Macpro restarts when bumped

Discussion in 'Mac Pro' started by adamzx3, Feb 26, 2009.

  1. adamzx3 macrumors regular


    Sep 8, 2007
    NE Ohio
    Is this normal? :confused: if I accidently kick/bump it with my shoe, it will instantly restart.
  2. Tallest Skil macrumors P6

    Tallest Skil

    Aug 13, 2006
    1 Geostationary Tower Plaza
    Yes, that's normal. It's the Sudden Kicking Sensor doing its job...:rolleyes:

    Open it up (WHILE IT'S OFF) and check all the connections of RAM (DIMMs on risers and the risers themselves), HDDs, and PCIe cards.
  3. opeter macrumors 65816


    Aug 5, 2007
    Slovenia, EU
    Well, you shouldn't kick your Mac Pro. I think it's quite obvious.
  4. Cryptic1911 macrumors member

    Mar 11, 2008
    something is loose.. check all the connections inside, and also the power plug
  5. adamzx3 thread starter macrumors regular


    Sep 8, 2007
    NE Ohio
    Haha :D

    It wasnt real a kick, I just tagged it while getting out of my desk.

    I'll check it over, thanks!
  6. rylin macrumors 6502

    Aug 18, 2006
    It's nice to see someone thinking for a change! :)

    Loose chips would mean kernel panic, not reboot.
    A glitchy PS would reboot.
  7. nanofrog macrumors G4

    May 6, 2008
    A loose chip, and it may not reboot at all, depending on which one. :p

    BTW, is the spring on the power switch broken?
    (I don't know if it's one[internal to actual switch] or two [additional spring load on aluminum push button]). :confused:
  8. synth3tik macrumors 68040


    Oct 11, 2006
    Minneapolis, MN
    nanofrog brings up a good point. I have not had problems with the power button on my Mac Pro, but my MBP once was constantly rebooting. I finally saw that the spring in the power button was broken and the button had slipped inside the case, therefor making the computer think that the power button was being held down.
  9. Macpropro80 macrumors 6502

    Jan 31, 2009
    lol this has got to be the funniest problem I have ever read. If this was a pc it would read, I bumped my pc and it exploded and now it wont boot, and is on fire. ;) :apple:
  10. tom. macrumors 6502


    Nov 9, 2007
    Try and insert a hard drive into a Mac Pro while it is turned on. A lose connection on some hardware can cause a short and make the PSU cut out and reboot the machine. I wouldn't immediately assume kernel panic, especially for something with high power consumption like a hard drive.
  11. nanofrog macrumors G4

    May 6, 2008
    A single HDD doesn't use that much power. Typically 36-40W (peak) at spin up. Then drops to ~12W, less on some of the newer drives. So it shouldn't be like a dead short to the PSU.

    Trying that with multiple graphics cards, might be another story. :eek: ;) :p
  12. gto47 macrumors newbie

    Mar 11, 2009
    Okay, I think that I have some insight on this problem. I have a mac pro dual quad 2.8. It is situated on extra large old executive desk with the mac pro rotated sideways to give me lots of room to work.

    I started noticing the same problem when i close the desk drawer too quickly. The drawer opens and closes directly beneath the computer. I did basic troubleshooting, unplugged everything and used wall outlets instead of going through a power strip. Nothing worked, if i closed the drawer in the right way, it would reboot or freeze every time.

    Here is where it gets interesting. When moving everything around, I unplugged my lamp and noticed that a bright red light would illuminate at the back of the case to the left of the IO panel. Googling this brought up that the lights actually indicate memory status in the riser ram cards.

    If you open the case from the access door you can see just how far these riser cards stick out. They nearly touch the side of the door.
    I believe that the opening and closing of the desk drawer causes a vibration of the access door which in turn bangs on the memory riser cards, causing lockups and complete failures.

    The new nehalem based mac pros have a totally different design for the memory section, incorporating another circuit board alongside the bottom of the case, just above the power supply. I believe that the memory risers were deleted due to this problem.

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