Late 2010 Core i7 iMac Shutdown

Have you already applied the latest software updates including the Snow Leopard Graphics Update 1.0?

If you have the latest 27” iMac with the new ATI 5750 graphics processing unit with 1 GB GDDR5 graphics memory, this must be discouraging. Call Apple about your problems as engineering will be very interested in knowing about problems with the latest and greatest.

It seems to me you may have two unrelated problems related to graphics and your external drive connection. Have you experienced the black screen/shutdown with no external drives connected? How are you connecting the external drives?

Actually you may have more than a graphics problem if the machine is abruptly shutdown. That may not be a graphics problem at all but a fault in the power supply or logic board. Why do you think Facebook is causing your machine to shutdown? Are you primarily handling photos while in Facebook?

If you want to get be prepared when you call Apple, there are three standard things you can do to see if the problem still persists: reset the NVRAM (also called resetting the PRAM); reset the SMC; and an Apple Hardware Test.

To reset the NVRAM on your new machine:
1) shutdown the computer,
2) as soon as you hit the power button, hold down the OPTION, COMMAND, P, and R keys until you hear the computer startup chime twice - resetting the NVRAM causes the machine to go through it’s initial boot sequence twice.

To reset the SMC:
1) shutdown the computer,
2) unplug the computer,
3) hold the power button down for at least five seconds,
4) plug in the computer,
5) hit the power button to start the computer.

To do the Apple Hardware Test (AHT):
1) load the Application Install DVD in your optical drive.
2) shutdown the computer,
3) as soon as you hit the power button to start the computer, hold down the H key - this causes the computer to boot into the Apple Hardware Test. You should be able to function with your wireless Magic Mouse but you may need to use a wired USB mouse if the mouse is not responding once you are in the AHT. Select the “extended” hardware test and be prepared to wait about two hours for the test to complete. It may well come back with “no problems found” but that’s good news when you call Apple about your difficulty.

Message was edited by: Rick Lang

I'd start by running Apple Hardware Test. Sounds like you may have a bad logic board. If you call Apple, odds are they're going to want you to run AHT anyway, so you may as well get it out of the way and save yourself some time on the phone.

Add me to the list.

I got my iMac 27" i7 about two weeks ago. It ran fine up until this past week end. Over the week end it locked up about 4 or 5 times. Each time requiring me to hold the power button to reboot.

I have not installed the new graphics update. Will do that later today. Hopefully it will help.

Message was edited by: Fender5900

I trust you mean while you wait for the RMA replacement RAM to arrive, because you shouldn't be letting someone get away with selling you bad RAM.

I'm having the same problem as well on the same hardware.

I bought the new iMac a few weeks ago (27" i7). I purchased 16GB RAM from OWC at the same time. About a week after having the new iMac I installed the video driver update. Since that update my Mac shuts down at random times (sometimes multiple times a day). It doesn't seem to matter what I'm doing: I could be doing some development work in Eclipse or just browsing the web with a web browser when it shuts down (Safari, Chrome, Firefox... it's crashed with all of them).

After rebooting, if I check the system logs there is nothing there. One minute I see standard logs from whatever program I'm using, then nothing. The next thing in the log I see are standard bootup logs and a message about an incorrect shutdown.

The video driver could be a coincidence since I only had the new iMac for a week. So I'm up in arms. I'll try some of your suggestions though and maybe see if I can find a memory testing program out there.

Hi everyone,

I don't think is a bad RAM issue.
Could it be Apple firmware issue with latest iMac that can't support 16GB well?

I personally came across similar problem mentioned by Sjohnson803, Jeff.C & MaconMatt at http://discussions.apple.com/thread.jspa?threadID=2567543&tstart=30

I posted at http://discussions.apple.com/thread.jspa?threadID=2567907&tstart=15.

A helpful guy, den.thed, suggested me to buy at OWC but Jeff.C & Sjohnson803 got 16GB from OWC & they are facing similar problem too.

So far tested on 2 units of iMac 2010 (27", i7) & a unit of iMac 2010 (27", i5) with 16GB, all 3 sets having kernel panic shutdown issues.
Tested 2 different brands of memory also ended with similar problem.

One iMac (27",i7) returned back to Apple, now left a iMac 27" i7 & iMac 27"i5 running with 8GB (regardless 2X4GB or 4X2GB) all without issue.

What you guys think?

I'm having the same issues...

http://discussions.apple.com/messageview.jspa?messageID=12254136&stqc=true

Purchased 16GB RAM from OWC, unfortunatley I'm on iMac #4 (2 bad screens and the latest one just won't take the 16GB, kernel panics, hung on start up)

The very first iMac I had (with the dead pixels) has happily been running the OWC 16 GB for 2 weeks no issues, I've AHT'd all the DIMMS in pairs and all 4 together and they pass.

Strange thing is SMC & BOOT version are the same...

I purchased memtest and ran it's full diagnostics which all passed on the 16GB of RAM. I used Mac's hardware test software in extended mode which passed (while in single user mode). Then I brought the RAM down from 16GB to 8GB and ran that for a few days and found no problems (I also tried the original 4GB of RAM from Apple for a couple days with no problems).

I spoke with Apple Care and went through all the same hoops. Eventually it was escalated to a higher support level. I got in touch with this great support guy who brought the issue to the eyes of engineering (who at the time had not heard of this issue). I gave them the link to this thread as well as a couple others all having the same issue.

At this moment I am about to reformat my Mac (for other reasons not related) and will continue to run on 8GB.

My question to others: When I received my new iMac (27" Core i7 with 8GB RAM (from OWC)) I had it running for a couple days with no problem. Then the recent video driver update came out (to help improve things like Valve's video game suite) and the next day I started having the shutdown problems (and bootup problems after a kernel attack). Does anyone know if they were having this issue BEFORE the video driver update? I'm just wondering if it is related (it could be coincidence since I only had my new iMac for a couple days before the video driver update). I'm thinking of maybe not installing the video driver update (after I reformat) while running on 16GB for a few days to see if the issue happens.

Hi TheAnimist,

Am I right to say that your first iMac, claimed to be working fine with 16GB, identifier is iMac11,1 & RAM speed (1066Mhz)?

Is your problematic iMac identifier iMac11,3?

New iMac 2010 identifier should be iMac11,2 & iMac11,3 & RAM speed 1333Mhz.

Thats the weird thing, they have all been identical, and only the very first one has worked out of the box. I've system profiled each of them to vrify same SMC/BOOT, iMac #1 16GB no problem (this one came from China), the next 2 (from Cork/Dublin) just panic/display weird screen things/hang)... It's very strange!

Hardware Overview:

Model Name: iMac
Model Identifier: iMac11,3
Processor Name: Intel Core i7
Processor Speed: 2.93 GHz
Number Of Processors: 1
Total Number Of Cores: 4
L2 Cache (per core): 256 KB
L3 Cache: 8 MB
Memory: 16 GB
Processor Interconnect Speed: 4.8 GT/s
Boot ROM Version: IM112.0057.B00
SMC Version (system): 1.59f2

And memory info :

ECC: Disabled

BANK 0/DIMM0:

Size: 4 GB
Type: DDR3
Speed: 1333 MHz
Status: OK
Manufacturer: 0x80CE
Part Number: 0x4D34373142353237334348302D4348392020


BANK 1/DIMM0:

Size: 4 GB
Type: DDR3
Speed: 1333 MHz
Status: OK
Manufacturer: 0x80CE
Part Number: 0x4D34373142353237334348302D4348392020


BANK 0/DIMM1:

Size: 4 GB
Type: DDR3
Speed: 1333 MHz
Status: OK
Manufacturer: 0x80CE
Part Number: 0x4D34373142353237334348302D4348392020


BANK 1/DIMM1:

Size: 4 GB
Type: DDR3
Speed: 1333 MHz
Status: OK
Manufacturer: 0x80CE
Part Number: 0x4D34373142353237334348302D4348392020

Add me to this list. 27" iMac but with Quad i5. I have been experiencing spontaneous shut downs. At first it seemed to be due to high load but now it's with web surfing or code editing. I had upgraded to 16 GB from OWC but have now reverted to the original 4GB. I really didn't notice an issue until the 10.6.4 upgrade but I didn't have the machine at 10.6.3 very long. I'm curious to see how this turns out....

I've run 24+ hrs with some pretty intensive tasks at 12GB installed w/o issue. I'm thinking there may be an issue w/ 16GB in these machines.

I'm having the same issue.

I just got my Imac i7 this past Wednesday, upgraded it to 16 gigs as well, and it has been randomly shutting down as well. Yesterday it shut down within a 4 hour span 5 times.. I really hope this gets fixed.