mac pro won't start with cover off

Discussion in 'Mac Pro' started by srookard, Jul 21, 2010.

  1. srookard macrumors newbie

    Joined:
    Sep 12, 2006
    #1
    Ok, this one really baffles me. When my Mac Pro is turned off, turning it back on it does nothing but display red LED's internally. When I remove the cover and the internal clear plastic cover - it starts up. This leads me to believe there is some sort of switch which recognizes that the cover has been removed. However, I'm at a loss as to why the boot is failing in the first place. Any thoughts?
     
  2. Roman23 macrumors 6502

    Joined:
    Jun 12, 2010
    #2
    why take the cover off in the 1st place?

    This is strange, as I sometimes start up my machine(diagnostics only) with the cover off.. unless, you have something interferring with it.


     
  3. Cindori macrumors 68040

    Cindori

    Joined:
    Jan 17, 2008
    Location:
    Sweden
    #4
    You do not have a Mac Pro, you have a Powermac.
     
  4. spinnerlys Guest

    spinnerlys

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    Sep 7, 2008
    Location:
    forlod bygningen
    #5
    How do you know that? Clear plastic cover?
     
  5. Mackilroy macrumors 68040

    Mackilroy

    Joined:
    Jun 29, 2006
  6. spinnerlys Guest

    spinnerlys

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    Sep 7, 2008
    Location:
    forlod bygningen
    #7
    So it's a G4 or G5 then? I guess G5, as I vaguely remember some clear plastic inside it, but it is more than five years since I opened one of those G5s.
     
  7. Oldschoolwax macrumors member

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    Feb 5, 2007
    Location:
    NY
  8. CaptainChunk macrumors 68020

    CaptainChunk

    Joined:
    Apr 16, 2008
    Location:
    Phoenix, AZ
    #10
    The clear plastic cover over the internal components is a dead giveaway you have G5. Another way to tell is the presence of only one ODD opening on the front of the case (instead of two, skinnier ones on a Mac Pro).
     
  9. srookard thread starter macrumors newbie

    Joined:
    Sep 12, 2006
    #11
    Ooops

    You're right...my bad. Not to excuse my error, but I was typing it from my macbook pro and had a brain fart.

    Either way....g5 powermac won't start with the cover on. Remove the 'tupperware' lid -- and it starts just fine. (if you want to call having to remove the lid fine)
     
  10. CaptainChunk macrumors 68020

    CaptainChunk

    Joined:
    Apr 16, 2008
    Location:
    Phoenix, AZ
    #12
    Strange. That makes me wonder if there's some sort of safety switch for the clear cover that's buggered and is now doing the reverse of what it should be doing. I sold my G5 over a year ago, otherwise I'd try verifying that for you.
     
  11. halprin macrumors newbie

    Joined:
    Jul 20, 2003
    Location:
    Austin, TX
    #13
    So, are you saying that your Powermac G5 will not boot with or without the cover on? From your topic title, "[Powermac G5] won't start with cover off" it seems that you are saying that it will not boot with the cover off. But, in your original post, you say "When I remove the cover and the internal clear plastic cover - it starts up" making it seem like it will not boot when the cover is in. Which is it?

    Now, if it does not boot with the cover out, that makes sense to me. With the heat this thing makes, it wants to make sure the air is going in and directly out of this thing to cool it.

    And yes, there is a switch there that the Powermac G5 can test to see if the plastic cover is in or not. If you notice, one of the tabs on the bottom of the plastic cover has metal in it. I assume that that the computer does some electrical test and can tell the difference thanks to that piece of metal.
     
  12. tomscott1988 macrumors regular

    tomscott1988

    Joined:
    Apr 14, 2009
    Location:
    UK
    #14
    Answer!

    The powermac g5 had a plastic cover inside for its airflow zones to work, if i remember correctly there are 4 zones, for - HDD, Ram, Graphics and CPU. There is a sensor in-place so it detects the removal of the plastic cover. This plastic cover design was because the powermac G5 processors ran so hot they had to reinvent the air cooling system, the plastic cover in effect seals these zones. Without it the computer will not boot because the sensor detects the zones are not sealed. This was a necessary measure, as the computer is Apples only fully customizable computer people test the machine with new parts etc, the processors ran very hot and therefore could be damaged with the lack of cooling. So Apple didnt want to have to replace G5 machines. So this was the solution. There is also a massive give away it is a G5 because it should have G5 written in big letters over the CPU.


    This video explains the zones at about 2mins 55secs

    http://www.youtube.com/watch?v=tnEbPm8mATQ
     
  13. srookard thread starter macrumors newbie

    Joined:
    Sep 12, 2006
    #15
    Holy crap...errors abound in the original thread. Thats what I get for drinking and posting at the same time.

    :D

    Clear plastic cover in place ---> no boot
    Clear plastic cover off ---> boot
     

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