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My Mac Pro spontaneously restarts

147734 Views 471 Replies Latest reply: Apr 5, 2014 8:05 PM by zeratulok RSS Branched to a new discussion.
  • 3PIXELS Calculating status...
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    Dec 19, 2011 10:25 PM (in response to Bruce Siegel)

    Thanks for the link. Will check it out.


    You want to have both risers working in a perfect world.


    There's a reason for this. Apple design the Mac Pro as we all know for serious processing punch.

    You might not see a huge difference with one riser operating on launching apps or doing basic jobs.

    However when rendering or submitting a job for conversion in compressor you will see a decrease.


    When you have pairs installed on 2 risers as apple recomends you have dual access to the total memory at the same time.


    For lack of a better explanation, imagine you have fans trying to get get into a football game at a stadium.

    Option A is they all access the stadium parking through one single lane road. Option B is there is a dual-carriage way or double lane. Logically more cars could access the stadium using a double lane road at one time.


    The stadium parking size remains the same (total memory installed) but giving them 2 ways to access it would get the cars in and out faster.

  • Bruce Siegel Calculating status...
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    Dec 20, 2011 8:03 PM (in response to 3PIXELS)

    Thanks, Stephen!

  • plainhat Calculating status...
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    Jan 19, 2012 8:24 PM (in response to jrbuuck)

    OK, I'm climbing on board here.


    Mac Pro 3.1, 2 Quad Intel Xeon, 2.8, Early 2008, only the original 2 GB out of the box RAM on board. I got burnt just a year out with the machine when the vid card went (no applecare..yes, I've learned that lesson) before they finally recalled them. 


    After that, things seemed ok until the odd random reboot starting last fall. The power in this house is a bit hinky so I chalked it up to that and a monitor that was failing (see below). But in the last few weeks they happened more often. Tonight I got the first spate of multiple serial reboots.


    After reading through all of this thread (long read!) I've adjusted my energy saver (that has at least halted the serial reboot fail reboot fail problem) and this weekend I will tackle the long overdue cleaning. Then I'll call an old Mac geek friend and ask for help checking risers (honestly, I wouldn't know how to begin ) . 


    Anyway, here's a possible clue or two about the possible power issues:

    1. Right after the very first random reboot, the smaller of my two monitors went feet up. It was old, but at the time I kind of wondered if its impending demise didn't provoke some power issue for the machine.
    2. It was last fall that I got a new HP Printer. At first I was using it wirelessly, but had HP related issues with that so finally I used the USB. It was after that the real trouble first started.
    3. I use my USB ports to charge (ahem) my electronic cigarette batteries. Just when all this started ramp up, one of the chargers seemed to stop working. It was indicating that it wasn't charging. Oddly, it worked on my MacPro at work and in the outlet adapter.


    Oh yeah, and I also have a wacom plugged in...all of which makes me wonder if it isn't a power supply problem or something amiss with the USB setup.


    Either way, my next trip (after checking the risers) will be to get a UPS and see if that doesn't help.


    Honestly, I was a PC convert. This was my first (may be my last) Mac. I bought it because it was the first time Mac had a machine for which I couldn't build the equivelent for myself more cheaply. Hmmmmm maybe there was a reason for that. As others said, I'm not sure that short of four years is all I should expect for $2500.00 (plus replaced video card). I absolutely can't afford a new Mac now so if this goes feet up I'm going to be forced to return to PC land. Not that it will make me happy!


    Thanks for all the good folk responding here. At least there is a chance we know what the problem may be!

  • mdavidsydney Level 1 Level 1 (75 points)
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    Jan 19, 2012 8:54 PM (in response to jrbuuck)

    Thanks for the post, plainhat.


    Well, after getting several random restarts in a single day I've now gone almost 3 months without any random restarts. Well okay, I've had one but I'll get to that in a moment.


    I followed the advice given earlier which was to:

    1. switch computer off, unplug power lead from back of Mac and hold power button down for 10 seconds
    2. plug lead back in, turn on Mac and zap the PRAM
    3. go to energy saver prefs and click the restore defaults button, and then set the computer sleep to 'never'


    That did it.


    About a month ago my computer spat out its DVD tray during a startup and I've learned that in my case it means the random reboot thing is going to start happening again. Don't ask me why. I know it sounds more like voodoo than science/logic but that's how it is with my Mac and a weird warning is better than no warning at all. Sure enough, it did a random restart about 2 hours later. So I did the 3 steps described above again and it's been no problems since then.


    I too have an early 2008 Mac Pro. Disappointing that I can't allow it to sleep any more, but at least I can rely on it again.

  • dwight w. Level 1 Level 1 (0 points)
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    Jan 19, 2012 9:13 PM (in response to mdavidsydney)

    I spent dozens of hours over a period of months reading and trying suggestions. Power management, zapping pram, taking out and reseating ram, UPS, different power outlets, disconnecting USB devices, removing hard drives, starting up with different versions of the OS, with various degrees of success. Things would work for a while and then I would get up one morning, try to start up and watch the computer (early 2006) start to cycle over and over. Trying to put the computer to sleep caused shut down.


    I strongly suggest trying a new power supply. You can pick them up for $250 or sometimes much less on eBay. They are easy to install, and it solved all my problems, and the computer has been working perfectly for two months--including sleep.


    I don't know how the power supply can cause such mysterious and unpredictable problems--or how the various "solutions" can work for a while--but it does.

  • Agentfruit Level 1 Level 1 (0 points)
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    Jan 19, 2012 10:39 PM (in response to jrbuuck)

    Hello all


    I think I have the dubious honour if having the 'worst' problem early 2008 MacPro here....I posted to say that mine had gone through all the sleep wake cycles, progressing to more bizarre behaviour leading to temporary fixes after unplugging for several days, progressing to total failure.....only small murmurs for a nanosecond when the power button was pressed.


    I cleaned the risers etc and was about to relegate the machine to doorstop status thinking it must be the the logic board, but as one last stop took the machine to Apple. Contrary to people's experiences on here they had a very simple diagnostic test specific to this machine involving a long stick poked in under the riser board to where there is a tiny button and row LED's. When pressed the resulting LED pattern that lights up diagnoses the problem in the machine. The result?.....Power suppy.


    I didn't believe it as the Apple Genius had never actually seen a MacPro and was working from a manual (!) and I told him that I thought the risers were more likely. They replaced the power supply for £160 and it's been on test for 5 days with no problems so far. I've spoken to them and they've put it through its paces in every way possible, day and night.


    So, fingers crossed, one totally dead MacPro, classic sleep wake cycle issues gone terminal, seems to have proved that it's power supply. I urge you to try it. Applestore Genius bars sell reconditioned ones for £160 including fitting and 3 months warranty.



  • cakesson Calculating status...
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    Jan 24, 2012 11:26 PM (in response to jrbuuck)

    I too have gone back and forth with this issue for a long time. For me, I have eliminated software suspicions since it still happens when pulling the Mac HD and putting in a Win 7 and running from that. I took it into the Apple store where it ran completely fine in both OSX and win 7. I then assumed faulty surge protector and bought a good UPS. Ran fine for a while and then it started happening again.


    I am going to try all other things suggested and tried in this thread (it's a great resource by now).

    Six not having a reliable computer (iPad ties me over with the simple things, and is reboot free :))


    I do think that Apple needs to acknowledge these issues and put up a FAQ....

    2008 MacPro (3.1), Mac OS X (10.6.4), Windows 7 64 bit (bootcamp), 14 GB RAM
  • Agentfruit Level 1 Level 1 (0 points)
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    Jan 25, 2012 12:50 AM (in response to cakesson)

    Hi Cakesson

    Did Apple do the diagnostic test with the LED's inside the machine? That was the instant answer to what wasn't working properly. My machine used to run fine for days at a time before it died completely, so my inclination would be to spend the relatively small amount of cash on a reconditioned power supply fitted by an Apple Genius bar. I asked them what would happen if it proved not to have been the problem after all and they said they would refund my money.

    So do your negotiating, have it changed, make them test it for five days minimum on every energy saver setting imaginable, and see what happens.


  • Sukiari Calculating status...
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    Feb 6, 2012 9:22 PM (in response to Ziatron)

    This is not a tenable possibility.  Firstly, smart meters only started making it onto the market in the last two years.  Second, I don't think the power company cares how much power you use - they charge more and more, the more you use.  Third, I don't think consumer electronics have smart meter chips that allow anybody to remotely shut them down.

  • cakesson Level 1 Level 1 (0 points)
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    Feb 7, 2012 8:42 AM (in response to Agentfruit)

    Hi all,


    Thanks for the reply Agentfruit.

    I took the MP to work (Sony) to see if the issue happened here to and it did...


    Brought it to the Apple store again and this time they could reproduce the shut down issue and diagnose it. I turned it in. They installed a new power supply for a total cost of $204. It is now running as stable as ever and the issue is completely gone.


    I will side with Agentfruit and say if you can, throw down for a new power supply through Apple if you are experiencing similar symptoms. I think it's just a matter of time if the issue shows up intermittently in the beginning and it will likely progress to not fully booting at all.



  • Sukiari Level 1 Level 1 (0 points)
    Currently Being Moderated
    Feb 7, 2012 10:59 PM (in response to cakesson)

    I have had the spontaneous restart issue for the past month or so.


    I figured out a solution that works for me.  I downloaded a program called smcFanControl and set it to always run my fans at 1400 RPM.  My computer is now stable with this quick fix, which leads me to believe that Apple / Intel has an undiagnosed or unrecognized thermal issue.


    Anyway, it's something for others here to try.  Good luck.

  • William Kucharski Level 6 Level 6 (14,405 points)
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    Feb 7, 2012 11:33 PM (in response to Sukiari)

    Not necessarily; you may have a hardware component that is more sensitive to heat than it should be, which is often an early sign of a component failure.


    If you have AppleCare, you should take your machine in for further diagnosis.

  • Agentfruit Level 1 Level 1 (0 points)
    Currently Being Moderated
    Feb 8, 2012 1:07 AM (in response to William Kucharski)

    I agree William and Cakesson. I had temporary fixes early on, thinking I'd 'solved' it. However if you stand back from the problem and this discussion there's one common theme......lots of temporary fixes, compromises and subsequent failures. What people seem to be overlooking is the fact there's a very simple and, it seems unknown, row of diagnostic LED's inside the riser board bay. It's inaccessible unless you know it's there an you need Apple's manual to interpret the results, but it gave us an instant diagnosis of what the problem was. It may be that the problem recurrs of course, however the machine has been running for a week so far, with energy saver on, and it hasn't shown any signs of misbehaving so far. Bear in mind that it had got to the point where it wouldn't start up at all when I took it in.


    So I'd strongly suggest that everyone here pays a FREE visit to a Genius Bar at their local Applestore, ask them to do the LED diagnostic test, and see if it shows anything up. What's to lose except a few quid/dollars worth of fuel?



  • Agentfruit Level 1 Level 1 (0 points)
    Currently Being Moderated
    Feb 8, 2012 1:10 AM (in response to Agentfruit)

    Ps .....and before you say "but my MacPro is very heavy", they carried it to and from my car for me too!

  • Sukiari Level 1 Level 1 (0 points)
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    Feb 8, 2012 2:01 PM (in response to William Kucharski)

    Applecare would have run out on this machine.  It's a 2008 Mac Pro.


    Here's the deal though - many, MANY people are reporting issues with their Mac Pros, with the sudden shutdown issue.  I do know that there is a thermal sensor built into many Intel products, that will kill the power completely if there is an overheating issue.


    Couple this with the fact that many of the people (including myself) who report these thermal issues, also report that after leaving the computer off overnight or for a few hours, are able to get it to boot and work again.  People are also reporting the same problem eventually occurring again after their computers are repaired with the typical fixes - logic board or power supply.


    I do not believe that this many people have had component failure without a triggering issue - such as years of overheating because of inadequate cooling.  Believe what you wish, of course, but my problems are gone since I have been keeping the fans on at a higher RPM than the system normally would.  I hope others with the same issue would download and try smcFanControl to see if this really will help them too.  If it does, I would wager we have nailed down the issue.

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