Power Mac G5 won't turn on

Discussion in 'PowerPC Macs' started by fernandovalente, Mar 1, 2012.

  1. fernandovalente macrumors 6502

    fernandovalente

    Joined:
    Aug 29, 2008
    Location:
    Third world **** hole, I mean, Brazil
    #1
    Hey,

    I got a Power Mac G5 and it won't turn on. I removed that little battery and now when I plug the power cable, the power button flashes, but I'm still not being able to turn it on. It's a 1.8GHz June 2004 model. Does anyone knows how to solve this problem?

    Thanks!
     
  2. troutweed macrumors member

    Joined:
    Aug 3, 2010
    Location:
    Hobart, Australia
    #2
    Try opening up the side, and pressing the little white button at the bottom of the circuit board that the "little battery" was on. It resets something in the power supply. Worked on mine a year or so ago (no longer have it so can't photograph position of button for you.

    Worth a try.

    When mine had same problem, leaving unplugged overnight would usually fix it. Didn't like starting within about 8 hours of a shutdown... ??? Weird.
     
  3. fernandovalente thread starter macrumors 6502

    fernandovalente

    Joined:
    Aug 29, 2008
    Location:
    Third world **** hole, I mean, Brazil
    #3
    I wasn't able to find any white button. Are you talking about the PMU button? If yes, I pressed that a couple times and no luck :(

    After randomly removing the memory, sometimes it turns on, but a red led turns on and the power button keeps flashing twice. If I place the memory again, nothing happens when I press the power button. :(
     
  4. MAC MAN JW macrumors 6502

    MAC MAN JW

    Joined:
    Jul 12, 2011
    Location:
    Buffalo,Ny
    #4
    If it turns on your power supply is probably good:) I think you have Bad Ram or Bad Ram Slots:( I recall seeing a post wear the solder joints on the Ram slots in G5's would come apart and would make the issue your G5 is haveing people got it to work temporarily by heating the Ram slots with a hair dryer:). you may also want to try other Ram in it just in case the RAM has gone Bad.

    (Power button Led diagnostic codes)
    On and solid Computer is on and running
    2 flashes, pause No memory (RAM) is installed
    3 flashes, pause Incompatible memory (RAM) is installed
    4 flashes, pause No good DIMM banks detected
     
  5. chichilocomplot macrumors newbie

    Joined:
    Mar 2, 2014
    #5
    my 2008 mac pro g5 won't turn on

    i need some help here my friends i have a 2008 mac pro g5 and last night was working fine i felt to sleep and this morning when a woke up it was off and i try to turn it up and y won't do anything nothing no even a light please somebody tell me how i fix this problem and thank you
     
  6. AmestrisXServe macrumors 6502

    Joined:
    Feb 6, 2014
    #6
    Please constrain posts to the appropriate forum, and topic. You created a help topic for this, so littering posts that have nothing to do with it, won't provoke sympathy.

    If you have a Mac Pro, please post about it here.

    You will find my response to your inquiry in the thread that you started, and I strongly advise seeking a local professional that does Apple service. Repairing a fault of this nature requires a good wherewithal regarding technical knowledge, pertaining to specific Mac models.
     
  7. thecountmac macrumors newbie

    Joined:
    Oct 25, 2015
    #7
    I noticed my Power Mac G5 dual core 2.7GHz that I use primarily for pro tools had shut itself down overnight. Now it won't power up. No light, clicks or any other signs of life. Tried all the tricks, battery, reset button, etc and nothing worked. I would be simply giving up on the beast and upgrading to a new box, (rather than a costly repair,) however get this, the same machine did the exact same thing about a year ago. I gave up on it then too after trying to similarly fix, but about a month later I was moving my computer station and decided to plug it in, I pushed power and presto, it started right up. It has been running fine without any problem at all, for about a year, that is until this morning when I noticed it had again shut itself down and would not start up.

    I am hoping the information about it starting after a long rest will give someone a idea as to what may be causing this to happen again. Any advise will be greatly appreciated.

    Thanks!
     
  8. DeltaMac macrumors 604

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #8
    Try the old logic board reset.
    unplug everything (don't leave anything attached to the ports on the back for this)
    remove the battery (test it to make sure that it provides at least 3.3 vdc. Get a new battery if the voltage is too low.)
    Don't touch your PowerMac for at least 10 minutes.
    Install the battery.
    Wait 10 seconds, then press and release the PMU reset button. DO NOT press that button a second time.
    Plug in the power cord. Wait an additional 10 seconds, then press and release the power button.
    If the power comes on, you may be OK.
    If not, do you see ANY flashes on the power light above the power button?
     
  9. thecountmac macrumors newbie

    Joined:
    Oct 25, 2015
    #9

    Thank you for your reply.

    I had tried that before, however, just tried it again at your prompt and it did not work. The power button light does not go on at all. No clicks when I plug in adapter. Zero sign of life.
     
  10. MacCubed macrumors 68000

    MacCubed

    Joined:
    Apr 26, 2014
    Location:
    Florida
    #10
    PSU is probably dead, if there was a light then it could be CPU or LB related. Take the processor cover off (G5 panel) and check if the connections are all there.
     
  11. DeltaMac macrumors 604

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #11
    Yep, your power supply has died.
    If you have the service manual for your PowerMac, you can find out how to test the voltage from your power supply. I suspect that you will find that the trickle voltage is zero.
     
  12. thecountmac macrumors newbie

    Joined:
    Oct 25, 2015
    #12
    I suspected that. Just wondering why it did the same thing last year and then after some time had passed, resumed working for almost a year with zero issue.
     
  13. DeltaMac macrumors 604

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #13
    Sometimes your electronics dies a slow death, with occasional symptoms. They don't heal themselves over time, they get worse.
    Your power supply was probably on the edge for some time, and a little extra heat, maybe a minor voltage surge that wouldn't normally affect a good power supply... Who knows, maybe your cooling system has developed a leak (you do check for that occasionally, correct?) The power supply is directly underneath all that plumbing.
    Or, just a capacitor or two inside the power supply decided to crap out.
     

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