Previous 1 2 Next 21 Replies Latest reply: Oct 1, 2011 12:21 PM by Heikki Lindholm
--A--C-- Level 2 (290 points)



I was just surfing the web, suddenly G5 shuts down, as if you would pull the plug.

If I press the power button, it won't reboot. I hear the apple startup chime, and about 5 seconds later, it shuts down again.

Nothing appears on the screen.


I've done this already:

- open the lid, removed some dust

- try to boot with all other hardware disconnected

- try to boot from FW800 lacie external HDD, with a recent clone of my system drive (made with Carbon Copy Cloner)

- take out battery for half hour

no results, still startup chime - then dead.


So I guess:

it should be a hardware error, since it won't boot from the external FW drive.

So it is probably the power supply or the motherboard.


correct? any other suggestions, that I can try before taking it to Apple repair service?

( I had a dead powersupply in 2007 in the same machine, costed me +300 euro)


Any help is appreciated.

Regards, A.C.

 G5 PPC dual 2GHz (june 2004 model) / 3.5GB RAM, Mac OS X (10.4.11)
  • --A--C-- Level 2 (290 points)

    Safe Boot from the HD, (holding Shift key down at bootup) doesn't work either

    don't know what else I could try.

  • BDAqua Level 10 (121,620 points)

    Does it boot for a longer time if cooled off?


    Did you blow the dust out of the PSU & graphic card?

  • --A--C-- Level 2 (290 points)

    Hi BDAqua, thanks for your response.

    That was also the first thing on my mind: shutdown because overheating, but no.

    I've let the machine cool down for almost an hour, and the problem is still the same.

    For your information: I did not notice any extra fan noise prior to the shutdown.


    Right now I don't have a can with compressed-air available, so I did it with a big bycicle pump haha.

    My father has an air compressor, I'll take the machine over there later this week, to blow the dust out properly.

    But I do not have a lot of hope that this will change anything.


    As for the PSU: as far as I understand, in this G5 models, it is all the way in the bottom, quite hard to reach, have to take everything out, that's why it's a rather expensive replacement. So not sure if the compressor will be able to blow all dust away in there??

  • BDAqua Level 10 (121,620 points)

    Yes, the PSU is hard to reach, but a good Air Compressor might be able to blow some out... btw, I wouldn't waste my money on Canned Air.

  • --A--C-- Level 2 (290 points)

    I agree with you on that: there are not much things more overpriced than canned air. unbelievable what price some computer shops dare to ask for that :-)

    Anyway, my father is on vacation, he will not be back before sunday, so I'll wait patiently to try this last option.

    In the meanwhile, I'll take out the HDD's and pop em into a friend's G5, and do another CCC clone to rescue the data from the last two weeks.


    Something else I was thinking: What are the symptoms if the little battery is no longer good?

    Could it cause a shutdown like in my case?

    I think I also replaced it in 2007 but I'm not sure.


    If it is indeed the PSU or the motherboard, I think it's unwise to invest in this machine any longer.

    I'll save the money then to buy a minimac later on. Fresh machine, lion, good for many years to come.

    Also the power consumption of the G5 is quite a big deal, 300Watts I believe.

    Maybe I can still sell the G5 for spare parts? maybe the RAM is still worth something?

  • Limnos Level 8 (46,035 points)
    Something else I was thinking: What are the symptoms if the little battery is no longer good?

    Unlikely to be the problem unless it is dripping acid or something. Bad batteries usually mean startup problems, not running problems.  Lifespan depends on how much you disconnect your computer from mains supply.  I've had them last 5+ years because I always leave mine plugged in.


    Also the power consumption of the G5 is quite a big deal, 300Watts I believe.

    Laudable in some ways but "green" is not always simple. How much resources to make a new computer? Somebody once said if you want to buy a green house buy an old one that is already build and doesn't use more resources to construct new.  Then too figure out the actual cost savings of a newer computer vs. older. At, what, 10c a kilowatthour I think it would have to be left running a long time.


    Maybe I can still sell the G5 for spare parts? maybe the RAM is still worth something?

    Could probably get more money parting it out but it's up to you if you want to spend the time unless you already do a lot of e-bay, Craigslist, Lowendmac selling.  I look at something and figure I might get $20 for it, but then I think it will take me an hour to package it, go to the post office, have to buy packaging, etc, and figure it is marginal.

  • --A--C-- Level 2 (290 points)

    Battery is not leaking, looks fine. My G5 is also always plugged in. So that won't be the problem either.

    thanks for the reply.


    about the power consumption: my G5 is on many hours a day, so I think that ads up. Don't know about energy prices in USA, but in Belgium it's rather expensive and increasing rapidly.

    Furthermore. When it is the PSU, and I replace it, it's still an old machine, what's going to fail next? My CPU's, my motherboard?

    I am still considering to replace it, but then I would have to find one for a decent price, and do it myself. I'm not going to pay another 300/400 euro to apples repair service.


    You're probably right about selling the parts. won't do that.


    Today I cloned the HDD's, with another G5. there was nothing wrong with them, so it is definitely a hardware problem.

  • --A--C-- Level 2 (290 points)

    Hmm... after a bit of reading on the internet, I found out that a lot of G5's suffered from dead PSU's in the past.

    As I mentioned earlier , I had a broken one in 2007, and now probably again.

    I'm a bit angry that the Apple Premium Store were I did the first repair, did not mention anything about the extension warranty program:

    It was apparently a well known issue, and they still let me pay for it.

    Too late now, the extention warranty is closed since 2010.


    Anybody got an idea were I can still order a PSU, and price?

    and a manual how to replace it?

  • --A--C-- Level 2 (290 points)

    Thanks a lot BDAqua!

    I'll look into that asap.

    For anyone interested, I also found these take-apart manuals:

  • --A--C-- Level 2 (290 points)

    Okay, I finally got my G5 to my fathers house, and blew it out completely with his powerful compressor.

    Put it on 5 bar pressure (72PSI), the cloud of dust coming out of the PSU region was unbelievable.

    Just plugged my G5 in, got beyond the 5 seconds, and yes, booting again ! The air compressor did the trick. I am a happy man today :-)

    thanks again BDAqua and others for your help and suggestions.


    For anyone else with similar problems, you might want to take a look at this thread too:

    particularly this pictures of dust gathering in G5 PSU are mindblowing:



    "Blow it out now, before it blows itself out later" (quote : old comm guy)


  • BDAqua Level 10 (121,620 points)

    Great news, thanks, good work!

  • old comm guy Level 4 (2,240 points)

    My two cents worth to add here is simply that this issue is continuous. 


    I installed the replacement supply about 15 months ago in the G5.  Last month, as a part of shoving some more RAM into the G5, I took the opportunity to drag the carcass out to the garage and give everything, including the power supply region, a good shot of dry air at the OSHA nozzle pressure and got a nice little dust cloud, though nothing like what I got out of the original supply when I blew it out. 

    This little effort has now translated into a for-sure annual maintenance routine.  Living in a very temperate climate, we have house windows open most of the time (keeps wife of OCG happy) which unfortunately admits a lot of dust kicked up by breezes and the busy street behind us.

  • --A--C-- Level 2 (290 points)



    happiness didn't last very long.

    My G5 has worked well again for just one day.

    After running well 8 hours or so, I had a freeze, couldn't do anything, besides pushing the button for 5 seconds to power off, and reboot again. Four hours later it fell out again, while I was doing something else. First thought it had fallen asleep, but then I didn't see the "breathing" light. Tried to boot again, same problem as explained in my first post: startup chime, automatic shut down after 5 sec.




    First of all, I forgot to mention that I did not take apart the G5 to take out the PSU. I just blew it out through the grid, on both sides a few times, until I saw no more dust coming out.

    So, when the G5 died again yesterday night, I figured, maybe there was some dust left in the PSU, in some place hard to reach while blowing through the grid? Maybe the fans spinned the whole day blowing the remaining dust back where it was before?

    So I just spent my evening, carefully disassembling the whole thing, expecting to find more dust.

    It wasn't easy at all, starting with the plastic pin holding the CPU cover, which was a real pain in the *** to remove. Some cursing occured. The "cup hook trick" worked in the end, although it wasn't easy. The plastic plug is fubar, but I understand it's not really necessary to put it back.

    Also the Allen screws holding the CPU's where quite hard to reach (you need a 15cm T10 torx).

    Anyway, got the job done, and was surprised when I opened the lid of the power supply.

    No dust in there !?! Hmmm.... there goes my little theory!

    Now everything is taken apart, I will blow it out one more time tomorrow at work (don't have a air compressor here at home), but I must say, I don't have a lot of hope left.


    If anyone here has reasons to believe it might not be the PSU, please let me know what else it could be, or what I can try.


    Oh, one more thing: when I mailed the nearest Apple Repair service centre, (Switch Shop, Gent, Belgium) they replied: "Dear Customer, For these devices Apple provides no more parts. Therefore, your model can no longer be repaired." They didn't even answer my question, if they could measure out and determine if it really is the PSU that is the culprit.

    Great. Mac Pro (2770 euro): no more apple support after 7 years, maybe less. Failure? too bad, sort it out yourself. - Or even better: buy a new mac!

    Yeah right. I will eventually, but only because I hate windows, and I like the elegance of the Mac OS.

    Anyway I found out that buying a second-hand G5 locally, is probably cheaper than a refurb / new PSU + shipping costs. On the other hand: how long will that one last.

    Doubts, doubts. headache.


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