Level 1

133 points

CTO iMac, 3.6Ghz i5, 8Gb RAM random freezes

Hello to you all,

from day 1, October the 13th, my CTO iMac freezes randomly; it has frozen a total of 8 times, 3 of them during the last Apple Keynote, on October the 20th.

When it freezes and there is sound going, it continuously repeats the last sounds, very fast, and the first time this scared me a lot: the first time I thought the loudspeakers broke up (loud scratchy noises, like bangs).
In the other cases, the iMac just freezes, stays there, no heat, no fans going. So here what I've already done:

(1) Contacted Apple, they suggested to (and I did):
(2) Check disk - no problems
(3) Check permission - no problems, solved some inconsistencies
(4) Zap PRAM
(5) Run Hardware Test (I ran the full HW test, all is ok)

And I:

(6) Updated to 10.6.5 and to what System Update was telling me to. (10.6.5 was updated from Combo, as I always do with large system updates)
(7) Checked the temperature of the processor and other temperatures, are all ok
(8) Stressed the iMac with Call Of Duty 4, with the help of a gamer, he played for two hours two times, no freeze.

Until the end of october I had the iMac connected to my router with a Ethernet to power line communication adapter, so thinking that the problem could be related to noise on the power line, I stopped using them and, until today, the problem seemed solved.

Today, after 22 days after the last freeze, I've launched a check of one of my external HD with Sophos Antivirus (I have some Windows files there) and went to lunch. When back, the iMac was frozen, keyboard unresponsive, black screen (should this coming from power save mode).

Details:

(a) iMac i5@3.6 Ghz 8 Gb RAM, all of them same brand (0x80AD)
(b) Bluetooth keyboard and mouse
(c) Time Machine active, the TM HD normally is off, I decide when to make it.
(d) I have the full system.log; there are some errors that I can't explain, but they not always are followed by the freeze.

I've deleted the Chrome App, that was active in some cases; and almost always Safari was running.

I report pieces of my system.log just before the freezes:

(I)

Oct 13 15:07:01 Bugfixer PubSubAgent[298]: SQL Error: SQLITE_CANTOPEN[14.0]: Database file not found
Oct 13 15:09:53 localhost com.apple.launchd[1]: * launchd[1] has started up. *
Oct 13 15:09:57 localhost DirectoryService[15]: Improper shutdown detected

(II)

Oct 15 20:13:03 Bugfixer configd[13]: Hibernate Statistics
Oct 15 20:13:03 Bugfixer configd[13]: Kernel WDDMService com.apple.powermanagement.applicationresponse.cancelled
Oct 15 20:13:13 Bugfixer configd[13]: PMConnection mDNSResponder com.apple.powermanagement.applicationresponse.slowresponse 759 ms
Oct 15 20:13:49 localhost com.apple.launchd[1]: * launchd[1] has started up. *
Oct 15 20:13:53 localhost DirectoryService[15]: Improper shutdown detected

(III, this happened TWO times in a very similar way)

Oct 20 18:53:44 Bugfixer [0x0-0x28028].com.google.Chrome[288]: objc[302]: Class TaskOperation is implemented in both /Applications/Google Chrome.app/Contents/Versions/7.0.517.41/Google Chrome Helper.app/Contents/MacOS/../../../Google Chrome Framework.framework/Google Chrome Framework and /Applications/Google Chrome.app/Contents/Versions/7.0.517.41/Google Chrome Framework.framework/Internet Plug-Ins/PDF.plugin/Contents/MacOS/PDF. One of the two will be used. Which one is undefined.
Oct 20 18:53:44 Bugfixer [0x0-0x28028].com.google.Chrome[288]: objc[302]: Class WorkerPoolObjC is implemented in both /Applications/Google Chrome.app/Contents/Versions/7.0.517.41/Google Chrome Helper.app/Contents/MacOS/../../../Google Chrome Framework.framework/Google Chrome Framework and /Applications/Google Chrome.app/Contents/Versions/7.0.517.41/Google Chrome Framework.framework/Internet Plug-Ins/PDF.plugin/Contents/MacOS/PDF. One of the two will be used. Which one is undefined.
Oct 20 18:54:49 Bugfixer [0x0-0x28028].com.google.Chrome[288]: 2010-10-20 18:54:49.788 Google Chrome Helper[302:207] __CFServiceControllerBeginPBSLoadForLocalizations received error 1100 from bootstrap lookup2
Oct 20 18:58:50 Bugfixer fontd[171]: query/build result time = 0.216912 sec
Oct 20 19:42:14 Bugfixer com.apple.backupd-auto[362]: Not starting scheduled Time Machine backup - time machine destination not resolvable.
Oct 20 19:51:37 localhost com.apple.launchd[1]: * launchd[1] has started up. *
Oct 20 19:51:42 localhost DirectoryService[15]: Improper shutdown detected

(IV)

Oct 20 20:19:47 Bugfixer Nikon Message Center 2[198]: terminate
Oct 20 20:19:47 Bugfixer com.apple.launchd.peruser.501[163] (com.apple.CSConfigDotMacCert-bugfixer@me.com-SharedServices[189]): Exited with exit code: 1
Oct 20 20:20:40 Bugfixer login[217]: USER_PROCESS: 217 ttys000
Oct 20 20:22:30 Bugfixer [0x0-0x17017].com.apple.Safari[223]: FlateDecode: decoding error: incorrect data check.
Oct 20 21:27:18 localhost com.apple.launchd[1]: * launchd[1] has started up. *
Oct 20 21:27:21 localhost DirectoryService[15]: Improper shutdown detected
(V)
Oct 27 19:31:48 Bugfixer apsd-ft[204]: <APSCourier: 0x1022076f0>: Stream error occurred for <APSTCPStream: 0x102103e00>: Error Domain=kCFErrorDomainCFNetwork Code=2 UserInfo=0x10223f400 "The operation couldn’t be completed. (kCFErrorDomainCFNetwork error 2.)"
Oct 27 19:31:49 Bugfixer ntpd[25]: bind() fd 25, family 30, port 123, scope 4, addr fe80::cabc:c8ff:fe89:f4b8, in6is_addrmulticast=0 flags=0x11 fails: Can't assign requested address
Oct 27 19:31:49 Bugfixer ntpd[25]: unable to create socket on en0 (7) for fe80::cabc:c8ff:fe89:f4b8#123
Oct 27 19:31:52 Bugfixer configd[13]: network configuration changed.
Oct 27 19:31:52 Bugfixer configd[13]: Sleep: Success - AC - Software Sleep
Oct 27 19:31:52 Bugfixer configd[13]: Wake: Success - AC - EHC2
Oct 27 19:31:52 Bugfixer configd[13]: Hibernate Statistics
Oct 27 19:32:02 Bugfixer SoftwareUpdateCheck[351]: Checking for updates
Oct 27 19:32:05 Bugfixer apsd-ft[204]: <APSCourier: 0x1022076f0>: Received connected response OK
Oct 27 19:32:08 Bugfixer ntpd[25]: time reset -0.514471 s
Oct 27 19:32:22 Bugfixer loginwindow[35]: no spins reported for this wake
Oct 27 19:32:22 Bugfixer [0x0-0x31031].backupd-helper[343]: Not starting Time Machine backup after wake - failed to resolve alias to backup volume
Oct 27 19:33:59 Bugfixer SoftwareUpdateCheck[351]: SWU: scan found 0 products:
Oct 27 19:33:59 Bugfixer com.apple.launchd[1] (com.apple.suhelperd[352]): Exited with exit code: 2
Oct 27 19:33:59 Bugfixer com.apple.launchd.peruser.501[164] ([0x0-0x33033].SoftwareUpdateCheck[351]): Exited with exit code: 102
Oct 27 19:48:58 Bugfixer com.apple.backupd-auto[369]: Not starting scheduled Time Machine backup - time machine destination not resolvable.
Oct 27 19:52:50 localhost com.apple.launchd[1]: * launchd[1] has started up. *
Oct 27 19:52:56 localhost blued[17]: Apple Bluetooth daemon started
Oct 27 19:52:56 localhost DirectoryService[15]: Improper shutdown detected
(VI)
Oct 29 20:35:23 Bugfixer [0x0-0x6c06c].com.google.Chrome[650]: objc[704]: Class TaskOperation is implemented in both /Applications/Google Chrome.app/Contents/Versions/7.0.517.41/Google Chrome Helper.app/Contents/MacOS/../../../Google Chrome Framework.framework/Google Chrome Framework and /Applications/Google Chrome.app/Contents/Versions/7.0.517.41/Google Chrome Framework.framework/Internet Plug-Ins/PDF.plugin/Contents/MacOS/PDF. One of the two will be used. Which one is undefined.
Oct 29 20:35:23 Bugfixer [0x0-0x6c06c].com.google.Chrome[650]: objc[704]: Class WorkerPoolObjC is implemented in both /Applications/Google Chrome.app/Contents/Versions/7.0.517.41/Google Chrome Helper.app/Contents/MacOS/../../../Google Chrome Framework.framework/Google Chrome Framework and /Applications/Google Chrome.app/Contents/Versions/7.0.517.41/Google Chrome Framework.framework/Internet Plug-Ins/PDF.plugin/Contents/MacOS/PDF. One of the two will be used. Which one is undefined.
Oct 29 20:35:23 Bugfixer [0x0-0x6c06c].com.google.Chrome[650]: [650:24579:7185168778315:ERROR:/b/slave/chrome-official-mac/build/src/net/socke t/clientsocket_poolbase.cc(935)] No pending request for backup job.
Oct 29 20:37:14 localhost com.apple.launchd[1]: * launchd[1] has started up. *
Oct 29 20:37:18 localhost DirectoryService[15]: Improper shutdown detected
(VII)
Nov 21 13:01:27 Bugfixer Safari[523]: Error: Embedded profile header length is greater than data length.
Nov 21 13:01:27 Bugfixer [0x0-0x43043].com.apple.Safari[523]: Sun Nov 21 13:01:27 Bugfixer.local Safari[523] <Error>: Error: Embedded profile header length is greater than data length.
Nov 21 13:01:27 Bugfixer Safari[523]: Error: Embedded profile header length is greater than data length.
Nov 21 13:01:27 Bugfixer [0x0-0x43043].com.apple.Safari[523]: Sun Nov 21 13:01:27 Bugfixer.local Safari[523] <Error>: Error: Embedded profile header length is greater than data length.
Nov 21 13:03:17 Bugfixer SafariSyncClient[535]: LightweightMallornLoginSession is registered.
Nov 21 13:03:17 Bugfixer [0x0-0x46046].com.apple.Safari[532]: 2010-11-21 13:03:17.506 SafariSyncClient[535:903] LightweightMallornLoginSession is registered.
Nov 21 13:06:43 Bugfixer mDNSResponder[26]: Double NAT (external NAT gateway address 10.35.235.89 is also a private RFC 1918 address)
Nov 21 13:37:19 localhost bootlog[39]: BOOT_TIME: 1290343027 0
Nov 21 13:37:08 localhost com.apple.launchd[1]: * launchd[1] has started up. *
Nov 21 13:37:21 localhost fseventsd[31]: event logs in /.fseventsd out of sync with volume. destroying old logs. (9521 14 10864)
Nov 21 13:37:21 localhost fseventsd[31]: log dir: /.fseventsd getting new uuid: ACDF7605-4E75-445B-8081-3DBAA31EE377
Nov 21 13:37:22 localhost DirectoryService[36]: Improper shutdown detected
Thanks for your attention.

iMac 3.6Ghz i5,8Gb - iPhone 3G, iPad, Mac OS X (10.6.5)

Posted on Nov 21, 2010 12:30 PM

135 replies

babowa

Level 9

78,562 points

Dec 11, 2010 9:16 AM in response to Motion_FX

+but in my case I really know what I´m doing and I know that it´s not dangerours at all.+

Best of luck; since you know what you're doing and choosing to dismiss any cautions and the fact that you will be voiding your warranty, why are you posting questions here?

Bugfixer Author

Level 1

133 points

Dec 11, 2010 9:25 AM in response to babowa

I have to agree with Barbara.

Dec 11, 2010 9:43 AM in response to babowa

I´m posting here because at the moment I have 4 memory modules running at 1333 mhz, all these memorys are officially supported (and the four come from Apple, as the two extra modules where bought to a friend who sold them after removing them from an iMac Core i5 2010) and my Mac is not stable. I think this is a good reason to post here. And as I said, I "plan to" try the two 1066 mhz ram if nothing else works before that. And I don´t think that trying an unofficial memory speed (but fully supported by the processor) would be enough reason to stop posting here as I´m not recommending to anyone to act in the same way. But as I said, this is what I plan to do if nothing else works, until now the two memory modules running at 1066 mhz are still installed in my MacBook Pro.

Bugfixer Author

Level 1

133 points

Dec 11, 2010 1:41 PM in response to Motion_FX

Motion_FX wrote:
I´m posting here because at the moment I have 4 memory modules running at 1333 mhz, all these memorys are officially supported (and the four come from Apple, as the two extra modules where bought to a friend who sold them after removing them from an iMac Core i5 2010) and my Mac is not stable. I think this is a good reason to post here. And as I said, I "plan to" try the two 1066 mhz ram if nothing else works before that. And I don´t think that trying an unofficial memory speed (but fully supported by the processor) would be enough reason to stop posting here as I´m not recommending to anyone to act in the same way. But as I said, this is what I plan to do if nothing else works, until now the two memory modules running at 1066 mhz are still installed in my MacBook Pro.

My suggestion is to open a new thread describing your problem, so maybe more people can give you the attention you deserve; the title of this thread, in fact, is related to a particular model of iMac.

Message was edited by: Bugfixer

Dec 11, 2010 4:05 PM in response to Bugfixer

I can watch the entire keynote, play dvd's etc with no issue, It is most odd that some but not all have this issue. I hope you find the cause.

saturne

Level 1

0 points

Dec 12, 2010 4:17 AM in response to killhippie

Hello,

I have the exact same issue with an imac core 2 duo 2010, 8gb (origin apple, came with the computer), 10.6.5.
I tried to remove 4 gb : no crashes!
What do you people think i should do? Reinstall the system (it really seems to be the ram, so i don't think it will fix the problem)? I'd like to call apple, but right now i can't afford to be without computer since i'm working with it.

Thanks.

Bugfixer Author

Level 1

133 points

Dec 12, 2010 4:36 AM in response to saturne

saturne,

If I were you, I would reinstall the os first; in my case made no difference and, if you've read my last messages, at the lab they decided to change the logic board; the symptoms at last pointed to the RAM, but the RAM chips were all ok.

And if this doesn't work you have to call Apple, in my opinion.

Bugfixer Author

Level 1

133 points

Dec 12, 2010 4:40 AM in response to killhippie

killhippie wrote:
I can watch the entire keynote, play dvd's etc with no issue, It is most odd that some but not all have this issue. I hope you find the cause.

As I wrote, it seems the prolem was the motherboard, the repair lab will install a new one.

Bugfixer Author

Level 1

133 points

Dec 15, 2010 10:40 AM in response to Bugfixer

My iMac is back. I'm currently restoring by a Time Machine backup.

So the problem was the mother board (or logic board, if you prefer). The problem was related to a faulty slot or a component related to the memory slot management, that's the reason why with 4 Gb of RAM everything worked properly.

The first thing that I made once at home was to test with the Apple keynote, and it worked fine.

So I'm marking this thread as SOLVED (answered).

My suggestion to all the people following this thread with similar problems is to contact Apple service and explain in detail the problem; I've noticed that if the problem is reproducible is much better, obviously.

Feb 14, 2011 6:45 PM in response to Bugfixer

iMac i5 3.6 Ghz 8GB 2TB
My iMac randomly freezes.
When I'm using FCP or surfing with Safari.
I'm at my wits end. Tried everything that I know.
I've had the mac for a month.
How many times must I bring it to Apple before they change the motherboard?
Will they tell me there is no problem... the first time I bring it?
Does Apple need to see a freeze before they do anything?
Any suggestions on how best to pursue this, I really don't have time for the run around.

Feb 15, 2011 1:52 PM in response to EmpireApple

Reduce your RAM to 6Gb and test. It should be fine. There's a problem with having 8Gb of Apple RAM.

Mar 26, 2011 7:03 PM in response to Bugfixer

Update
Just got my iMac back for the second time.
Again Apple has said there's nothing wrong with the computer.
Apple erased the hard drive.
I just tried to upload Time Machine... it froze.
Tried it again, it worked, got everything back.
Then wanted to update software.
Downloaded updated software, then when it rebooted and started to install, it froze.
Did it again.. it froze.
Now just bringing in the updated OS, it worked, rebooted.
Went to Safari... it froze.
Why doesn't the computer freeze when Apple has it?
Is Apple lying?

BrianF

Level 1

44 points

Apr 21, 2011 5:17 PM in response to Bugfixer

Hi,

I had the exact same problem, iMac 21.5" i3, 8 gigs of RAM.

The problem started about 2 weeks ago for no known reason. No new software, no updates preceding it, just started freezing. It would freeze every time we changed users and sometimes when just trying to log into a user.

I think I fixed it. No Freezing and hard restarts since. I disabled Screen Sharing.

After going over log after log. disabling 3rd party software, DiskWarrior, cleared caches, all the multitude of maintenance steps. Nothing worked.

Then 2 nights ago, I realised I had turned on Screen Sharing about the time the freezing started. I turned it off and all seems well.

Your mileage may vary.

Brian

Jul 18, 2011 5:03 AM in response to BrianF

I have been having a similar issue. (https://discussions.apple.com/thread/3175303)

I found running the Prime95 memory stress test was able to induce a crash on a reproducible basis, within about 30min.

You can get Prime95 free from here: http://www.mersenne.org/freesoft/

This could be helpful for those sending it back to Mac, so that you can tell them how to get the system to crash.

I had similar issues, where the machine would not crash for the day that the IT department tested it, so they thought I was crazy.

Thankfully I have managed to convince them otherwise.

Bugfixer Author

Level 1

133 points

Nov 8, 2011 3:12 AM in response to Bugfixer

Update on this issue. After almost one year, the iMac was giving me the same problem again, so I went to a Genius Bar. I've opened a new thread on this issue, but the problem revealed to be the same:

https://discussions.apple.com/thread/3215984?answerId=15792600022#15792600022

Well, this time the change of the the motherboard didn't solve the problem. They changed also the video card and again the problem of the freeze happened again.

A third try went with the change ofthe 8Gigs of RAM, but with no result, the freeze and the noises happened again.

Well, Apple decided to give me a new iMac. I suspect that there are some problems with the 3.6Ghz i5 motherboard that have never been solved. (and in fact a so high frequency is not used anymore).

In a couple of weeks I'll receive the new CTO Mac.

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

CTO iMac, 3.6Ghz i5, 8Gb RAM random freezes