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Late 2007 iMac 20" Freezes completely random.

"Good news everyone!" -Professor Farnsworth.

What a great quote. While this news may not be good yet, it has the potential to be. Today Apple released 10.7.3 and one of the bug fixes it "Address a graphics performance issue after sleep on some earlier iMacs that use ATI graphics". This could be the fix for the GPU crashing that is plaguing our iMacs. Also looking at the Snow Leopard 2012-001 Security Update, it appears that Apple has changed some graphics related extensions. Hopefully this security updates provides the same GPU crashing fixes.

Edit: Spoke too soon. My 10.6.8 iMac crashed shortly after installing the update. Maybe the fix is only for 10.7.3.
 
Last edited:
Does downgrade from 10.6.8 help?

Hi,
I think I have exactly the same problem. I was running Tiger on a 2007 iMac with 2Ghz and 2GB (which was how I bought the machine). I never had problems. But various videoplayers now asked for a new version of Silverlight which couldn't be installed on Tiger. So I decided to install Snow Leopard from a retail CD. I did a clean install. Once every while the system freezes, either with the beachball running, or (often) I can still move the mouse cursor, but I cannot activate anything.

I think it is mostly when I am using Safari and e.g. youtube or a flash children's game (btw I have internet via ethernet cable).
But I think it even happens without internet.

(I just got my iMac out of sleep mode - ethernet cable has been out for an hour or so, and the whole screen is full of noise: the pixels don't seem to update correctly, half the windows are there and the background is total pixel chaos!? haven't seen that until now. Activity monitor doesn't show anything strange. I opened desktop and screen saver, clicked on 'change background', the background became clean again but the window had strange black lines behind it - and now the system hangs)

btw I installed MacOffice2004 - but the system hangs when none of that software is running. would it still matter?

I've read the following advice so far:

- vacuumclean the machine (I tried this, had no problems for a whole evening, then they returned)
- repair permissions (Did this several times, seems to help for a while, but in the end the freeze comes back again)
- upgrade RAM (haven't tried this yet, I think 2GB should work - is this really worth the try??)
- Somebody in this thread suggested to downgrade to 10.6.6. Did anyone try this and did it help? Did the OP (or anybody else) solve finally solve the problem?
- reboot in safe mode (did that multiple times)

I even consider downgrading (reinstalling) Tiger again from my original cd. ... :-((((
Thanks for any help.
 
10.6.6 is the last version of Mac OS X that doesn't exhibit this crashing.

Having Office 2004 installed isn't a factor in these crashings. The system still crashes with a clean default install of 10.6.8 with no other non-Apple software installed.
 
Intell - how's your system after the update? Any more crashes? Do you think it's software or hardware?

I have my own thread here and still having issues :( I have stacks of of crash reports but not sure if it's soft or hardware
https://forums.macrumors.com/threads/1285964/

Kernel Extensions in backtrace:
com.apple.NVDAResman(7.1.8)[94BA87BA-
 
With the Snow Leopard 2012-001 Security Update version 2, I still get freezes. After looking through your thread, I noticed that you are getting kernel panics. The problem that I'm getting, as well as many others, is the GPU basically stops working or crashes, with only the mouse still active. No crash log, not kernel panic. The only way I've been able to get any kind of log, was to SSH into my iMac from another Mac and view the syslog. It was full of debugging junk relating to the GPU. After more searching I discovered that it's happened before with other Macs with ATI 2400/2600 video cards.

I am 99% sure this is not a hardware problem, but a software problem that exists in 10.6.7-10.7.2/3. Reasons being, it doesn't crash in Boot Camp when playing games or general usage, it runs fine in 10.6.6 with no crashing, I've decoded about 20 dvd's on it with the fans at stock in Leopard as a test, no crashing even though the GPU got very warm.

Your issue could be related to Lion. If it does indeed work fine in Snow Leopard, then Lion's Nvidia drivers are the cause.
 
Thanks for the update, and advice! :)

Similar situation in that I can play games for hours and not crash like yourself in boot camp. I've subscribed to this thread to keep on top of updates. Keep us informed how it goes and what you find!
 
Thanks

Thank you very much Intell for all the research. You've really analysed this very thoroughly IMO. I suppose the best way to downgrade is to re-do my clean-install (and then not update beyond version .6)?
 
Just curious, do you use Chrome or Rockmelt? If so, when it freezes, let it sit for a minute and try to click the Apple logo at the top left corner. If it lets you, force quit Chrome and see if things go back to normal. My Chrome randomly does this from time to time. Took me months to figure out the cause. It started right after i updated to Lion.
 
jelle1975 said:
Thank you very much Intell for all the research. You've really analysed this very thoroughly IMO. I suppose the best way to downgrade is to re-do my clean-install (and then not update beyond version .6)?
Click to expand...

You're welcome. I've simply reinstalled Snow Leopard Retail right over my 10.6.8 installation before. I didn't wipe it and I don't think it was an archive and install. But when I did do this and didn't go past 10.6.6, all was well.

cocky jeremy said:
Just curious, do you use Chrome or Rockmelt? If so, when it freezes, let it sit for a minute and try to click the Apple logo at the top left corner. If it lets you, force quit Chrome and see if things go back to normal. My Chrome randomly does this from time to time. Took me months to figure out the cause. It started right after i updated to Lion.
Click to expand...

I don't use Chrome. I've left my iMac sit all night in its frozen state. The computer I used to keep track of my iMac's syslog was still showing scrolling crash/debug info. I'm not sure, but I think the only way to recover from these GPU crashes is by powering off the iMac. I'll do some more tests today to see if I can catch exactly what the kill line is.

Who wants a crash log? See attachment. I've further discovered that this is sometimes logged to the kernel log and sometimes it isn't logged at all. Maybe if enough people extracted this crash from their kernel log after a crash and submitted it to Apple's Feedback section or at least complained to Apple about it, they'll fix it.
 

Attachments

  • GPU Crash Log.txt
    63.9 KB · Views: 453
Last edited:
Black screen

Ok new puzzle.
I did a clean install of 10.6 from the retail disk.
Then I installed the 10.6.6. combo update.
Then I opened safari.
I went to this website where I knew I had problems before, it is a website with flash-games for children (www.spele.nl)
I clicked on some game. Briefly the game started to load.
Then: black screen (not sleep-mode black but 'no content' black).
I restarted with the power button (don't know if there would have been other options, I think not).

Any ideas?

Should I first install some update of flash (or should I instead NOT install a certain version of flash?)
Just now I did 'repair permissions', but don;t know if that will help...
 
jelle1975 said:
Ok new puzzle.
I did a clean install of 10.6 from the retail disk.
Then I installed the 10.6.6. combo update.
Then I opened safari.
I went to this website where I knew I had problems before, it is a website with flash-games for children (www.spele.nl)
I clicked on some game. Briefly the game started to load.
Then: black screen (not sleep-mode black but 'no content' black).
I restarted with the power button (don't know if there would have been other options, I think not).

Any ideas?

Should I first install some update of flash (or should I instead NOT install a certain version of flash?)
Just now I did 'repair permissions', but don;t know if that will help...
Click to expand...


I got that sudden black screen once about a week ago on 10.6.8 on my iMac. I was reading Wikipedia at the time and it just went black. No idea what caused it.

Pending the Flash update, you should always update Flash. It is one of the buggiest and security holed pieces of software ever made.

Don't forget to complain to Apple about this. See my previous post.
 
My best guess is in updating somewhere, your firmware for your mac/gpu/logic board went wrong and is causing software incompatibilities.

A new logic board might be the answer?
 
My iMac's firmware was last updated in late 2007. Never had a problem. My iMac is not eligible for the video update, just the firmware one.
 
I've had the same problem, with the same model. The problem started when I upgraded to 10.6.8, disappeared for a while after switching to Lion, and then suddenly came back.

In the end, resetting the PRAM turned out to solve it for me.

How to do a PRAM reset:

1. Shut down the computer.

2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.

3. Turn on the computer.

4. Immediately press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.

5. Continue holding the keys down until the computer restarts, and you hear the startup sound for the second time.

6. Release the keys.

Apple Support page on resetting PRAM

Note that the restart might take quite a while, so don't worry if it seems to take longer than it should.

I'm guessing that it isn't a permanent fix, since I highly suspect that the issue results from a bug in some system processes resulting in corrupted values in the PRAM under a specific set of circumstances. So if the same set of circumstances occurs again, the problem will probably come back and another PRAM reset will be necessary.
 
problems not gone.... :-(

Just to follow up on what happened: it really seems to be playing video in a web-browser that is causing the problems. What I see just before it crashes is white pixels tracing over the video screen or just above or below it in the web-browser window. Sometimes pixelblocks left behind/not updating. I also have a feeling that the quality of the video is actually worse then it was with the old flash player and the old OSX (tiger)?

I upgraded flash player and also installed flip4mac (because all tv show reruns use the newest Silverlight and my download of Silverlight was causing problems too). Also in Flash I desabled 'enable hardware accelleration', that really seemed to help straight away.

After that it, it actually seemed to be ok for a while, we watched a whole show in full-screen over the evening, everything fine (did some testing: full screen and back, back in timeline and forward, etc).

But today twice I had again a dark-blue screen (like the screen is off but not totally). Once, when I hit the power button only lightly (as if taking it out of sleep) the screen actually came back and everything continued as normal.

And once I even had everything turning reddish (all green out of my colour palette), and......this caused the 'mouse still moves but nothing clickable' crash again.

The only difference since yesterday is that I again installed my old version of Office 2004 - but I wasn't running any of its applications, it's always video in the webbrowser (e.g. youtube and so on).
 
We should start compiling a list of common things. I suggest we start with the Graphics/Display part of System Profiler. If you are having this issue, please post it in an attempt to isolate the cause. Copy and paste it into your post like I did:

Code: 
ATI Radeon HD 2400 XT:

  Chipset Model:	ATI,RadeonHD2400
  Type:	GPU
  Bus:	PCIe
  PCIe Lane Width:	x16
  VRAM (Total):	128 MB
  Vendor:	ATI (0x1002)
  Device ID:	0x94c8
  Revision ID:	0x0000
  ROM Revision:	113-B2250A-207
  EFI Driver Version:	01.00.207
  Displays:
iMac:
  Resolution:	1680 x 1050
  Pixel Depth:	32-Bit Color (ARGB8888)
  Main Display:	Yes
  Mirror:	Off
  Online:	Yes
  Built-In:	Yes
Display Connector:
  Status:	No Display Connected
 
The dutch version..

Hardwareoverzicht:

Modelnaam: iMac
Modelaanduiding: iMac7,1
Processornaam: Intel Core 2 Duo
Processorsnelheid: 2 GHz
Aantal processors: 1
Totaal aantal cores: 2
L2-cache: 4 MB
Geheugen: 2 GB
Bussnelheid: 800 MHz
Opstart-ROM-versie: IM71.007A.B03
SMC-versie (systeem): 1.20f4
Serienummer (systeem): W8743B5VX85
Hardware-UUID: 00000000-0000-1000-8000-001B63ABFC90

----------

ATI Radeon HD 2400 XT:

Chipsetmodel: ATI,RadeonHD2400
Type: GPU
Bus: PCIe
Breedte PCIe-baan: x16
VRAM (totaal): 128 MB
Fabrikant: ATI (0x1002)
Apparaatcode: 0x94c8
Revisiecode: 0x0000
ROM-revisie: 113-B2250A-207
Versie EFI-besturingsbestand: 01.00.207
Beeldschermen:
iMac:
Resolutie: 1680 x 1050
Pixeldiepte: 32-bits kleur (ARGB8888)
Hoofdbeeldscherm: Ja
Synchrone weergave: Uit
Online: Ja
Ingebouwd: Ja
Beeldschermconnector:
Status: Geen beeldscherm aangesloten

----------

we have exactly the same system so far
 
Can't copy my specs but from memory;

iMac early 2009
2.93ghz core 2 duo
Nvidia GT 120

Daily lookups galore on clean 10.7.3 installs
 
musio your issue is different. Your issue is caused by general instability with Lion. The issue others in this thread are having is caused by a faulty ATI kext in 10.6.7 and newer.
 
Code: 
NVIDIA GeForce GT 120:

  Chipset Model:	NVIDIA GeForce GT 120
  Type:	GPU
  Bus:	PCIe
  PCIe Lane Width:	x16
  VRAM (Total):	256 MB
  Vendor:	NVIDIA (0x10de)
  Device ID:	0x0655
  Revision ID:	0x00a1
  ROM Revision:	3370
  Displays:
iMac:
  Resolution:	1920 x 1200
  Pixel Depth:	32-Bit Color (ARGB8888)
  Main Display:	Yes
  Mirror:	Off
  Online:	Yes
  Built-In:	Yes

musio said:
Intell - how's your system after the update? Any more crashes? Do you think it's software or hardware?

I have my own thread here and still having issues :( I have stacks of of crash reports but not sure if it's soft or hardware
https://forums.macrumors.com/threads/1285964/

Kernel Extensions in backtrace:
com.apple.NVDAResman(7.1.8)[94BA87BA-
Click to expand...

I get the com.apple.NVDAResman part in almost all of my crash report/kernel panic reports, too.
 
Other same card owners are having issues like me. Not only here but on the Apple forums. I've tried a clean install with 10.7.3. In fact not only my card but of other gpu issues are reported from lots of different cards. Maybe lion is frying the hardware with their driver updates in lion? Apple are taking my mac back for a new logic board
 
The problems associated with non-ATI 2400/2600 cards is not the same as those with ATI 2400/2600 cards. One is a kernel panic and the other is a GPU crash.
 
Intell said:
The problems associated with non-ATI 2400/2600 cards is not the same as those with ATI 2400/2600 cards. One is a kernel panic and the other is a GPU crash.
Click to expand...

i got the same problems with a 20inch 2007 2.4 4gb ram and ati 2600pro. It freezes sometimes complete and crawls when it isn't freezing. Ram is fine as far as i can see (tested it with different machine). idk what the problem may be :/ i am on lion 10.7.2
 
maril1111 said:
i got the same problems with a 20inch 2007 2.4 4gb ram and ati 2600pro. It freezes sometimes complete and crawls when it isn't freezing. Ram is fine as far as i can see (tested it with different machine). idk what the problem may be :/ i am on lion 10.7.2
Click to expand...

By freezing, do you mean that only the mouse works but nothing else moves on the screen? Could you post the Graphics/Displays section of your System Profiler output?
 
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