iMac has begun to reboot

HI, I have an iMac 27" display that is about 2 years old. The configuration is as follows: 3.4 GHz Intel Core i7, 32GB RAM, NVIDA GeForce GTX 680MX 2048MB graphics card and I'm running OS X Yosemite v10.10.2. I'm running Norton AntiVirus 360 and my virus signatures files are updated.

I've noticed a strange issue lately where my Mac will reboot overnight. It will also begin to slow down a bit and shut down Safari suddenly. - This happens mostly when I'm on eBay.  I've begun to us eBay more often lately because I'm restoring an old car and I'm looking for parts, so I spend a lot of time on eBay now as apposed to before where I visited eBay maybe once in a long while. -- I have not noticed this symptom with any other application or website.

Could the reboots have anything to do with eBay? If so, what is it and how do I resolve it - (other than not using eBay).

Thank you,
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Christopher Jay WolffConnect With a Mentor Wiggle My Legs, OwnerCommented:
Stories like yours and Norton is often the culprit.  Bitdefender for mac gets high marks.  Please note these historical Norton issues from Macworld, even though they are not 360.  I believe it is a reflection of design and way of thinking.

Prior to doing these procedures please make sure your data is backed up, and you read the concerns outlined in the article about settings you'll lose like for boot drives, if you have a RAID set up or something.

-uninstall Norton 360

-Reset PRAM
reboot mac and immediately hold Shift Opt P R, keep holding after boot chime, then it will reset and you'll hear the boot chime again, then you can let go.  described here..

-Reset SMC
Procedure to reset the SMC for your mac by holding power key down for more than 5 seconds.  First disconnect power and remove your battery.

-Clear cache everywhere you can think of like DNS and Skype.  To clear DNS cache the procedure is to use Terminal as described here.

-Reset your browser by dumping all cookies and browsing history and caches and databases.  The only thing you might keep is bookmarks.  Or if comfy with reset of all then do that.

Now run something like Bitdefender and Apple's Disk Utility.  DU is in Applications/Utilities.  You would want to run First Aid.  Verify only.  If no errors great if errors have to decide best repair.  Usually if HDD is backed up, then let repairs be made by First Aid.

That's a lot of time so we all might do more depending on how you do with this.  I hope it is helpful.
Christopher Jay WolffWiggle My Legs, OwnerCommented:
and I wanted to mention a bootable backup is helpful and procedure is here

and if using Firefox or other try Safari for reliability issues until this is solved.  Obviously if you're trying to pinpoint what did it, please try one thing at a time.
Christopher Jay WolffWiggle My Legs, OwnerCommented:
Also check power cord connection on back center.  Make sure when cord is removed that the three-pronged inner receptacle is not loose in it's mount inside the computer.  Sometimes it is easier to tell if you plug the cord back in and use the molded end as a handle to try and feel a loose wiggly connection inside the machine.  This same check should be done down the line if you then go to surge protector and then to wall outlet.
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Mr_FulanoAuthor Commented:
Hi Christopher, first and foremost, thank you for all the time you spent explaining the different steps. - The only concern I have with doing this is I'd have to uninstall Norton 360. I've been using Norton 360 for years and never had an issue like what I'm experiencing now. In fact, the only thing I can correlate to the problem is eBay. Why would I need to uninstall Norton and move over to another type of antivirus software to resolve the issue?

Christopher Jay WolffWiggle My Legs, OwnerCommented:
You may not have to, it is just the way I would do it.  Lots of ways to do things. I wasn't trying to say you have to give up Norton to resolve the issue.  I was trying to say, if it were me, I would uninstall Norton to reduce my variables, and was trying to suggest I would prefer BitDefender or Kaspersky or other.   I wonder if you read the complaints highlighted at each of two MacWorld links above about "uninstallNorton" as they sound glitchy like your problem, and I've had this type of thing come up with Norton in my life elsewhere in the last few years.  When I started out with Norton Utilities for PCs back in the 80's it was "THE" tool for serious techies that needed reliability.  The last time I bought it for myself a few years ago, I had lots of reliability problems, and I returned it.  I understand they've come a long way back however.

So you could skip the uninstall Norton part if you want, especially if you've had no problems for the two years you've had the Mac and it was running.  But the reason you may want to do it, is it may be the first time you have exercised Norton by actually getting attacked and trying to survive and remediate an attack of browser hijacking or worse from the ebay site.  So it is still something to consider.  At least with respect to uninstalling it for testing purposes since a part of it may have gotten corrupted, then getting a fresh install of it if you decide to stay with it.

In your original post you mentioned "mostly when I'm on ebay" so I was thinking in broader terms than your more recent post stating "the only thing I can correlate to the problem is ebay."  So when it reboots during the night is the browser open and viewing ebay?
strungConnect With a Mentor Commented:
Check the console logs for the when Safari quits and also immediately before the reboot. Check the console crash reporter as well.
serialbandConnect With a Mentor Commented:
It most likely is a web page that's causing a crash, mostly likely some ad/spammer pages included on the page.

Some suggestions to mitigate the problem:

Don't leave yourself logged in to web sites.  Quit browsers or close problem pages.  They all have scripting and some pages are programmed by fresh out of college amateurs that have little experience with memory leaks.  Your system likely slows down because of one of the pages' runaway process.  Close that page and all will be well.

I suggest Firefox, Chrome, Chrome Canary, or Opera Next instead of Safari..  They let you close the page, temporarily unloading it, then reload it with Command Shift T (for a closed tab) or additionally with Firefox  Command Shift N (for a closed window)   For all the others (Chrome Clones) You need to go to history and find the Recently closed window.  That way the scripts on that page unload and doesn't stay running, and you can go right back to what you had previously loaded, assuming it's not a banking page the forces a timeout.

You can periodically run purge on the terminal command prompt to clear unused RAM and speed up your system.  You should find the page that's causing problems, since purge is just a stopgap.  You can avoid system problems,  scams, and cross site scripting by turning off plugins during normal browsing and installing Adblock, flashblock, and noscript to prevent initial infections in the first place.  Don't use Safari.  It doesn't have as many capable add-ons and they've started conforming to the Clear History and Website Data function instead of a full reset of everything.

You can run multiple browsers to keep work, banking, and other personal sites separate, so that there's no leakage of information.  If you want to reload pages where you left off, there's session managers that will let you reload previous sessions.

I suggest switching AV, if Norton AV turns out to be the culprit.  There are plenty of capable AV to run on the Mac and several of them are free.,review-2588-6.html

The majority of AV for Mac scans for Windows viruses to keep them from spreading to windows users.   Uninstalling Norton won't hurt you short term.  There are very few viruses for Mac at this moment in time, but that will change when Macs become more prevalent.  There have been a few proof of concept exploits and a couple of actual attacks, but those have been quickly shut down, so far.  There aren't any known viruses for the Mac that are currently running at this moment.  Some day, if Macs reach critical numbers, you'll have to run AV to actually protect the Mac, but current Mac AV is mainly run to protect Windows users by reducing the spread of viruses to them.
Christopher Jay WolffWiggle My Legs, OwnerCommented:
And of course if you elect to stay with Safari for familiarity or other reasons, they have methods outlined at the following link to remove ebay specific, and other ad-injection malware.  They will also help anyone whose Mac is less than 6 years old eliminate ad and spam related problems for free.   You may also launch Safari holding the shift key to prevent ad related software from loading, but you may lose something you want.  Maybe that's okay while fixing your car.  I better go fix mine.
Mr_FulanoAuthor Commented:
Thank you all for your suggestions. I will look further into this matter this week and close this question out no later than next week. Thank you!
Mr_FulanoAuthor Commented:
Gentlemen, please excuse the delay. I have been away on business and have not had the chance to devote more time to this post. I also wanted to give the computer some time between teaks to see what responses I would have.

In the end, I'm not sure what the solution was or if its even resolved at all. I know that the iMac was rebooting even when I didn't visit eBay. I left it running for 4 days while away on business and it rebooted on day one. I also know that I often experienced a shutdown of Safari when I was on eBay for too long (over an hour). The machine did not reboot, just a Safari would close.

What I did that seems to have made it stop was to factory reset the Norton Firewall settings. I think I may have had a corrupt firewall setting that made the machine crash -- that's just a guess, but its has stopped rebooting on its own after that.

I'm going to split the points as evenly as I can, because I think you ALL helped. Thank you very much for all your great advice!

Mr_FulanoAuthor Commented:
EXCELLENT assistance. Very thoughtful and detailed help on this problem. Thank you to all.
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