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

Dec 9, 2010 9:45 AM in response to grueda

Hi Guys. How are you? Anything new in our battle?

I keep with my freezes... I called Apple and were doing tests (HW test, reset SMC, PRAM, etc) but that didn't solve the problem, then I've been told to take the computer back for technican service and that they say that all those tests are made by connecting to the wifi, since it seems that only freezes when it is using wifi.
On Monday I will take. I will tell you the results.

Bye

Bugfixer Author

Level 1

133 points

Dec 9, 2010 10:13 AM in response to navginrau

navginrau wrote:
Hi Guys. How are you? Anything new in our battle?

I keep with my freezes... I called Apple and were doing tests (HW test, reset SMC, PRAM, etc) but that didn't solve the problem, then I've been told to take the computer back for technican service and that they say that all those tests are made by connecting to the wifi, since it seems that only freezes when it is using wifi.
On Monday I will take. I will tell you the results.

Bye

Navginrau,

I've got news. Today I called to know how the tests were proceeding, and they told me that the iMac froze a couple of times, even installing the operating system; they recognize there is a problem with 8Gb of Ram, but they have not seen it before. The ram passes all tests, but with 8Gb of ram installed it freezes. If they install 4Gb only, it works well with no freeze.

They will test again. I asked them to change brand of ram, but they just can't. Apple's diktat.
they will call me the following days to have a final response; I hope they will replace the iMac, I don't see any other possibility at the moment.

Dec 9, 2010 10:38 AM in response to Bugfixer

I hope that if they can't find a definitive solution to your Imac exchange it for a new one in perfect conditions.
Should give you a new one, you change the hard disk? Or you leave the same hard disk? I say you abaut your personal data, how are you sure you have deleted all data from your old Imac?

grueda

Level 1

0 points

Dec 9, 2010 10:49 AM in response to navginrau

after a clean install, my mac seems to be really stable, no problems at all. The only one exception was powerpoint 11, but after a reinstall seems to be ok (msft is always a surprise); so I can tell my mac is working as expected; fantastic. Hope it will stay that way!

Bugfixer Author

Level 1

133 points

Dec 9, 2010 10:51 AM in response to navginrau

navginrau wrote:
I hope that if they can't find a definitive solution to your Imac exchange it for a new one in perfect conditions.
Should give you a new one, you change the hard disk? Or you leave the same hard disk? I say you abaut your personal data, how are you sure you have deleted all data from your old Imac?

They have already formatted the drive, so I have to trust them... I don't know the procedure in this case, but if they replace the iMac, it makes sense you've got a new one.

Bugfixer Author

Level 1

133 points

Dec 9, 2010 10:52 AM in response to grueda

grueda wrote:
after a clean install, my mac seems to be really stable, no problems at all. The only one exception was powerpoint 11, but after a reinstall seems to be ok (msft is always a surprise); so I can tell my mac is working as expected; fantastic. Hope it will stay that way!

Happy for you, powerpoint seems to be the problem. So you fixed it!

Dec 9, 2010 12:09 PM in response to Bugfixer

I also had a freeze today. It was just after unplugging a USB hard drive. But I still think that the problem comes from the 8 gb.
I also called Apple and they told me to delete all the caches. I don´t think that this is going to solve anything.
But I´m going to test something that I think should interest you all. If I have more freezes I´m going to test the iMac with 8 gb but only in two memory modules, as I have two memory modules of 4 gb in my MacBook Pro. They are 1066 mhz modules, but I tested them before buying the two extra modules (my Mac was not BTO, I upgraded it myself with the same Hynix memory modules that came with the iMac) and they worked fine, even if the memory speed was set to 1066 mhz. If this works I think that the next step will be testing the Mac with only 6 gb (3x2 gb modules) and if it works again on thing would be clear: the problem will be in populating the four slots. At that time I will decide what to do. Maybe the easiest solution will be to buy two 4 gb modules and sell the 4 modules of 2 gb that I have.

I will keep you informed.

babowa

Level 9

78,562 points

Dec 9, 2010 5:37 PM in response to Motion_FX

Please read this article:

http://support.apple.com/kb/HT3918

especially this:

Notes:

+i5 and i7 Quad Core iMac computers come with both top memory slots populated. These computers will not start up if only a single DIMM is installed in any bottom slot; these computers should operate normally with a single DIMM installed in any top slot. Core Duo iMac computers should operate normally with a single DIMM installed in any slot, top or bottom. ("Top" and "bottom" slots refer to the orientation of the slots in the pictures below. "Top" refers to the slots closest to the display; "bottom" refers to the slots closest to the stand).+

Also, you should NOT install modules which do not meet the specs of the Mac. Of course, it is your machine to do with as you wish, but you may be gambling with the validity of your warranty by not adhering to the published specs.

Bugfixer Author

Level 1

133 points

Dec 10, 2010 12:57 PM in response to Bugfixer

Update: this afternoon I've received an email from the lab: they have ordered a new logic board. So the response is a defective logic board, guys. At least in my case.

I will mark this thread as "Solved" if and only if I could have my iMac back and I could verify it's proper behavior for at least 3 weeks.

Dec 10, 2010 2:31 PM in response to babowa

Thanks for the advise, but let me show you one different link: http://ark.intel.com/Product.aspx?id=46473

These are the official specifications of the processor that my iMac has. As you can see, 1066 mhz memory is supported. So Apple can say what they want, but, as the memory controller is inside the processor 1066 mhz is fully supported by this computer, even if Apple doesn´t recognize it. There´s nothing that Apple could do in hardware to make those computers not being compatible with the official specs of the main processor. And believe me: I´ve seen tons of Macs working with memorys not being supported by Apple but being in an official way by the chipset or the processor of that Mac running rock stable and with no problems during years with heavy workload....

babowa

Level 9

78,562 points

Dec 10, 2010 3:37 PM in response to Motion_FX

Well, as I said, it's your machine.... I've read that Apple uses hardware (such as processors) especially created and manufactured for them, so what you linked to may be the PC equivalent with the specs for the especially created Mac processors not available because that is how Apple operates; I would not add anything that does not meet the exact specs Apple publishes.

So, good luck; and I hope that you will not need Apple's warranty service if you decide to add something that does not meet their specs. Chances are that they will not honor their warranty. You might want to read through the terms (note the second page with all the exclusions):

http://www.apple.com/legal/warranty/

Dec 11, 2010 1:24 AM in response to babowa

Apple does have some "special" processors like those used in the MacBook Air. The iMac processors are absolutely normal processors. If you go to hardmac.com you´ll see that it´s possible to change the processor that come with a lot of Apple computers. There is no sense to ask Intel to make a special i3 processor that only supports 1333 mhz memory. It would cost them a lot of money with no benefits of any kind. I know what I´m talking about: I´m a hardware technician since a while. And if it was the case then the iMac should not have booted, what the computer did when I tested the memory from my MacBook Pro. If you feel that you have to do everything that Apple says because you know nothing about hardware I think it´s ok, it´s the best way to not having problems. But this is not my case, I know what kind of things are true and what are not true. And if the processor supports 1066 mhz memory, it will be no problem.
And in the worst case, if my iMac didn´t support 1066 mhz they´ll never know that I used this memory. There is no chip inside a Mac who registers all the memory you put inside...

Dec 11, 2010 4:43 AM in response to Motion_FX

As i thought none of the things that Apple technicians told me to do worked: one more freeze.

I´m going to test the iMac with only 6 gb...

Bugfixer Author

Level 1

133 points

Dec 11, 2010 5:42 AM in response to Motion_FX

My advice is to contact Apple if AppleCare or warranty is active. I did it late (more than a month and a half after the first symptom) thinking I could solve it on myself or just understand what was going on. I was just wrong; they told me they will replace the logic board because defective.

Regarding the speed of the memory, you are free to whatever you want with your Mac, but it's not only the single chip specs that count here, but what Apple has tested and what speed they have chosen for your Mac. A macintosh motherboard is a complex object that was designed with accuracy. I have a job similar to what you say, and after 20 years of experience in firmware programming I have learned much on hardware design; if Apple says that must be the speed, that's the speed. Yes, it's intuitive that a lower speed should work (especially if compatible), but don't forget that you can have much more on the board over the microprocessor and memory.

Dec 11, 2010 6:20 AM in response to Bugfixer

I´ve already contacted Apple. The problem in my case is that the freeze occurs every 2 o 3 days after intensive use of the computer. There is nothing that makes it freeze as often as yours. So I want to be really sure what makes the computer freeze. For example: the video of the keynote didn´t cause any problem in my computer.

Regarding the speed of the memory believe me, I have enough knowledge in hardware and computers. If the firmware was programmed to make the memory below 1333 mhz to work two things can happen: the computer does not boot or the memory is overclocked to 1333 mhz which would have very low risk for the hardware, as normally this makes the computer freeze, but it does not damage permanently the hardware. I´ve been an overlocker during years and I´ve forced tons of hardware. I understand that a lot of people don´t want to make those "experiments", but in my case I really know what I´m doing and I know that it´s not dangerours at all.

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