imac shutting down unexpectedly

Question

Level 1

0 points

imac shutting down unexpectedly

iMac shuts down at random and seems to be attributed to invalid volume file count. I managed to successfully repair the disk and permissions through 'Utilities' on the Installation CD but problem reoccurs - after each unexpected shutdown Disk Utility reports another invalid volume file count.

Typing 'shutdown cause' in the all messages filter of Console reports no result - its like it never happened!

So far it has shutdown 10/12 times today, although the last shutdown was the longest interval yet: an hour or so.

iStats show CPU temperatures as fairly normal:

CPU 52
CPU Heatsink 46
Ambient 26
Mem 49
CPU Diode 60

any thoughts?

iMac, Mac OS X (10.5.8)

Posted on Oct 13, 2010 7:18 AM

Reply

Answer 1

rubmir

Level 1

4 points

Jun 14, 2017 5:36 PM in response to 23degreesN

Hola Amigos.

SPOILER: Dale un meneo!

SOLUTION: Shake it a little bit, fan speed to max, and dust will take off..

Solamente quería compartir mi experiencia, con final feliz.

Mi iMac del año 2013 se me apagaba repentinamente, seguidamente no arrancaba, pues tenia q desenchufarlo de la corriente por unos 15minutos, y entonces volvía a funcionar.. hasta que a las horas.. volvía a pasar. Desesperante! ya que mi el servicio de apple care solamente me propone resetear la PRAM, etc.. Por supuesto 0 garantía. Me afectaba al trabajo diario, ya que un render de 3 horas se volvía un suplicio: ¿Se apagará? El cliente está esperando por favor.... O; ostras! hacia 1 hora que no había guardado y PAM! Si estas leyendo esto ya sabes de lo que hablo...

Pero hace una semanita, pasó lo siguiente.. me fui a un apartamento en la playa con mi pareja, y tenía que trabajar. Pues cargué con mi iMac de 27" para allá, en sus cajas correspondientes, bien protegido, con mucho cuidado. Un viaje en coche de 1 horita. Lo subo al apartamento; lo instalo, y con un software gratuito que controla los ventiladores del iMac (smc Fan Control), ya que hacía calorete, los pongo al MÁXIMO, por si eso fuera a ayudar en algo para que no se volviera a apagar!

A los 2 minutos, veo que por la parte trasera se expulsan unos trozos de lo que parecía polvo a grumitos, suciedad acumulada, casi negra, pequeños trocitos por toda la base esparcidos..

A día de hoy, no se me ha vuelto a apagar mas... (y que siga así por favor)

Fuente de alimentación? El cable? O solamente obstrucción en la refrigeración? El caso es que por el momento, no hay mas apagones, y mi pelo ha dejado de caer (un poco menos, pero cae).

Mi opinión; el periplo de mover el equipo, viajar, abrir, cerrar, subir, bajar... desinstalarlo e instalarlo, movió porquería q calentaba los circuitos, interfería en la corriente, obstruía la ventilación, etc.. y como si de un trozo de comida obstruida en las vías se tratara, al expulsarlo, volvió a funcionar bien.

Espero que os haya ayudado en algo.

Salut!

Reply

Answer 2

Jul 17, 2017 7:18 PM in response to rubmir

After 18 months of shutdown agony I was very frustrated. The local Apple Shop could never replicate the problem or find anything wrong with the computer.

In the middle of autumn here in southern Australia the problem became so bad that the computer was shutting down several times a day, including when it was asleep with no programs running or connection to the internet or to the Time Machine backup. It also used to sometimes die when I was shutting the machine down.

The straw that broke the camel's back was when it did that during a restart after a system update and corrupted the operating system so badly that Apple Support suggested I wipe the hard drive and reinstall the operating system from scratch. Even getting the existing information off the computer and onto a portable hard drive became a nightmare because the computer would abruptly shut down while I was doing it.

In desperation I decided to do what others have done and get the local Apple Shop to replace the power supply unit. Before replacing the power supply the local Apple Shop tested the computer again and still couldn't find anything wrong. One month later and I haven't had a shutdown.

If you are having this shutdown problem I would highly recommend that you try replacing the power supply first before spending money on replacing video cards, screens, CPUs etc.

You will probably have to insist that they do that first because they will still argue until the cows come home that it is likely to be one of the other components and not the power supply. Given how often replacing the power supply has solved people's shutdown problems that is not always true.

Reply

Answer 3

den.thed

Level 9

76,858 points

Oct 13, 2010 9:50 AM in response to 23degreesN

Hi 23dedreesN

Welcome to Apple Support Communities

Check for loose electrical connections and reset or replace that surge protector if it's old.

Run the Apple Hardware Test > http://support.apple.com/kb/HT1509

Dennis

Reply

Answer 4

23degreesN Author

Level 1

0 points

Oct 13, 2010 10:52 AM in response to den.thed

Dennis,

Thanks I will try that. In the mean time I ran Diskwarrior which gave me the following report:

DiskWarrior scanned the disk named "iMac 596GB" checking all files and folders for damage and potential
compatibility problems.
Permissions:
Started verify/repair permissions on disk disk0s2 iMac 596GB
Permissions differ on "System/Library/CoreServices/Front Row.app/Contents/CodeResources", should be -rw-r--r-- ,
they are lrw-r--r--
Permissions differ on "System/Library/CoreServices/Front Row.app/Contents/PlugIns/DVD.frappliance/Contents/
CodeResources", should be -rw-r--r-- , they are lrw-r--r--
Permissions differ on "System/Library/CoreServices/Front Row.app/Contents/PlugIns/FRSettings.frappliance/
Contents/CodeResources", should be -rw-r--r-- , they are lrw-r--r--
Permissions differ on "System/Library/CoreServices/Front Row.app/Contents/PlugIns/FRSources.frappliance/
Contents/CodeResources", should be -rw-r--r-- , they are lrw-r--r--
Permissions differ on "System/Library/CoreServices/Front Row.app/Contents/PlugIns/Movies.frappliance/Contents/
CodeResources", should be -rw-r--r-- , they are lrw-r--r--
Permissions differ on "System/Library/CoreServices/Front Row.app/Contents/PlugIns/Music.frappliance/Contents/
CodeResources", should be -rw-r--r-- , they are lrw-r--r--
Permissions differ on "System/Library/CoreServices/Front Row.app/Contents/PlugIns/Photos.frappliance/Contents/
CodeResources", should be -rw-r--r-- , they are lrw-r--r--
Permissions differ on "System/Library/CoreServices/Front Row.app/Contents/PlugIns/Podcasts.frappliance/
Contents/CodeResources", should be -rw-r--r-- , they are lrw-r--r--
Permissions differ on "System/Library/CoreServices/Front Row.app/Contents/PlugIns/TV.frappliance/Contents/
CodeResources", should be -rw-r--r-- , they are lrw-r--r--
Permissions differ on "System/Library/PrivateFrameworks/BackRow.framework/Versions/A/CodeResources", should
be -rw-r--r-- , they are lrw-r--r--
Permissions differ on "Library/Internet Plug-Ins/JavaPluginCocoa.bundle/Contents/CodeResources", should be -rwrw-
r-- , they are lrw-rw-r--
Warning: SUID file "System/Library/PrivateFrameworks/DiskManagement.framework/Versions/A/Resources /
DiskManagementTool" has been modified and will not be repaired
Warning: SUID file "usr/sbin/pppd" has been modified and will not be repaired
Warning: SUID file "usr/sbin/vpnd" has been modified and will not be repaired
ACL found but not expected on "Applications/Utilities"
Finished verify/repair permissions on disk disk0s2 iMac 596GB

Disk: "iMac 596GB"
The Property List data was checked in 7,988 files.
The Resource Data was checked in 6,689 files.
The maximum Folder Depth on this disk is 21. This does not exceed the maximum recommended depth.
The System Symbolic Link Files were checked and no problems were found.
Location: "Desktop"

File: "._Info.plist"
Detected that Property List data is damaged and cannot be repaired.
XML parser error:
Unexpected character
at line 1
Old-style plist parser error:
Unexpected character '0x5' at line 1
Location: "iMac 596GB/System/Library/Modem Scripts/HUAWEI Mobile.ccl/Contents/"

File: "._version.plist"
Detected that Property List data is damaged and cannot be repaired.
XML parser error:
Unexpected character
at line 1
Old-style plist parser error:
Unexpected character '0x5' at line 1
Location: "iMac 596GB/System/Library/Modem Scripts/HUAWEI Mobile.ccl/Contents/"

File: "com.apple.iphotomosaic.plist"
Detected that Property List data is damaged and cannot be repaired.
Conversion of data failed. The file is not UTF-8, or in the encoding specified in XML header if XML.
Location: "iMac 596GB/Users/imac24/Library/Preferences/"

Reply

Answer 5

23degreesN Author

Level 1

0 points

Oct 13, 2010 11:21 AM in response to den.thed

Connections all seem good.

I ran the AHT - no problems found.

Reply

Answer 6

den.thed

Level 9

76,858 points

Oct 13, 2010 11:54 AM in response to 23degreesN

When you say "shutting down unexpectedly" do you mean that everything just going black or that you are having Kernel Panic's? > http://support.apple.com/kb/HT1392

If Kernel Panic, see > http://www.thexlab.com/faqs/kernelpanics.html

Also note: that in 10.5 Leopard the Disk Utility's Repair Disk Permissions messages that you are getting can be safely ignored. > http://support.apple.com/kb/TS1448

Reply

Answer 7

23degreesN Author

Level 1

0 points

Oct 13, 2010 12:06 PM in response to den.thed

Everything goes black, computer switches off instantly and I have to manually push the power switch in the back of the imac to boot up the machine again

Reply

Answer 8

den.thed

Level 9

76,858 points

Oct 13, 2010 12:50 PM in response to 23degreesN

Could be a loose/improperly seated or bad RAM module.

Reinstall the RAM, pushing firmly on each module with both thumbs to ensure they are fully seated.
Reinstall your factory RAM if you have upgraded with third party RAM.
If you have 2 modules, install one module a time and test.

See > http://support.apple.com/kb/ht1423

It could also be an overheating problem with any number of components, that is causing the iMac to shut down abruptly. If the Extended Apple Hardware Test does not catch the problem, then you will need to take it to an Authorized Service Provider for testing.

Reply

Answer 9

elmac

Level 5

4,252 points

Oct 13, 2010 1:29 PM in response to 23degreesN

Hi, are you using a Surge Protector?
Have you tried the Mac on a different power circuit?
Try a different power cord!
Have you downloaded any New Apps just prior to this Issue?...L

Reply

Answer 10

23degreesN Author

Level 1

0 points

Oct 13, 2010 6:51 PM in response to elmac

Yes I am using a surge protector. I have a diskstation server and modem also connected to the same surge protector with apparently no problem - I think it is stable

I reinstalled RAM but it seemed pretty well seated

Can anyone translate the report I posted earlier? Is there anything to be concerned about regarding the file count or damaged property lists?

Reply

Answer 11

Oct 15, 2010 12:00 AM in response to 23degreesN

Hi,

I am experiencing almost exactly the same problem as 23degreesN. When the computer is idle it will remain powered on but when applications are running (and it doesn't seem to be attributed to a particular application) it will randomly shut down with black screen and has to be manually restarted (although like some other posts it will always start straight away without problem)

In my energy saver settings I have 'Restart automatically after a power failure' unchecked which is probably why it doesn't automatically restart.

To try and resolve the problem I have done all that 23degreesN has done, I have also done a few things in addition:

I have used Diskwarrior (which was run from an external bootable hard-drive) to try and repair the computer. It completed the repairs successfully but the problem still remains.

I swapped the power cable from another iMac hoping that it might have been something as simple as a faulty cable. problem still remains.

Anyone out there with any ideas?

Reply

Answer 12

Oct 15, 2010 3:37 AM in response to .frustration.

continuing from my post above....

I have tried taking out the RAM, putting one back in, restarting - computer shuts down after 5 mins
and then replacing it with the other stick assuming that one may be faulty - again computer shuts down. Conclusion: I dont think the RAM is the problem unless both sticks are faulty

The only thing I can think of now is that the power pack in the computer is faulty but I am doubtful that this is the cause because if the computer remains idle (no applications running) it doesn't shutdown.

Reply

Answer 13

bressst

Level 1

0 points

Oct 15, 2010 2:57 PM in response to 23degreesN

Ok let me give you my thoughts after all the shutdowns I had on 2 iMacs 27:
I got my iMac 27 2.93 early september 2010. I made the upgrade to 16Gb (not have anytime to test the original 2x2 GB). I got many shutdowns. I call the support and made on my own all the following tests before calling them :
1 - Run the Techtool deluxe from Apple : everything was ok
2 - Reset the RAM : problem still there
3 - Reset SMC : problem still there
4 - Reinstall the OS from scratch on the internal 2nd drive (HDD instead of the SDD) : problem still there
5 - Deconnect all peripherals connected to the iMac : problem still there

It took 5 minutes to the Apple support to understand it was probably a hardware issue with the motherboard or an electrical issue. As it was less than 15 days I bought the mac, they send me a new one and got the old one after I received the new one (good service).

UNFORTUNATELY SAME ISSUES with the new one !!!!
Redo the same tests and same problems.
So I'm not sure about the interest for me to get a third delivery...
Reading all the threads, I conclude this is either a real hardware issue or a RAM issue because of the 16GB.
I just decreased the RAM to 12 GB yesterday and I will see....I'm pretty sure the problem will not occur. If confirmed I think we have no other choice to wait for an update unless the problem is a real hardware issue. I bought the apple care program so I can see within the next 3 years.
This is crazy not being able to use the 16 GB.
Feel free to give your thoughts.
Thanks

Reply

Answer 14

bressst

Level 1

0 points

Oct 19, 2010 3:17 PM in response to bressst

So far no shutdown after 4 days....

Reply

Answer 15

emilvals

Level 1

0 points

Oct 22, 2010 2:19 AM in response to bressst

Hello, I bought a new 27" iMac i7 last week. First problem I encountered and I am still encountering is random packetloss, I'm using a wired connection.

I also bought 16GB Ram from Macsales.com this week and installed it in the machine and this morning my iMac just completely shutdown like you are experiencing. 🙂 Hardware diagnostics don't find any problems.

Reply