1 2 3 Previous Next 35 Replies Latest reply: Mar 23, 2014 6:40 PM by BDAqua
apple_customer Level 1 Level 1 (45 points)
Hi, everyone.

My PowerMac G5 dual processor stopped working yesterday. It had been behaving unusually lately with frequent freezes that required it to be turned off and them restarted. I have removed both internal drives and them are both working fine. I also blew some of the dust inside built-up around the electronic boards and the internal fans. In addition I also pressed the reset button to see if it would solve the problem. It still won't start.

As I press the power on button to start the computer I notice that a few seconds later the power on light starts to blink. Not the type of blink that alternates between light on and light off. Instead the light will vary its intensity between low and high. It blinks three times than an short interval follows. Then it blinks three times again followed by an interval. And it continues following this pattern.

Any ideas of what it might be ?

Thank you in advance.

MacBook Pro i7 17", 8 GB RAM, 512 GB SSD, Mac OS X (10.6.4), PowerMac G5 dual 2.0 GHz
  • 1. Re: PowerMac G5 won't start; Power on light blinks.
    old comm guy Level 4 Level 4 (2,230 points)
    That would be a memory problem.

    2 Flashes: No RAM is installed or detected.
    3 Flashes: Incompatible RAM types are installed.
    4 Flashes: No RAM banks passed memory testing.
    5-6 Flashes: Logic board or processor trouble


    Suggest you remove one bank of ram, say the pair in the highest numbered bank, then try to boot.

    If you still get flashing, remove the next lower bank and replace with the pair you took out and try to power the machine again.

    As an aside, you may find that removing and reseating DIMM modules might also help. The frequent freezes are often caused by a memory issue.
  • 2. Re: PowerMac G5 won't start; Power on light blinks.
    apple_customer Level 1 Level 1 (45 points)
    Hi, old comm guy,


    I've tried what your recommended but still nothing changed. My computer has four pairs of ram banks numbered from 1 to 4. I started by removing them all, placing them back to make sure they were seated properly and leaving the original RAM out since it is the oldest one installed (2 x 256 GB that came with the Mac when it was purchased).

    As I started the computer and noticed the same blinking I then removed the pair in banks number 3. Same thing. I then removed the pair in bank 2 leaving only the pair in bank 1. Still the same. I then switched the pair in bank 1 with the RAM that came standard with my computer but the same happened.

    Any ideas of what else might be causing this problem ?

    Thanks.
  • 3. Re: PowerMac G5 won't start; Power on light blinks.
    BDAqua Level 10 Level 10 (116,475 points)
    Try just Bank 2, or Bank 3, or Bank 4 alone...

    4-3-2-1*1-2-3-4

    One other option is heating the RAM slot area with a Hair Dryer for 3-5 minutes to see if that makes contacts inside expand enough to work.
  • 4. Re: PowerMac G5 won't start; Power on light blinks.
    apple_customer Level 1 Level 1 (45 points)
    Hi, BDAqua,

    Thank you for your help and suggestions.

    I've tried all the different memory banks as you suggested but no luck. It seems the problem is not related to the RAM or the memory banks.

    Any ideas as to what else might be causing the problem and how to fix it ?

    Thanks.
  • 5. Re: PowerMac G5 won't start; Power on light blinks.
    BDAqua Level 10 Level 10 (116,475 points)
    Did you try the Hair Dryer yet?

    G5's suffer from the first move into the leadless solder age and sometimes heating the area can make contact.
  • 6. Re: PowerMac G5 won't start; Power on light blinks.
    apple_customer Level 1 Level 1 (45 points)
    Should I use the hair dryer with the RAM installed in the memory banks or do I remove the RAM cards and use the dryer on the banks alone ?

    Thanks.
  • 7. Re: PowerMac G5 won't start; Power on light blinks.
    BDAqua Level 10 Level 10 (116,475 points)
    I've seen both methods, cant testify to which one works more often.
  • 8. Re: PowerMac G5 won't start; Power on light blinks.
    apple_customer Level 1 Level 1 (45 points)
    Hello, BDAqua,


    I just tried the hair dryer technique that you suggested but unfortunately it didn't work.

    Any other ideas as to what might be the cause of the problem and how to fix it ?

    Thanks.
  • 9. Re: PowerMac G5 won't start; Power on light blinks.
    BDAqua Level 10 Level 10 (116,475 points)
    Ate you still getting the blinks on trying to start it?
  • 10. Re: PowerMac G5 won't start; Power on light blinks.
    Matthew Knice Level 1 Level 1 (70 points)
    Hello and welcome to the Apple Discussions! =)

    Well I think its bad RAM sticks, they do go bad after a while. Also, did you ground yourself before reaching into the Mac? Another thing to consider: Try taking a matching pair of RAM cards, a known good pair that work in another machine, and try those. Power Mac G5s require exact matches. Did you have all 8 slots filled? You may have accidentally mixed a few pairs up, or maybe the RAM just went bad? I hope this helps, sorry to hear about such a powerful piece of machinery go down. I love my Dual 1.8GHz Power Mac G5. =)

    Cheers.

    —Matt

    null
  • 11. Re: PowerMac G5 won't start; Power on light blinks.
    BDAqua Level 10 Level 10 (116,475 points)
    Good additional info Matt, thanks for contributing!
  • 12. Re: PowerMac G5 won't start; Power on light blinks.
    apple_customer Level 1 Level 1 (45 points)
    Hi, Matt.

    I've tried what you suggested already. It didn't seem to make any difference. My PowerMac G5 has 4 pairs of memory sticks. One pair of 256 MB each that came installed in my computer, two pairs of 1 GB each and one pair of 2 GB each for a total of 8.5 GB RAM. I have installed them in different order, switched the memory banks and tried one memory bank at a time to eliminate the possibility that the problem was one of the memory banks. Nothing worked and the problem persists.

    Can you and BDAqua think of anything else besides the memory banks and memory sticks that may be causing this problem ?

    Thanks.
  • 13. Re: PowerMac G5 won't start; Power on light blinks.
    BDAqua Level 10 Level 10 (116,475 points)
    I'm afraid it sounds like the RAM Slots or Logic board is pretty bad, only thought I have at the moment is Hair Dryer for a much longer period,

    Doesn't seem ALL the RAM could be bad all at once.
  • 14. Re: PowerMac G5 won't start; Power on light blinks.
    apple_customer Level 1 Level 1 (45 points)
    Hello, BDAqua.

    It seems it is time for my PowerMac to go to computer heaven ...

    This is not a good time for a new computer purchase and this couldn't have happened at more inappropriate time.

    The sad thing is that the computer is in incredible shape. It has been well cared for and looks like a brand new computer. It has always been connected to an external UPS so I know the problem doesn't have anything to do with power fluctuations.

    Well ... Doesn't look like there is anything else I can do.

    Thanks for your help.
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