Quad G5 not booting

Discussion in 'PowerPC Macs' started by Redsand187, Dec 16, 2010.

  1. macrumors member

    Joined:
    Jan 4, 2008
    Location:
    Central Washington State
    #1
    2.5 quad G5 will not boot. It will either boot to the gray screen, with the apple logo and the turning timer, or sometimes it will just go straight to a blue screen. This computer started fine, except it had infrequent kernel panics, 6 months ago when put in storage. Now when pulled out and attempted to use again this is happening. I was told that a bad processor may be the cause of the kernel panics. However, the machine never refused to boot when in operation before storage.

    Also it looks as if LED #2 and #7 are lit up.

    I'm kind of at a loss. It will not boot from the install disk or in in safe-mode. The PRAM has been reset, as has the PMU. No visible signs of coolant leaks.

    Any tips, or ideas would be greatly appreciated at this point. :(
     
  2. macrumors 6502a

    VanneDC

    Joined:
    Jun 5, 2010
    Location:
    Dubai, UAE
    #2
    unplug asap...

    remove the cpu cover (search for how to) and inspect for leakage/corrosion.....

    dont re-plug it it as it could be hazzadous to your health if the psu is getting slightly damp.

    if you cant do that yourself, take it to someone who can... dont stuff around with mains power, you can get a freakingly nasty shock..
     
  3. macrumors 601

    OrangeSVTguy

    Joined:
    Sep 16, 2007
    Location:
    Northeastern Ohio
    #3
    Click on the Apple in the left hand side and click about this Mac. How many processors does it say?
     
  4. macrumors demi-god

    Nugget

    Joined:
    Nov 24, 2002
    Location:
    Houston Texas USA
    #4
    That's sort of hard to do on a machine that won't boot.
     
  5. 666sheep, Dec 20, 2010
    Last edited: Dec 20, 2010

    macrumors 68040

    666sheep

    Joined:
    Dec 7, 2009
    Location:
    Poland
    #5
    See attachment. Remove all RAM except 2 sticks (test few pairs to be sure). If it won't help, it seems that CPU (or both) is gone...
    It could be caused by leak. You may not see it if it's small. Remove CPUs and check pump(s), gaskets and all connections of hoses.
    If you need service manual for your G5, PM me your email adress.
     

    Attached Files:

  6. thread starter macrumors member

    Joined:
    Jan 4, 2008
    Location:
    Central Washington State
    #6
    Okay, I started fooling around with the machine again today. I doubt it's likely, but could a bad battery cause issues like this? I have checked everything out there is no signs of leaks anywhere.

    My main issue is how do I know if it's the processors or the logic board? I wouldn't mind possibly doing one or the other, but not both. If I can source affordable used parts, that is.
     
  7. macrumors 68000

    Joined:
    Feb 13, 2009
    Location:
    United Kingdom
    #7
    You could try getting the Apple Hardware Test for your model (May be on your install disks) if you can get the machine to powerup at all, or you could try replacing components (Although this can cause fan havoc if you dont have the Thermal Calibration Disc) - other than that Im not sure how you can see which it is.
     
  8. macrumors 68040

    666sheep

    Joined:
    Dec 7, 2009
    Location:
    Poland
    #8
    Did you remove CPUs cover and CPUs with LCS? Big leak can be noticed without removing them but you won't see small one this way.
     
  9. macrumors 601

    OrangeSVTguy

    Joined:
    Sep 16, 2007
    Location:
    Northeastern Ohio
    #9
    Yeah good point. I kinda misread the OP :eek:

    Do you have the tools to remove the processor/LCS assembly? There could be a small leak where the CPU meets the heatsink as there is a rubber gasket that sometimes causes slow leaks. This can short out the CPU.

    A bad CPU or LCS pump could be the cause. The water blocks can also be clogged reducing the water flow and causing the CPUs to overheat.
     

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