Powermac G5 start up issues

Discussion in 'PowerPC Macs' started by Davince, Feb 11, 2015.

  1. Davince macrumors newbie

    Joined:
    Feb 11, 2015
    #1
    Hi all,

    I used to be 'exclusively' mac in the time before powermac's, so when a friend asked me if I wanted a G5 they had sat in the garage I thought why not!

    First time I got it home, I plugged in an old dell keyboard and mouse and a monitor... fired up instantly. Ran for about an hour while I fiddled around to have a look at it, shut down fine.

    Next day, it booted, then after a few seconds, powered down. Once it was powered down the white LED on the front remained lit, pressing the button did nothing. Since then, I try from time to time, it'll power up, sometimes go all the way through boot, sometimes fail at boot, sometimes chime, sometimes run for 20 minutes, but eventually it always just powers itself off instantly, and then the white LED stays lit until you unplug it from the mains and leave it about half hour.

    Any ideas? (other than throw it in the bin :p )
     
  2. eyoungren macrumors P6

    eyoungren

    Joined:
    Aug 31, 2011
    Location:
    Phoenix • 85037
    #2
    Try reseating the ram and the video card. In the case of the video card, re-insert it firmly, but not hard enough to cause damage.

    Is there any dust inside the Mac? If there is you might also want to blow that out as well.
     
  3. Davince thread starter macrumors newbie

    Joined:
    Feb 11, 2015
    #3
    well blow me... brushed against the graphics card and the white light went out instantly, wobbled it a bit and tried to power up - straight fire up. clearly a dodgy contact, it's a bit grimy in there so will clean it up and reseat it again and see how we go!

    You're a star, cheers :D
     
  4. eyoungren macrumors P6

    eyoungren

    Joined:
    Aug 31, 2011
    Location:
    Phoenix • 85037
    #4
    Cool! Glad it worked!
     
  5. bunnspecial macrumors 603

    bunnspecial

    Joined:
    May 3, 2014
    Location:
    Kentucky
    #5
    Glad that it's working for now.

    If it's a Dual 2.5ghz, Dual 2.7ghz, or Quad 2.5ghz model, you might want to take a very close look at the cooling system on the CPUs. These are all liquid cooled, and leaks are not unheard of(although supposedly the Quad is a lot more reliable than the other two). A leaking cooling system can ruin your day VERY fast.

    All other G5 models are air cooled, and don't have this potential failure point.
     
  6. Davince thread starter macrumors newbie

    Joined:
    Feb 11, 2015
    #6
    in that case it's not one of those I don't think - lots of fans and no sign of liquid lol. Once I've powered it up properly, I will take a poke and see what it actually is. Seems the graphics card seating is very dodgy, only have to knock the mac and it won't work again, wobble the board, off it goes (solder joint maybe?)

    ----------

    hmmmm now getting a long tone before the chime, and it boots to a white screen with welcome to open firmware and asks me to type mac-boot?
     
  7. bunnspecial macrumors 603

    bunnspecial

    Joined:
    May 3, 2014
    Location:
    Kentucky
    #7
    What happens when you type mac-boot? It should boot normally into OS X from there.

    In any case, you might try a PRAM reset. Hold down Command(or the Windows key)+Option(alt)+P+R and then hit the power button. You should here the start-up chime, and then several seconds later hear the startup chime again. You can then release the keys, and the computer should boot normally.
     
  8. eyoungren macrumors P6

    eyoungren

    Joined:
    Aug 31, 2011
    Location:
    Phoenix • 85037
    #8
    Your video card could be bad. Worst case would be a CPU or logicboard starting to fail.

    Is the video card screwed down to the frame, or is is just loose?

    I suppose if someone were particularly malevolent they could have worked the card so that the AGP socket itself was starting to come loose from the logicboard, but that would be extreme I think.

    The white screen you are experiencing is Open Firmware.

    Try this the next time it comes up…

    Type:
    reset-nvram (RETURN)
    reset-all (RETURN)

    This will reset PRAM. You can also do the same by holding down CMD+OPTN+P+R when rebooting. If you do that, keep holding the keys until the Mac has chimed at least twice after the first chime.

    ----------

    The long tone might be RAM. Try reseating your ram as well. G5's use ram in pairs so make sure that you reseat it in the same place you find it.
     
  9. Davince thread starter macrumors newbie

    Joined:
    Feb 11, 2015
    #9
    cheers, typing mac-boot it does indeed boot up into os properly - but if you shut it down the power button is iffy still, you have to wobble the GC and then it pops up. I'll strip it down and clean it properly and also follow the above suggestions! Seems to run fine once it's actually running, just getting it there isn't so straight forward.
     
  10. Gamer9430 macrumors 68020

    Gamer9430

    Joined:
    Apr 22, 2014
    Location:
    Central New Jersey, USA
    #10
    Try pressing the PMU reset button, located under the bottom RAM. My power light got stuck on and I pressed the button and it worked fine, might just need a reset. But also clean it out, just to be safe
     
  11. Davince thread starter macrumors newbie

    Joined:
    Feb 11, 2015
    #11
    Tried the PMU button before I posted without success, thought it would be too easy :D
     

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