G5 Quad - Cannot Install OS X - Red LED 806

Discussion in 'PowerPC Macs' started by Sepultura, Jul 10, 2013.

  1. Sepultura macrumors regular

    Joined:
    Jul 10, 2013
    #1
    I have a Power Mac G5 Quad. It's the last model they made.

    It has 9GB of ram. 4x2gb and 2x512mb.

    Upon turning on the computer a red LED is on and then turns off. A few seconds later it's back on and stays on.

    Looking into this, it's a ram problem. The led is labelled 'LED806.' It's below the top 4 DIMM slots.

    The computer will turn on, chime, and the screen is black for around 8 seconds before it goes to the gray screen.

    - If I just leave it, it will go to a 'happy mac' folder and stay there. It's a clean hard drive so it wouldn't boot anyway.

    - If I boot the computer hold C with the Leopard disk in, it will go to the gray screen and stay there for sometime until it goes to kernal panic and says 'invalid memory access' etc.

    - If I boot holding option, it will go startup manager but stay there for a long time frozen. Sometimes I can hit refresh and I see the Leopard disk. I try to move forward but it freezes again. Eventually it goes to kernal panic.


    What puzzles me is this ram has always been used with the G5. The 2gb sticks are the same model and so are the 512. The G5 was running strong a few years ago with all this ram.

    So is the ram dead or not? Could it be something else?

    I tried testing the ram. 1 stick at a time and got 2 beeps and the fans went LOUD.

    I tried 2 at the same time in the the same slots 1-1 and it the computer would just do the stuff listed above.

    Thanks
     
  2. eyoungren macrumors P6

    eyoungren

    Joined:
    Aug 31, 2011
    Location:
    Phoenix • 85037
    #2
    It sure sounds like ram. I had a stick go bad about nine months after my boss bought my G5 back in 2005.
     
  3. 666sheep macrumors 68040

    666sheep

    Joined:
    Dec 7, 2009
    Location:
    Poland
    #3
    RAM sometimes fails, you know ;)
    Testing one stick at time in G5 isn't a good idea. It needs matched pairs installed in corresponding slots.
     
  4. Hrududu macrumors 68020

    Hrududu

    Joined:
    Jul 25, 2008
    Location:
    Central US
    #4
    Thats LED 7, which means the CPU is hanging. RAM can cause these problems, but an improperly mounted CPU can too. Also keep in mind RAM MUST be installed in matched pairs, so trying 1 stick at a time will never work in that machine.
     
  5. Sepultura thread starter macrumors regular

    Joined:
    Jul 10, 2013
    #5
    Right I know the order from top down is 4-3-2-1 and 1-2-3-4. I knew it had to be matching but I thought you could do one stick.

    I will try the ram and again report back.

    Sure hope it's not the CPU...
     
  6. rabidz7 macrumors 65816

    rabidz7

    Joined:
    Jun 24, 2012
    Location:
    Ohio
    #6
    If it is the CPU reseating would fix it.
     
  7. Sepultura thread starter macrumors regular

    Joined:
    Jul 10, 2013
    #7
    how am I supposed to reseat the CPU? It's behind the liquid cooler?
     
  8. rabidz7 macrumors 65816

    rabidz7

    Joined:
    Jun 24, 2012
    Location:
    Ohio
    #8
    First try the RAM, and if that doesn't work reseat the CPU.
     
  9. Sepultura thread starter macrumors regular

    Joined:
    Jul 10, 2013
    #9
    I don't think it's the ram. I just tired again.

    2x512mb. Holding option to try to get to startup manager. It goes on with no red light, about a minute after it gets to startup manager red light is on.

    2x2gb. Exact same outcome.

    2x2gb (different set). Same outcome.

    How do I reseat the CPU? It's behind the liquid cooler which looks like removing it could damage the board.
     
  10. rabidz7 macrumors 65816

    rabidz7

    Joined:
    Jun 24, 2012
    Location:
    Ohio
    #10
    http://www.ifixit.com/Guide/Installing+Power+Mac+G5+Processor+and+Cooling+Unit/1953/1
     
  11. Sepultura thread starter macrumors regular

    Joined:
    Jul 10, 2013
    #11
    Ugh this doesn't sound promising...

    I knew this was going to be a hassle. I will have to consider doing this now.
     
  12. 666sheep macrumors 68040

    666sheep

    Joined:
    Dec 7, 2009
    Location:
    Poland
    #12
  13. Andropov macrumors regular

    Andropov

    Joined:
    May 3, 2012
    Location:
    Spain
    #13
    And what's the right tool? I used the one described in Apple's manual, and the pin is broken anyway. But it doesn't matter, the pin isn't necessary for the PowerMac, is just a way to know if it's been opened (for warranty purposes). But I guess yours isn't guaranteed anymore :roll eyes:
     
  14. Sepultura thread starter macrumors regular

    Joined:
    Jul 10, 2013
    #14
    No obviously it's not in warranty anymore. It's long past that.

    I just don't want to break anything, even the littlest of things. The computer inside and out is in great condition.

    I don't see any visible leaks unless it's behind the G5 plating or back behind the logic board.

    This is the last model and I believe they fixed that problem.

    I don't see how that's related to the red LED.
     
  15. Andropov macrumors regular

    Andropov

    Joined:
    May 3, 2012
    Location:
    Spain
    #15
    You won't notice the pin isn't there unless you're looking for it. However, 666sheep says it's easy with the right tools...

    It is related to the red light. The leak kills a CPU card and the G5 can't boot and shows a red light.
     
  16. 666sheep, Jul 12, 2013
    Last edited: Jul 12, 2013

    666sheep macrumors 68040

    666sheep

    Joined:
    Dec 7, 2009
    Location:
    Poland
    #16
    Flat, sharp, thin and non-flexible blade. Exacto knife is too flexible IMO.
    Something like this:
    [​IMG]

    Basically this. CPU doesn't have to be completely damaged yet, and small leak is hard to notice unless you'll remove LCS. Read some more here: http://www.xlr8yourmac.com/systems/G5_CoolantLeak_Repair/G5_CoolantLeak_Repair_p1.html
     
  17. Andropov macrumors regular

    Andropov

    Joined:
    May 3, 2012
    Location:
    Spain
  18. MisterKeeks macrumors 68000

    MisterKeeks

    Joined:
    Nov 15, 2012
    #18
    That's basically what I used.
     
  19. Sepultura thread starter macrumors regular

    Joined:
    Jul 10, 2013
    #19
    My G5 does boot though. I just cannot install OS X and get a kernal panic if I leave it for a while.

    The computer shouldn't even turn on if the CPU is dead?
     
  20. Sepultura thread starter macrumors regular

    Joined:
    Jul 10, 2013
    #20
    I cannot get that pin out I am using a similar blade. All I am doing is chipping plastic off it. It's barely up and I do not want to break it.
     
  21. Sepultura thread starter macrumors regular

    Joined:
    Jul 10, 2013
    #21
    can someone please do a video of this. I have nearly destroyed the top of the rivet and it's still not off. I do not want to break it.

    I looked all over google and I only find dead links to guides.
     
  22. Sepultura thread starter macrumors regular

    Joined:
    Jul 10, 2013
    #22
    OK. I am very impatient when I want to work on something and this forum moves slow at responding so I kept at it.

    I got the rivet out and I think it's ok. I just mangled it really badly.

    I got the side cover off and all I see is a ton of dust.

    Again I don't see how this can be a problem if the computer is booting? I will proceed to the next step regardless.

    Here are some pictures.
    [​IMG]

    [​IMG]

    [​IMG]
     
  23. Sepultura, Jul 12, 2013
    Last edited: Jul 12, 2013

    Sepultura thread starter macrumors regular

    Joined:
    Jul 10, 2013
    #23
    Ok now I am not so sure if it's worth removing this whole liquid cooler seeing how I could damage the CPU pins.

    I really don't see any signs of damage.
     
  24. 666sheep, Jul 12, 2013
    Last edited: Jul 12, 2013

    666sheep macrumors 68040

    666sheep

    Joined:
    Dec 7, 2009
    Location:
    Poland
    #24
    You've confused forum with chat ;)
    Impatience isn't a virtue, especially when you don't know what you're doing.
    Things can only get worse with such attitude.

    Get proper tools, study service manual from link I posted before, google "G5 LCS leak" and you'll discover that you have most prone to leak dual pump Delphi LCS. If leak is small enough to do not damage your computer yet, good for you. But you can't see it through LCS plate, can you?

    Small leak (invisible through plate):
    [​IMG]

    Bigger leak (still invisible through plate):
    [​IMG]

    Big leak (visible through plate - too late :():
    [​IMG]
     
  25. Sepultura thread starter macrumors regular

    Joined:
    Jul 10, 2013
    #25
    Well I don't have either of the tools required to proceed to the next step anyway.

    Looks like they go for $60-80 and have to be long-handled with a magnet... I could put that money towards a new computer.

    I am going to try to borrow one but these look like uncommon tools.
     

Share This Page