Powermac G5 - LED blinks 3 times
  • Priest of the Order of the Butterfly
    Priest of the Order of the Butterfly
    analogkid
    Posts: 588 from 2004/11/3
    From: near myself
    Hello,

    I've tried to fix my old G5 (DP 2 GHz PCI-X)

    https://everymac.com/systems/apple/powermac_g5/specs/powermac_g5_2.0_dp.html

    It was on my attic for some years now, and recently I tried to make it work again. The PSU was broken, so I swapped it with one from another broken G5, and now I've got the problem, that it still doesn't start. The PowerLED blinks 3 times, and the posts on the internet say that this is a RAM issue. Well, I swapped various RAM sticks in the correct order, took different RAM of the same type. But the error still occurs. Is there the possibility that some other things are broken? I resetted the SMC (or PMU), too. No change.
  • »11.10.20 - 18:28
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  • Butterfly
    Butterfly
    Posts: 69 from 2017/8/6
    Just to be sure, you placed the RAM sticks really in the correct way, as described in the manual, not the way one would think it has to be done?
  • »11.10.20 - 18:33
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  • Priest of the Order of the Butterfly
    Priest of the Order of the Butterfly
    analogkid
    Posts: 588 from 2004/11/3
    From: near myself
    The correct way is:

    4
    3
    2
    1

    1
    2
    3
    4

    Right? This is the way I put them back.
  • »11.10.20 - 18:35
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  • Paladin of the Pegasos
    Paladin of the Pegasos
    koszer
    Posts: 1033 from 2004/2/8
    From: Poland
    Memory controller, perhaps?
  • »11.10.20 - 18:39
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  • Butterfly
    Butterfly
    Posts: 69 from 2017/8/6
    @analogkit
    yes.
  • »11.10.20 - 18:44
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  • Priest of the Order of the Butterfly
    Priest of the Order of the Butterfly
    analogkid
    Posts: 588 from 2004/11/3
    From: near myself
    Quote:

    koszer wrote:
    Memory controller, perhaps?


    Hmm, is there a way to find out more details?
  • »11.10.20 - 18:47
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  • ghh
  • Just looking around
    ghh
    Posts: 13 from 2017/7/16
    From: Prague
    I had the same thing on the G5 1.8 single cpu. I tried to change the memory sticks, but in the end the memory slots or the memory controller were bad. (I don't know exactly)
    I found the most probable reason on the Internet - microcracks in the soldering of those slots. Also instructions on how to fix it with hot air, or baking in the oven. !! # @
    I was already so desperate that I bought a hair dryer (I'm bald) and heated the board in the place where the memory slots are for about 10 minutes.
    G5 really started working, but only for a week and then G5 boot only randomly and I finally bought another G5.
    Theoretically, it could be fixed, but I don't have the right tools.
  • »11.10.20 - 20:06
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  • Paladin of the Pegasos
    Paladin of the Pegasos
    koszer
    Posts: 1033 from 2004/2/8
    From: Poland
    Quote:

    analogkid wrote:
    Quote:

    koszer wrote:
    Memory controller, perhaps?


    Hmm, is there a way to find out more details?


    You've got 8 memory slots. Try putting a pair of RAM sticks that are surely good in just one pair of slots (1-1, 2-2, 3-3, 4-4). If that doesn't help I think we can rule out the bad solder joints on memory slots. That would suggest it's the memory controller fault. Sadly, it's located on the other side of the motherboard. If you did change the thermal paste and refurbished id properly then maybe - as a last resort solution - you could treat it with some hot air and see if this helps?
  • »11.10.20 - 20:54
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  • Priest of the Order of the Butterfly
    Priest of the Order of the Butterfly
    analogkid
    Posts: 588 from 2004/11/3
    From: near myself
    Quote:

    koszer wrote:
    Quote:

    analogkid wrote:
    Quote:

    koszer wrote:
    Memory controller, perhaps?


    Hmm, is there a way to find out more details?


    You've got 8 memory slots. Try putting a pair of RAM sticks that are surely good in just one pair of slots (1-1, 2-2, 3-3, 4-4). If that doesn't help I think we can rule out the bad solder joints on memory slots. That would suggest it's the memory controller fault. Sadly, it's located on the other side of the motherboard. If you did change the thermal paste and refurbished id properly then maybe - as a last resort solution - you could treat it with some hot air and see if this helps?


    Thanks for that suggestion. I tried putting a pair of sticks in the two according RAM slots, but this didn't help. I'll disassemble the machine and look closer at the memory controller.
  • »11.10.20 - 22:11
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