do with WiFi or Ethernet Cable.

It is probably the graphics card. Apple just doesn't want to solve this issue even though a lot of people are complaining!

The problem is the location of the graphics card inside some iMacs. It happens that the CPU seams to be too close to the Graphics Card in the 2007 24" iMac (mine). The heat causes freezing and funny elements showing up. The solution I found (like many) was to bump the fans to the max by software (I use "Fan Control").

But after 10.6.(I don't know exactly) my system started to crash again, specially when using Safari (?)
My guess is that Apple is pushing the GPU use forward with the new versions of their OS and softwares. This is probably heating things up... And here in Brazil the whether doesn't help much 😟

Is there any chance for us to get organized and transform this in a "GPUGATE" or "FREEZEGATE" for the lack of a better name? Any suggestions??

Repeating what someone already said, please do a formal report to Apple:

http://www.apple.com/feedback/macosx.html

I'm doing mine right now...