System Freezes Randomly after 10.6.3 Update

Since my last post on Aug 22, Applecare has replaced my video card and logic board. It has been about four weeks and so far so good. No finder freezes and no screen black-out or pixel stripped screens.

So, based on my experience, this is definitely a hardware issue. Why OS updates beyond 10.6.2 cause this problem is still a mystery, but I also confirmed that downgrading back to 10.6.2 made the problems go away. But after I returned to 10.6.4 the screen freezes returned. Apple Support had me do an erase and reinstall, with no 3rd party software, and that seemed to eliminate the screen freezes, but the blackouts and pixeled screens continued. When I emailed a photo of a pixeled screen to Apple Support, the advisor immediately determined it was a hardware issue and sent me to the local Apple Store. The Apple store genius was also convinced by the photo of the screen and did not even bother to do any diagnostics, and instead, just ordered the graphics card and logic board. After the parts arrived, they had the iMac fixed the next day.

Hope my experience is helpful to somebody out there with these same problems.

DKisling wrote:
Why OS updates beyond 10.6.2 cause this problem is still a mystery …

Any change to any component file of the OS potentially changes the timing & order of various routines the computer executes. Because this can also change the memory, registers, or other hardware components that executes those routines, & because some hardware defects in those items only show up in combination with certain data patterns in other items, it should not be too surprising that an OS update can reveal hardware defects that are otherwise hard to find.

RC-R

I have reinstalled the OS, both clean and archive. Still had freezes with no 3rd party apps installed. I went back to 10.6.2. No problems. When 10.6.4 came out I went with it and freezes came back. I've done disk utility a hundred times, AHT and no problems found. Apple store found nothing either.

My wife and I, in the past, put it to sleep when done using the computer. If we log out, instead, and let computer go to sleep by itself, puter seems to be stable. Kinda strange.

I've spent months trying to identify this problem with every check I can think of and a lot of internet searching. I'm amazed I narrowed it down to waking from sleep. At least, I can do something to stop the freezing. I still tend to think it is a software problem inherent with 10.6.3 and above since nothing else wrong can be found. I'm also guessing it is a problem with certain Macs and not others. The software doesn't play nicely with every OS and its hardware configurations. I have an early 7,1 Mac for what it is worth.

Thanks for your reply

RM

I have one other question. In the past I've wondered if Snow Leopard is installing correctly from my disk. Somewhere in these forums, someone mentioned that as they install Snow Leopard it begins its thing. Somewhere in the middle of the install, it goes into safe mode (northern lights desktop) and finishes the installation. Others in the forums didn't think that was normal. This install behavior has happened to me with all 3 or 4 installs I've done. First time I installed Snow Leopard, I thought "well, thats different. Never seen that before?" Seems the disk should put the computer into safe mode from the beginning to the end.

Can anyone confirm this or am I imagining things?

RM

Hi,

I found some info in another thread that claims to trace a similar problem to sleeping hard drives. Here is the thread (see the posts by "spaaarky21" about half way down.)

http://discussions.apple.com/thread.jspa?messageID=12312095

I think this is relevant to the problems reported here. What spaaarky did to prevent the hard disk from sleeping was write a java script that wrote something to a file once per second. He claims to not have had a freeze since then. Others are reporting this technique fixes the problem.

Steve

OK...question for iMac 7,1 users. When your freezes occur, do you have external hard drives, possibly asleep, connected to your computer?

I back up once a week or so. Most of the time external is unplugged

RM

Anyone test with and without a external monitor connected ?

Okay, last week my screen freezes have become literally unbearable (that is as in about six times per day). I then happened to activate the guest account in order to get at least some urgent things done uninterruptedly. Well, and guess what, no crash while working as a "guest".

That made me wonder whether there could maybe be a single setting within my default user account that is causing the crashes. So in the end, I decided to bite the bullet, backed up my personal data to an external HDD and completely erased my user account.

I then created a blank one - making certain NOT to copy over any of the old preference files (I had to be pretty careful with that as I am syncing via MobileMe) - and in the end putting my data back in all the right places.

Anyway, to cut a long story short, I have been working with this new old user account of mine for about a week now and did not experience a single crash ... and that's without making any changes to the system underneath.

At least in my case, the cause for the screen freezes I experienced every since 10.6.3 seems to have been some sort of corrupt file within my preferences, cache files or whatever. Looking back, it was definitely worth going through the entire process of rebuilding my user from scratch.

Maybe this is an option for some of you, too?!

Cheers,
Daniel

Another update (I have several posts earlier in this thread):

I went to the Apple store to have my NVIDIA graphics chip checked about after reports of faulty chips for sold MacBook Pro's between May 2007 and September 2008:

http://www.macrumors.com/2010/09/29/nvidia-class-action-settlement-for-macbook-p ro-owners/

As it turns out my graphic chip is faulty and the logic board will be replaced. I still had 13 days Apple care so it was easy but even if you don't Apple will do it for free.

I'm not sure if the system freezes are (partially) related to the faulty chip but general performance was poor with the old chip.

I recommend anybody that has a 2007 - 2008 MacBook pro with NVIDIA graphic chip to go to the Apple store to have it checked.

While I solved my crash back on July 28 that had the same symptoms as others reported here, I ran into another potential cause that I thought I would share in case anyone else is also impacted by the following.

If you are running Microsoft Remote Desktop Connection, even the latest release (version 2.0.1), then there is a known bug that causes the kind of lockups many are reporting in this thread. Some users switched to CoRD, while after an extensive discussion, other users have discovered that leaving the Domain field blank in the RDC connection setting dialog window works around the issue. This is an inconvenience for those who connect to Windows domains, but it does work.

When RDC is running and loses the network connection while it is checking for domain access, it will lock up the desktop server such that ssh sessions into the system would still work for awhile, and iTunes will keep playing in the background for awhile. This happens fairly regularly when powering up from sleep. If you do not have any background activities running, then it will appear as if the entire Mac freezes (mouse and keyboard are suddenly unresponsive). There is a brief (10-15 second) period right before the freeze / lockup when you can quit other applications, but I usually find that accelerates when the freeze / lockup happens.

Other fixes are discussed in the links I supplied above, but removing the Domain field seems to consistently work for most users experiencing this problem.

1. Problem started happening after 10.6.3 update? after a few weeks
2. Did you get any errors during 10.6.3 update process? not that i no of
3. Mouse cursor moves? would move then freeze then move with the spinning rainbow ball
4. Mouse clicking does nothing? Yes
5. Keyboard key presses do nothing? Yes and sometiems it would skip letters
6. Only way to re-animate system is by holding down power button? Yes and sometimes wouldnt work after that
7. Mouse/Keyboard Model? snow leopard mac osx

I bought this new iMac 27" a month ago and it freezes after long sleeps. (once happened after turning on).

1. Problem started happening after 10.6.3 update? Yes
2. Did you get any errors during 10.6.3 update process? No
3. Mouse cursor moves? Yes
4. Mouse clicking does nothing? Yes
5. Keyboard key presses do nothing? Yes
6. Only way to re-animate system is by holding down power button? Yes
7. Mouse/Keyboard Model? Wireless keyboard and Magic mouse

i have reset the SMU and PRAM a couple of times and it did not solve my problem.
no external USB device is attached to the computer.

it even froze in Windows 7 x64 (bootcamp) after sleep.

i removed the bootcamp partition and it did not solve the problem either.

i disabled "automatically reduce brightness before display goes to sleep" as suggested by someone and it didn't help either.

1. Problem started happening after 10.6.3 update? Yes
2. Did you get any errors during 10.6.3 update process? No
3. Mouse cursor moves? Yes
4. Mouse clicking does nothing? No response
5. Keyboard key presses do nothing? No response
6. Only way to re-animate system is by holding down power button? This, or SSH to do sudo shutdown -r now
7. Mouse/Keyboard Model? Logitech K120 (don't see how this is relevant)

Have been having system lockups for quite a while now, although since 10.6.4 they seem to be getting worse. I'm a games developer and so often run heavy graphics stuff, but lockups also occur simply scrolling a page in Safari.

When the system locks up, I can usually SSH in, to find WindowServer in stuck state. Non-UI associated things still function. I can shutdown/restart the machine cleanly using the "shutdown" command. Occasionally the lockup will result in a black screen - usually while gaming. The display is still on as I can see the backlight. When this happens, a load of "GPU Debug Info" is written to /var/log/kernel.log.

My iMac is an iMac7,1 with the ATI HD2400 GPU and 128MB VRAM. The Mac does not appear to be getting excessively hot, certainly no hotter than it ever has done. I do clean out the vents regularly with a vacuum. The ROM revision is 113-B2250A-207 and EFI Driver version 01.00.207.

I am convinced this is a driver bug, and it seems to coincide with the improved graphics performance brought about for Valve's games (it improves ours considerably too!). Under 10.5 the system seems to be stable. I am going to try installing Windows XP or 7 and running some GPU stress such as 3DMark.

As an employee of a registered Apple developer I also have access to the 10.6.5 beta seeds.
As of build 10H562, the problem still occurs.

I'd love to know where to report this officially!

Hi again,
Well perhaps not surprisingly, I still have the problem and am still scratching my head and swearing at the machine.

Some common threads amongst all would seem to be: 1. 'waking' from sleep mode causes it 2. a suggestion that it might be a hardware compatibility problem 3a. 10.6.2 doesn't have the problem 3b.fault cannot always be reproduced at will in 10.6.3 and 10.6.4. and lastly 4. that recent Graphics Update didn't fix it!

I can confirm 1. and if I have to take my machine to Applecare (or whoever) then that area will be most likely to give an instant demo.

My actions so far include a) disconnect Time Machine and use Backup program instead b)disable all screen savers c)disable all auto-sleep actions d)disable auto dock hiding and other fancy effects d)frequent resort to switching off and not keeping the machine on for long periods. I'm running out of options now... but next might be e)disconnect MobileMe Sync and f)disconnect external hard drive except when needed for Backup program, both of which become very active after a period of sleep mode.

I need a prayer mat, or a good Apple expert!

This machine was brilliant under Tiger, never a blip.

Paul.