PowerMac G5 freezing?

Discussion in 'PowerPC Macs' started by StUPoT, Dec 18, 2012.

  1. StUPoT macrumors member

    May 23, 2011
    Hi I recently acquired G5 for free from a listing on gumtree cos of a house clearance and thought 'hey it's old but why not'.

    Anyways, I got it home and turned it on and the flashing folder appeared. So fair enough i put my Leopard disc in the drive and it fires up into the install menu. No probs there...

    As it starts to install however, its freezes... No mouse activity or keyboard.. nothing! Then the fans start their impression of a jet engine!

    After a few more goes and the same thing happening I thought I would investigate inside. Nothing wrong there either. No water spill as this one luckily isn't water cooled and everything looked fine.

    So I jumped on the web and found some things to do like the lil button on the logic board and heating ram slots with a hairdryer and removing the bottom CPU etc etc but it still does the same, and sometimes it chooses not to boot aswell.

    I checked the power supply and no probs either.

    So Im guess what im asking is... The LogicBoard nackered? As I have no more ideas of things to do

    Thanks for any help
  2. Zotaccian, Dec 18, 2012
    Last edited: Dec 18, 2012

    Zotaccian macrumors 6502a


    Apr 25, 2012
    First of all perform PRAM and SMC resets, just in case and then try installation.

    It however sounds like motherboard failure. Very common on PowerMac G5's. The problem is usually the chipset/memory controller being disconnected because of a solder failure which occurs after repeated heating and cooling cycles. I think this is the case here. The chipset on these machines run insanely hot during use, if I recall right temperatures were like 70-80 celcius, never seen this kind of temperatures with any PC that I have owned, maybe half of even less of those temps.

    What you can also try is to test with known good memory to rule it out, if you have original install disks they have Apple Hardware Test which can be used, but the thing is that in this motherboard failure case it might say that no problems even though there clearly is when operating system cannot be installed or booted.

    If it is the motherboard failure, the fix would be to either replace the motherboard or perform reflow/reball of chipset.
  3. StUPoT thread starter macrumors member

    May 23, 2011
    Is the memory controller on the underside of the logic board under a heatsink?
    Do you think cooking it in an oven would sort it? I have done this with a few MacBook Pros and they have always worked afterwards.
    I havn't got anything to loose really as it appears the board is bust anyway.

Share This Page