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

T-squared, I had same issues. See my old posts. My Tech Tool app did not pick up the problem.
The video replacement on my iMac 24" solved the problem. It has now been a month with absolutely no screen freezes. At first, Applecare thought it was a third party software issue. I had to be persistent, until they finally admitted it was their video card. They sent a repair guy out, and he changed the card. The updates just brought on the issue with the faulty video card.

mert wrote:
In your case, did the freezes not occur in 10.6.2, started in 10.6.3 and continued in 10.6.4. And, the hardware issue was not detectable by Apples hardware test suite that comes on the DVDs that ship with it?

Indeed, the system was somewhat stable with 10.6.2. A lot of hardware testing was done by myself and this was once repeated by the AASP. No hardware issue detected by Apple Hardware Test nor by the AASP. But it seemed to be a hardware problem after all.

tommie_c wrote:

mert wrote:
In your case, did the freezes not occur in 10.6.2, started in 10.6.3 and continued in 10.6.4. And, the hardware issue was not detectable by Apples hardware test suite that comes on the DVDs that ship with it?

Indeed, the system was somewhat stable with 10.6.2. A lot of hardware testing was done by myself and this was once repeated by the AASP. No hardware issue detected by Apple Hardware Test nor by the AASP. But it seemed to be a hardware problem after all.

OK - you must be as tired as I am at updating the two related threads.
I'm going to cheat this time 😉 , see here:
http://discussions.apple.com/message.jspa?messageID=12138875#12138875

The freezing problems in this discussion. My iMac exhibits the same behavior as the original post: a dark grey or blue screen nothing works except a power off/on cycle. I have had the hardware tested by Apple and an independent Mac repair hour. Nothing wrong with the hardware. Today Apple suggested reformatting the hard drive and reinstall. So I did, downloaded the latest updates, and we have been running fine for more than 10 hours.
Note: if you have Time Machine the reinstall of docs and apps is wonderfully automatic. The amount of free space on the HD increased by 25%, so there may have been some junk that the ultimate source of the crashes. We shall see...

Just incase this helps anyone, this hasn't happened to me since I stopped using coverflow in iTunes.

i just bought my 27" imac yesterday and while going through the initial setup, it went to a blank screen. the mac is still running and is not in sleep mode, but the screen just went blank. it's been doing this rather continuously. the only way to make the screen come back up is to put the mac in sleep and then wake it back up. i also get a high pitch noise when screen brightness is not equal to 0 or 100. what i found was that the screen will not go blank if the brightness is set to either 0 or 100.... while i've found workarounds for the screen going blank and the high pitch noise, it is rather discouraging that a $1700 machine is so buggy. i hate to say this, but in all my years in IT, i've never come across such an issue in the first couple of days of a new pc................

Message was edited by: dpak379

I have the problem described (white screen, only on/off through power switch available) on my iMac 8,1 (24 inch iMac early 2008). Graphic card is ATI Radeon 2600 Pro. Running 10.6.4.

I erased the hard drive, reinstalled Snow Leopard, had my last Time machine backup over the fresh install, installed the 10.6.2 combo update, and waiting since (4 hours ago). No problems yet.

One thing I had before was Bootcamp, but I did not reinstall it in this new setup. That's a bit stupid, since it will be impossible to identify if the culprit was Bootcamp or something else. But this is my workstation at the office, and I lost enough data already with this problem. I type fast, so I can lose a lot even between 5-minute backups.

I just bought a brand new 27" iMac, I hope I will not have that problem at home too. Will keep you posted.

Update: no more problems on my iMac 24" ealry 2008 since I reverted to 10.6.2

I've been running my brand new iMac 27" for a week without any problems, on 10.6.4.

Weeks after I told you I solved my problem by doing the usual reset SMC trick, I wanted to confirm that I never have had this problem occurring anymore.

I suspect some of us here face real hardware problems, where other like me suffered from an OS "update glitch"...

Yes the SMC reset done it for me, my screen use to freeze on me daily and I haven't had any problems in 2 weeks.

If you havent already I recommend trying it!

Did you tried to connecte a external display ?
(that can be seem amazing but in my case : it's work !)

I've this kind of freeze (black, gray, purple screen) without my external display since many weeks (maybe since Snow Leopard update ... or not). See my post for more detail :
http://discussions.apple.com/thread.jspa?threadID=2594216&start=15&tstart=0

My problem is : I want to sell this iMac 24" (8800GS GPU) but without external display.

More detail :

With the iMac display only, my iMac become very hot, very quickly (+15°C in few minutes) with only desktop to the screen. And the Kernel Panic when I reboot.

My theory is : with the recent SL update & graphic update, "old" 24" iMac have a conflit somewhere and maybe worse : a irreversible hardware damage if Apple remove a temperature security just for run nice iMac (new modele) with ... Valve Steam ? or StarCraft ? But it's just a theory.

But one thing sure : with the last update, some iMac can't shutdown or restart properly (see "delete the the bad preference file" somewhere in the forum).
Like the iMac is very silencer, impossible to see if your iMac is really shutdown or not. In my case, the last month, when I was trying to turn on my iMac : it was already on !! & very hot !

Unacceptable & very dangerous bug from Apple 😟

Skyrickk wrote:
More detail :

With the iMac display only, my iMac become very hot, very quickly (+15°C in few minutes) with only desktop to the screen. And the Kernel Panic when I reboot.

My theory is : with the recent SL update & graphic update, "old" 24" iMac have a conflit somewhere and maybe worse : a irreversible hardware damage if Apple remove a temperature security just for run nice iMac (new modele) with ... Valve Steam ? or StarCraft ? But it's just a theory.

But one thing sure : with the last update, some iMac can't shutdown or restart properly (see "delete the the bad preference file" somewhere in the forum).
Like the iMac is very silencer, impossible to see if your iMac is really shutdown or not. In my case, the last month, when I was trying to turn on my iMac : it was already on !! & very hot !

Unacceptable & very dangerous bug from Apple 😟

Indeed, I think that you are onto something here. Hopefully the hardware damage does not happen, and that 10.6.5 may contain a fix for us !!!

The SMC reset did not help in my case...

same issue here - but you might check this out:

http://classictutorials.com/2010/08/snow-leopard-freezes-or-application-hangs-in -snow-leopard/

Basically check that your system kernel is operating in 64 bit mode, and if not, give it a Terminal kick (sounds a bit fatal, wish they would rename Terminal!) as described in the link. Only tried it yesterday, but everything under Activity Monitor is now working as 64 bit native. Will let you know if it crashes. (or rather my missus crashes it…)

SPB

add me to the list!

same issue here..

see config below.