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PMG4 QS is dead! Help!!!

Discussion in 'PowerPC Macs' started by iLoveiMacs, Jul 16, 2010.

  1. macrumors member


    I bought a Power Mac G4 Quick Silver (used) last April. It worked for about a month before it crapped out. The Specs are:

    Dual 1.0 GHz PowerPC G4
    1GB RAM
    250GB HDD

    When I boot it up by pressing the power button on the front of the computer, the light on the button turns on and i hear the fans start up for literally a second, and then it stops. I believe this might be the power supply. I would love to get this :apple: fixed! I would appreciate it if anyone could help me troubleshoot or better yet, help me find a power supply for the PM? I don't care how much it costs. Thanks for your help!
  2. macrumors member

  3. macrumors newbie

    Sounds like a Logic Board to me
  4. macrumors 68000


    dead logic boards don't spin fans or light leds...

    i would disagree. the first thing i'd check is the PRAM Battery as i've seen it cause this exact symptom. pull the old one and check it with a multimeter, or take it into a store to have it checked, or just replace it because they all need replaced at this point...

    second would be the power supply. possible to rig a cheap/standard ATX supply, but for the non-modder, i'd stick with an actual OEM replacement. best of luck.
  5. macrumors 68040


  6. macrumors 68000


    i disagree, as i've worked on lots of systems with the same symptom and were all related to a dead PRAM battery.

    i agree that the machine will normally start and run just fine without the battery, as i have a pismo that i uplugged the battery in years ago and it works just fine.

    the thing is, that when the battery goes dead, if PRAM/CUDA get corrupted, the machine will no longer turn on, and the battery has no power to reset CUDA when the button is pushed (ONLY ONCE!)

    i'll stick with - replace PRAM battery, reset CUDA (yes, i know it's for a different machine, it works the same for all) and then hopefully boot and reset PRAM. best of luck.
  7. macrumors 68040


    I've never had such an issue caused by dead battery (about 100 QS and MDDs passed through my hands) but cannot negate that you had ;)
    Let's see what'll be OP's experience in this case.
  8. macrumors member


    Thanks for the replies! I'm on vacation right now but I'll try all of your suggestions tomorrow and see what I come up with. I'll be sure to let you all know!
  9. macrumors 68000


    you might be right, i might be crazy.

    i agree. nothing against your post/recommendations, just have seen lots of systems over lots of years, and if i'm wrong, so be it. it won't be the first time...

    hope you can get it fixed. the QS is still one of my favorite systems of all time. crazy/awesome/beautiful case! best of luck.
  10. macrumors member



    I came home today and tried the CUDA switch, but it didn't work. I'm convinced that the Power Mac needs a power supply. Can anyone recommend power supplies/places to get them through this thread or by PM? Possibly links? I don't even know what to "Google" or search on eBay. :confused:
  11. macrumors 68040


    If you're sure it's PSU, you need this: http://www.welovemacs.com/6612513r1.html - but price...:eek:
    Did you test PSU like I've suggested? It's easy: you need a little thick wire, short out PW OK pin (green wire) with GND (black wire) then connect power cord to PSU. Connect HDD to one of molex plugs, to give PSU some load. If it will start this way - it's OK.
    If not - search eBay for proper PSU. If you are not using ADC connector on your graphics card, you can mod ATX PSU to work in your QS. Use pinouts from site I linked. This will be helpful too: http://atxg4.com/quicksilver.html

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