How hard is it to replace your Power Supply Unit?

Discussion in 'PowerPC Macs' started by PupnTaco, Jan 8, 2008.

  1. macrumors regular


    May 29, 2007
    As noted in a previous thread, I have a dying Power Mac G5 (dual 2 GHz). I'm wondering about the wisdom of trying to replace the power supply myself, if indeed that is the cause of my problems. The computer has been crashing a dozen times daily and cannot be rebooted unless you open the case & push the PMU reset button.... so I'm making an uneducated guess that it's the power supply that either needs cleaning or is getting ready to fail.

    I see at this site (DT&T Service) they're selling replacement power supplies for $145.... and I found detailed instructions on how to disassemble the G5 here.

    So, I could:
    A) take the G5 to Apple and have them fix it for $1700 minimum
    B) buy a new Mac Pro for $4800
    C) roll the dice and spend $145 to see if I can fix it myself with the help of a friend who's handy with Apple hardware.

    Worst-case scenario: I annihilate the G5, which feels like its on its way to dying anyway. Best-case: I can keep working without spending the money I don't have right now.

    What would you do?
  2. macrumors 6502a


    May 6, 2006
    Leeds, UK
    Personally I'd try giving the power supply a good going over with a can of compressed air first. Get all the dust out of there that might be causing it to over heat.
  3. macrumors member

    Dec 29, 2007
    The G5 power supplies are a pain to replace. Since they're on the bottom of the machine EVERYTHING has to come out. Processors, logic board, yada yada. I've replaced the logic board, processors, power supply on a G5 once and I definately would not do it without having acces to the service manual.
  4. thread starter macrumors regular


    May 29, 2007
    Found one through diligent Googling and reposted the 11-page, 6MB PDF here for anyone else who needs it.
  5. thread starter macrumors regular


    May 29, 2007
    As a follow-up, I didn't need to replace the power supply - just had to disassemble the case for it and remove all the clumps of dust that were blocking airflow through the unit.

    Thanks to the service manual, I was able to do it pretty easily by myself and have resolved my kernel panic problem.
  6. macrumors 6502a

    Aug 7, 2007
    I have a question about compressed air actually lol.

    I brought some and used it on a laptop and it actually looks like it makes it wet and crackles, is it suppose to do that??? :confused::eek:
  7. macrumors 68000


    Oct 20, 2007
    It does if you dont hold the can upright.
  8. macrumors 6502a

    Aug 7, 2007
    Oh right and I take it 1) you should hold it upright and 2) can that damage your comp?
  9. macrumors newbie

    Dec 15, 2008
    DIY manual

    I am in the middle of no where so shipping my Power PC to repair and back again is not cost effective.

    I am 99% power supply died (machine doesn't come on anymore.. nada)

    so I would like to replace PSU... I have played with powerbooks before so I am not uncomortable but would like to find some guides as to how to get the processors out

    I have a G5 2.0 dual processor as I understand its a rev a since the processor cover is two pieces..

    any ideas would be greatly appreciated

  10. macrumors 601


    Sep 16, 2007
    Northeastern Ohio

    Run your serial number in the Apple site to see if you fall under their PSU extension program.

    I have the Powermac G5 service manual. It's too large to upload it on here and I can't remember where I downloaded it but if you want it, I can email it to you. It's 6.5mb.
  11. macrumors newbie


    Apr 13, 2009
    service manual

    hey OrangeSVTguy

    can you e-mail me a copy of the service manual? i have not been able to locate a copy online yet, i would appreciate your assistance.(

  12. macrumors newbie


    Oct 11, 2008
    Los Gatos, CA
    Hey OrangeSVT guy or spinman08, could you hit me up with a copy of that manual, too? My power supply here at work just kicked the bucket, too, I believe . . . my e-mail is kevielumps at

  13. macrumors 68030


    Dec 26, 2002
    Albuquerque, NM
    Duff-Man says....even if your s/n is not within the ones listed by Apple I would still call them as they may replace it free of charge anyway - they did with mine without much prodding at all and mine was about a year out of the range of machines supposedly affected....oh yeah!
  14. macrumors regular


    Mar 17, 2009
    How about PSU of mac pro 09' any guide how can i change it?
  15. macrumors 6502

    Feb 13, 2009
    If you computer is on I am pretty sure that will kill it. If it was off I'm not sure. It evaporates in a second, but I don't know if there is residue left behind. I'm also not sure if it is conductive. Also, it being a laptop (or anything with capacitors) it is always possible to short circuit it even when it is off if you get it in the wrong place. Gotta love capacitors. Never touch a power-supply's internals even if it is unplugged. Thats what all those warning stickers saying "Do not open. Shock hazard. Service technicians only." are about.
  16. macrumors newbie

    Apr 23, 2009
    Pass along a copy?

    Just had a PowerMac G5 psu fail here at work.

    Can somebody pass along that guide to bryanlaraway at gmail?

  17. macrumors member


    Nov 29, 2008
    my g5 dual 2.3ghz early 2005 modal failed to start because of the psu somehow boom. took it out the psu(not easy if you do not have the long handled torx screwdriver - T10 at least 150mm long) , remove the both processor then remove the cover on top of the psu then voila, its out. throw away the huge psu pcb board dump in the normal 500w ATX psu, rewiring and re-pin the 24pin connectors and now my g5 is running fine.
  18. macrumors newbie

    Dec 13, 2004
    Hi there,

    my dual G5 powermac psu has died on me also, i would very much appreciate if you could forward that guide to me:

  19. macrumors 65816


    Sep 23, 2005
    below Ash Tree Lane
    Just a suggestion: put
    rogerson1987 AT hotmail DOT co DOT UK
    in the future, saves you from spammers or something (?).
  20. macrumors 68020


    May 21, 2009
    Munich, Germany
    For users in Europe I recommend Golytronic in Germany for PSU repairs. They are very experienced and quickly found out that mine was actually ok. In my case it turned out one CPU had died.

    Lucky for me it was a 1,8 GHz and those can boot on one CPU if you remove the defective one. Anything higher than 1,8 GHz and you cannot use this simple diagnostic trick.
  21. macrumors newbie

    Sep 21, 2009
    G5 service manual

    My power supply is dead, too. Can you e-mail me the service manual? Thanks!

    SOLUTIONS atsymbol MCCLUNGCO period COM
  22. macrumors member

    Jan 5, 2002
    Actually, only the CPU assembly should need to come out, but reseating that thing properly is a pain. I wouldn't recommend it for the faint of heart, but it's certainly doable.
  23. macrumors 601


    Sep 16, 2007
    Northeastern Ohio
    Hey everyone, if you still need that G5 Service manual, I have it. Sorry I never replied back to anyone.

    So if you need it, just hit me up.

    For the following models:

    Attached Files:

  24. macrumors 65816


    Dec 7, 2008
    The hub of stupidity
    With limited knowledge, one could easily damage the liquid cooling inside of the G5 during an intensive repair like that if they weren't careful. If I were you, I would go to the Apple Store and ask for a quote to have it replaced, but I suspect that buying a new machine would be the better option. What you do with your money is your option, but it seems that just shelling out for the new Mac Pro now will make better financial sense than pumping money into a dying machine.
  25. macrumors 601


    Sep 16, 2007
    Northeastern Ohio
    Only the 2.5 and 2.7 models were liquid-cooled and besides the OP is over 1-1/2 years old :p. I think they moved on by now ;)

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