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

I have been getting freezes since 10.6.0, and have been hoping that every update Apple has put out would fix the problem. Similar to other users, I get squares on (both of) my displays where the screen does not refresh properly. Additionally when using some applications (such as Finder, Safari or iTunes), the screen will not refresh properly when scrolling or closing tabs / windows. Computer freezing doesn't seem to be an issue with disk space or the main system RAM - I know as it has frozen while I have the activity monitor open at the same time as watching TV on the iMac. A hard power off and cold restart is the only way to fix this freeze, as the keyboard does not respond and the mouse still moves around but is unable to activate any menus.

For DazzaG, you are not alone. My first freezes came last night while updating my blog using Google Chrome. I had one freeze that was identical to the image you posted on picasa. Then I had another one that was a photonegative of the first, screen all white with similar contrasting grey stripes. In both cases, the freeze occurred the instant I scrolled the page in Google Chrome with my Magic Mouse.

I don't have an idea at the moment, just wanted to see if these scenarios might match any of the other freeze scenarios.

Hardware Overview:

Model Name: iMac
Model Identifier: iMac8,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.8 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 6 MB
Memory: 2 GB
Bus Speed: 1.07 GHz
Boot ROM Version: IM81.00C1.B00
SMC Version (system): 1.30f1

ATI Radeon HD 2600 Pro:

Chipset Model: ATI Radeon HD 2600 Pro
Type: GPU
Bus: PCIe
PCIe Lane Width: x16
VRAM (Total): 256 MB
Vendor: ATI (0x1002)
Device ID: 0x9583
Revision ID: 0x0000
ROM Revision: 113-B2250L-259
EFI Driver Version: 01.00.259
Displays:
iMac:
Resolution: 1920 x 1200
Pixel Depth: 32-Bit Color (ARGB8888)
Main Display: Yes
Mirror: Off
Online: Yes
Built-In: Yes
Display Connector:
Status: No Display Connected

Just chiming in with my 'Me Too'. Since updating my iMac to 10.6.3, I will either get a frozen state unresponsivr to keybard or mouse clicks, or a black screen after some time of letting it run.

I've found out however that the Mac is still responsive on the back end, as determined by hearing my time machine drive spin up at it's schedualed time, as well as being able to SSH into it from the coffee shop I was chilling at all evening yesterday, but later noticed it had frozen hours before per the clock status.

Your mileage may vary.

Its my current route as to backing up some of the things time machine misses.

I've had the same freezing problems with my 15" Macbook Pro (2007 model). After a few hours the system would freeze and holding down the power button would be the only remedy. Reinstalling the system with Time Machine and upgrading to 10.6.3 (build 10D573) did not work. Reinstalling the system with Time Machine and downloading and installing the old 10.6.2 combo update did solve the freezing problems. However, Apple recently (12 April 2010) released an 10.6.3 v1.1 Update (build 10D578). I downloaded ( http://support.apple.com/kb/DL1017 ) this latest update and it DOES solve my freezing problems. My Macbook pro runs great now. I hope this information is useful.

Another "me too" post, I'm afraid. My freezing issues are many and varied. Sometimes the mouse will move around, but nothing responds (not even the dock). Lately, though, it's been the screen that just cuts out completely. If it doesn't go to black, it usually it gets some weird artsy design on it. Green stripes, black and white stripes; just this morning it was this funky white-with-multicoloured-dots that shimmered. I have to admit to being curious each time which one it will look like.

I downloaded the v1.1 update yesterday, but it doesn't seem to have helped. In fact it happened twice in a row right after I installed it. I have one of the first aluminum Macs from 2007, when they came still running on Tiger. Maybe it's just giving up the ghost?

Has anyone with an active warranty tried contacting Apple? I'd do it, but mine's run out, including AppleCare. I doubt they'd listen to me.

It seems that our problems are not the same. I'm sorry to hear that the 10.6.3 v1.1 (build 10D578) update did not solve your problems. My Macbook pro is still in warranty and I did call Apple twice before the 10.6.3. v1.1 (10D578) fixed my problems. I got the typical Apple support response. They have heard of similar cases, and their software engineers keep gathering information and will release an update when they feel it's necessary but the support person knows nothing more than what you get from Googling the problem. Depending on how serious your problem is (as in: how many others have the same problem) they may or may not fix it fast. Unfortunately, you will probably have to wait for 10.6.4, which will probably take several months up to half a year, typically. I recommend that you don't hold your breath, reinstall Snow Leopard with Time Machine and then install the 10.6.2 combo ( http://support.apple.com/kb/dl959 ). That worked well for me in the meantime. Good luck!

Just in (14 April 2010), Apple released Security Update 2010-003. After installing the 10.6.3 v1.1 (10D578) combo update (see earlier posts) get the Security Update 2010-003 via Software Update. Perhaps you are lucky and hopefully it will fix your problems.

My freezing issues are exactly same as yours mouse works but can't click anything and it can go into sleep with power button but wakeup with blue screen with nothing on it.

Also I observed *weird artsy design on it. Green stripes, black and white stripes* once.

Ok , I experience the same problem since the update to 10.6.3. System freezing up totally (except mouse movement! - when visible) Sometimes the screen is visible, sometimes it blanks.
Somehow I am glad I found this thread, I tried about anything and was worrying about my hardware. Hopefully there will be a solution soon.

Modelnaam: iMac
Modelaanduiding: iMac8,1
Processornaam: Intel Core 2 Duo
Processorsnelheid: 2,66 GHz
Aantal processors: 1
Totaal aantal cores: 2
L2-cache: 6 MB
Geheugen: 4 GB
Bussnelheid: 1,07 GHz
Opstart-ROM-versie: IM81.00C1.B00
SMC-versie (systeem): 1.29f1
Serienummer (systeem): W88098JTZE3
Hardware-UUID: C5619DC4-DF3E-5C8D-BA6A-38BE836ECF82

If you are having this problem, what graphics card do you have?

To make sure Apple actually know about your problem, submit a bug report.
http://www.apple.com/feedback/macosx.html

Thx, did that

I'm in the same boat. 24" 2.8 Ghz iMac with 4GB RAM and the Radeon 2600 Pro.

It will just freeze randomly with a hard restart being the only solution. This happens multiple times per day and has only started occurring since I installed 10.6.3. It's completely unpredictable and I can't get any meaningful work done reliably.

I have never been so frustrated with my mac in my life.

Hi, ok after a lot of searching I found some posts about a possible solution. I have tried it myself and since then have been running my mac for about 6 hours without a crash. Since the last security update it freezed about every hour, so it seems promising enough...
Download the Mac OS X 10.6.3 v1.1 combo update and install it, that seems to do the trick (for me at last) I know I am very soon with my conclusions but I know how frustrating this is (the first time ever I did NOT like my mac anymore) so I wanted to let you know asap.
Succes!

Hi, I know that I am kinda new around here but I have been using Macs for a little over 10 years now. I noticed a similar problem with my white 24" C2D iMac a while back. After some digging I found that the graphics card overheating could have been causing it. Doing 2 things solved it for me;

1. I installed SMC Fan Control and bumped up the speed of the fans within the system.

2. Opened the system and using a can of compressed air cleaned out the fan which had quite a bit of dust accumulated on it.

Can't say if this is related and most of the posters seem to think it's related to the update but it may be worth looking into.

Shaheed

Sorry to have to say this: After the combo update it worked fine for hours and hours (and there is a difference between the combo and installing all updates from Update, the build number confirms that!)
But: today, after just two minutes of working it happened again. This time my screen was entirely black. Which should exclude the overheating option too.