Random iMac Restarts - how to track?

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Hi All,

In May of this year we purchased a new iMac (specs below) - my wife uses this computer and has told me that a message informs her that the computer 're-started' - now this has happen probably less than a half dozen times over the last 6 months or so. I've told her to keep tract of the programs she is using and let me see the messages, but these seem to be random events.

This has not really been a problem but I guess it could increase and become an issue? SO, I was just wondering what would be the best way for me to keep tract of these events? I re-boot the computer about once a month & I've tried to look @ the log records but they are too long & confusing (probably could use a tutorial). Any suggestions or comments would be appreciated. Thanks - Dave :)


iMac 21.5" display
OS X 10.9
2.9 GHz Intel Core i5
16 GB 1600 MHz DDR3
NVIDIA GeForce GT 650 M 512 MB
Fusion Drive 1 TB
 

pigoo3

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...my wife uses this computer and has told me that a message informs her that the computer 're-started'...

Can you elaborate? When does she see this message:

- while she is sitting in front of the computer?
- she walks away from it or 15-30 min (computer is not shutdown or in "sleep")...and returns...and the message is there?
- computer was shut down...then see's the message at the next reboot?
- computer was put to sleep...then she see's this message the next time she starts/wakes it up?
- Is this actually a "kernel panic"?
- Was the ram upgraded since purchase?

* Nick
 
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RadDave
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Can you elaborate? When does she see this message:

- while she is sitting in front of the computer?
- she walks away from it or 15-30 min (computer is not shutdown or in "sleep")...and returns...and the message is there?
- computer was shut down...then see's the message at the next reboot?
- computer was put to sleep...then she see's this message the next time she starts/wakes it up?
- Is this actually a "kernel panic"?
- Was the ram upgraded since purchase?

* Nick

Hi Nick - thanks for your quick response - I can answer a few of your questions, but not being there hampers a more thorough report - I've told her to keep better tract of these events and let me take a look when it does happen.

But, just a few comments: 1) RAM - I ordered the upgrade to 16 GB on initial purchase; 2) If by 'kernel panic' you mean the message (whatever color) w/ all of the languages - I don't believe that has ever occurred; 3) We only turn off the iMac when going on a trip, so it is on 24-7 and 'sleeps'; 4) Appears that she usually sees this message walking in to use the computer - may have occurred a couple of times using a program or two (does not seem to be consistent w/ anyone app). I'm assuming the image below (from the web) is what typically appears - probably suggesting a misbehaving app?

That's about all I can offer for now - again, this is a very minor annoyance that has not been disruptive in her use of the iMac - Dave :)


TS3742_01--Shut_Down-001-en.png
 
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Hello All - I started this thread late last year concerning 'spontaneous' reboots of our new iMac - my MBPro purchased a month earlier has never had this behavior - both came w/ Mtn Lion which I upgraded to Mavericks - well, her iMac went for a month or more w/o a reboot, then has now done it twice the last few days. Tonight I ran an AHT (Apple Hardware Test, i.e. a reboot w/ the D key held down) - completed in about 4 minutes and NO problems were found - NOW, I don't know how reliable this test may be in detecting a CPU, Memory, etc. problem but just assume that it is fairly accurate.

The messages seem to be the same as posted previously, i.e. the computer had to restart because of a 'problem' - never have gotten the multi-language dialog box, so not sure if these are indeed 'kernel panics' or something less minor? I've look @ multiple logs when these boxes pop up but have no idea what they mean. So, again just asking the best way to pursue this issue - any advice would be appreciated. Thanks - Dave
 

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Hi Dave:

Is her iMac hooked to an UPS? I'm sure where you live that the power is steady and clean, however, there are times when maybe glitches on the power line will occur. That can cause the machine to reboot. I keep my iMac on UPS at all times and there have been occasions where the UPS log shows that it went to battery for a given number of seconds. That was likely due to power glitches.

Another cause of random restarts is bad or intermittent memory. Since the memory modules on her machine are inaccessible, about the only way you can check on them is by the use of memory test software. You might want to give that a shot to see what it comes up with. Memory problems are probably a long shot on that machine since the modules are factory installed but you never know.
 
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Hi Dave:

Is her iMac hooked to an UPS? I'm sure where you live that the power is steady and clean, however, there are times when maybe glitches on the power line will occur. That can cause the machine to reboot. I keep my iMac on UPS at all times and there have been occasions where the UPS log shows that it went to battery for a given number of seconds. That was likely due to power glitches.

Hi Chscag - thanks for your quick response - I've used APC UPSs for years - our current one is shown below; we've had power go out several times (NC storms!) and the computer has stayed on fine to shut down - these events have happened when no storms were present, so not sure that is the problem?

Hi Dave:
Another cause of random restarts is bad or intermittent memory. Since the memory modules on her machine are inaccessible, about the only way you can check on them is by the use of memory test software. You might want to give that a shot to see what it comes up with. Memory problems are probably a long shot on that machine since the modules are factory installed but you never know.

Well, as stated I ran the ADT from boot up and it showed no problem, so I assume the memory modules are fine - but not sure how reliable the Apple test may be? Should I run some other independent software test the memory? Thanks again - Dave :)
.

APC.jpg
 

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Dave, my late 2007 iMac did that a few times. I was told to reset the PMU. The restarts stopped. Mine would do it at the worst times like in the middle of a game or middle of typing a letter.

Can not hurt to try.
 
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Dave, my late 2007 iMac did that a few times. I was told to reset the PMU. The restarts stopped. Mine would do it at the worst times like in the middle of a game or middle of typing a letter.

Can not hurt to try.

Hi Dennis - thanks for your response; NOW, I know about SCM & PRAM, but PMU is new to me - does this apply to iMac on AC or to laptops - just not sure?

Just for additional info concerning my issue, I just entered the Terminal of her iMac, and typed in 'last reboot' - below is the output - several of these reboots were done by me or the computer was turned off on short trips, BUT most are spontaneous reboots - just don't feel that this is normal activity, esp. considering that my MBPro has never really done this - confused? Dave :)
.

Screen Shot 2014-02-07 at 10.15.12 PM.png
 

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PMU is Power Management Controller. SMC should be the same. On my 2007 you power it down and pull out the power cord and hold power down 5 seconds then plug it back in. Your 21.5 might be different. It was restarting all the time and quite annoying and has never done it since that reset.
 
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Under warranty Dave take it back. Unusual problem all those reboots. Any chance the building power goes off randomly?
 
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PMU is Power Management Controller. SMC should be the same. On my 2007 you power it down and pull out the power cord and hold power down 5 seconds then plug it back in. Your 21.5 might be different. It was restarting all the time and quite annoying and has never done it since that reset.

Thanks Denis - well, I reset the SMC (directions HERE for Intel-based Macs) - will see what happens.

Under warranty Dave take it back. Unusual problem all those reboots. Any chance the building power goes off randomly?

Thanks Harry - I'll wait a few weeks to see if the above helps; if not, the computer was purchased locally at Mac Authority - I'll give them a call - it's still under first year warranty (and has Apple Care). Dave :)
 

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