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User profile for user: beischel
beischel Author
User level: Level 1
6 points

Mid-2011 iMac locking up

Folks, almost every day I experience the iMac locking up requiring cycling the power to reboot. I checked the log from the console each time it happens and this is what I am seeing around the time it locks up. It references "slot 1" but not sure if this is related to memory. I have run several memory test using memtest and rember and the memory always passes. Any suggestions on what is happening and what to do would be most appreciated.


Here is a sample of the console log message:


6/28/12 11:26:13.000 AM kernel: IOSurface: buffer allocation size is zero

6/28/12 11:26:13.000 AM kernel: IOSurface: buffer allocation size is zero

6/28/12 11:26:19.000 AM kernel: IOSurface: buffer allocation size is zero

6/28/12 11:26:19.000 AM kernel: IOSurface: buffer allocation size is zero

6/28/12 11:27:02.000 AM kernel: IOSurface: buffer allocation size is zero

6/28/12 11:27:02.000 AM kernel: IOSurface: buffer allocation size is zero

6/28/12 11:27:04.000 AM kernel: IOSurface: buffer allocation size is zero

6/28/12 11:27:30.000 AM kernel: ** Device in slot: SLOT--1 **

6/28/12 11:27:30.000 AM kernel: ** GPU Debug Info Start **

6/28/12 11:27:30.000 AM kernel: 0x00006741

6/28/12 11:27:30.000 AM kernel: 0x0000008f

6/28/12 11:27:30.000 AM kernel: 0x00000001

6/28/12 11:27:30.000 AM kernel: 0x00000018

6/28/12 11:27:30.000 AM kernel: 0x0000a880

6/28/12 11:27:30.000 AM kernel: 0x00000001

6/28/12 11:27:30.000 AM kernel: 0x00000001

6/28/12 11:27:30.000 AM kernel: 0x00006741

6/28/12 11:27:30.000 AM kernel: 0x00000001

6/28/12 11:27:30.000 AM kernel: 0x00000015

6/28/12 11:27:30.000 AM kernel: 0x00000000

6/28/12 11:27:30.000 AM kernel: 0x00000001

6/28/12 11:27:30.000 AM kernel: 0x00000047

6/28/12 11:27:30.000 AM kernel: 0x00000000

6/28/12 11:27:30.000 AM kernel: 0x00000001

6/28/12 11:27:30.000 AM kernel: 0x00000058

6/28/12 11:27:30.000 AM kernel: 0x00000012

6/28/12 11:27:30.000 AM kernel: 0x00000001

6/28/12 11:27:30.000 AM kernel: 0x00000055

6/28/12 11:27:30.000 AM kernel: 0x00000000

6/28/12 11:27:30.000 AM kernel: 0x00000001


The kernel messages go on and on so only pasted the first part of it.


Thanks again for any help.


Duffy

iMac (21.5-inch Mid 2011)

Posted on Jun 28, 2012 8:39 AM

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3 replies
User profile for user: BDAqua
BDAqua
User level: Level 10
239,111 points

Jun 28, 2012 11:15 AM in response to beischel

Hi Duffy,


My guess is the Video card.


At the Apple Icon at top left>About this Mac.


Then click on System Report>Hardware>Graphics/Displays and report like this...


NVIDIA GeForce 7800GT:


Chipset Model: GeForce 7800GT

Type: Display

Bus: PCI

Slot: SLOT-1

VRAM (Total): 256 MB


Have you blown the dust out lately? Let it cool for an hour & see if you can get these...


Get Temperature Monitor to see if it's heat related...


http://www.macupdate.com/info.php/id/12381/temperature-monitor


iStat Menus...


http://bjango.com/mac/istatmenus/


And/or iStat Pro...


http://www.islayer.com/apps/istatpro/

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User profile for user: beischel
beischel Author
User level: Level 1
6 points

Jun 29, 2012 3:59 AM in response to BDAqua

Yes, I blow the dust out about once a week.


The temperature of the card is around 130F on the GPU Diode and 124F on the GPU heatsink.


I can restart right away and it will continue working. I do not believe it is a heat issue.


Not to mention, since I have had this system, I have a fan blowing on the back of the monitor area to help disapate the heat.


I did go to the system report on the graphics card, and there is nothing there that indicates the graphics card is in slot 1.


Thanks,


Duffy

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Mid-2011 iMac locking up

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