Power Mac G5 No Chime Loud Fans on boot

Discussion in 'PowerPC Macs' started by c3rberu5, Sep 2, 2013.

  1. c3rberu5 macrumors newbie

    Sep 2, 2013
    Hi All,

    I just picked up a 2x 2.0 Power Mac with the issues in the title, was a cheap pickup so why not.

    Before I booted the machine I removed the battery and reset.

    I then power on:

    - Mac chimes
    - There is display on monitor, although the picture is garbled. I put this down to a possible heat issue as it looks like the artifacting from overclocking gpu's
    - Remove card - Replace thermal paste and thermal pads, reassemble card heatsinks, fan etc. I've done this a good number of times, with many different cards without issues so there is only slim chance of me having damaged the card.

    I then replace the card (Geforce 6800 Ultra)

    - No chime
    - No display
    - Loud fans
    - Rear optical light is lit continuously

    I've ruled out the following:

    - Ram is fine - Did not move it since initial boot
    - Cover is on - No red leds whatsoever
    - Reset CUDA - Done many times
    - PSU - Fans power on, board and card are powered


    - Dead battery - can't check, I don't have a meter handy, cant buy one right now its nearly midnight
    - Dead card - Fans on card are still running and when it removed and machine is powered on the only change is the fan speed in the case, they have slowed down
    - Clean out case - Very dusty, may have cause a failure somewhere bridging something. CBF right now because its nearly midnight here.

    Has anyone had the same symptoms? I've read some posts on this but I'd like to go for some basic checks before I go out and spend more money on this.

    Does this seem like an issue caused by the battery?

    Thanks in advance.
  2. LOLZpersonok macrumors 6502a


    Aug 10, 2012
    Calgary, Canada
    I recall watching a video from Bbishoppcm on YouTube with a Power Mac G5 with the same or similar issue.

    What he did to fix it was to physically bake the motherboard in the oven. He said it was very risky and that there was "about a 75% chance it wouldn't work". It's most likely a logic board issue and I don't know what causes it or if there's a better fix for it.

    Here's the video:

  3. c3rberu5 thread starter macrumors newbie

    Sep 2, 2013
    Thanks for that.

    Its really a mystery, I've gone through a number of posts about similar issues and nothing firm.

    I have a number of Apple products but I am from a pc background and its interesting in the Apple world most "fixes" are replace the logic board. And in the last 20 years with pcs never had a motherboard issue unless it has been physically damaged.

    What I' like to know what it is on the board it self that could've failed so that I can look into it further.

    I've gone through most of the normal post issues because of the no chime except for the CPU's so I'll look into that next.

    Anyone else have any other clues besides reseting something I'd love to try it out.

    If baking works then its a likely a solder issue, something i've come across in xbox 360's. But ill try that next with a heat gun.

    For anyone interested here are pros at work with a proper reball not a reflow on a ps3 same process with most procs.


    Really appreciate the help.
  4. havokalien macrumors 6502a


    Apr 27, 2006
    Kelso, Wa
    Dead processor.

    One of your processors is toast and dead battery issue. I had the same issue. Be careful if you buy a replacement processor as there were two model types. You can try swapping processors as moving the dead one out of the primary slot will allow boot usually, but may kernel panic. Get an ASD 2.5.8 disc as you can check once it boots that the processor will fail its hardware test. I have one set of each type of the 2.0 processors, only issue is I didn't mark which one was bad on each.

    The processor dying is a pretty common issue.
  5. c3rberu5 thread starter macrumors newbie

    Sep 2, 2013
    What kills these procs?

    I've had many pcs and have never had a proc issue. I've seen it happen a few times in the server world, I understand if it were running at 100% util for months but this box doesn't look like it, more of a home use box.

    Interesting because I wouldn't think apple and IBM would produce such unreliable products.

    Ive got an old pentium one which still runs fine to this day.

    Thanks for the info havokalien, from what i've researched it is a complete cpu assembly rather than just the cpu in a socket, has anyone narrowed down an issue within the assembly itself?
  6. havokalien macrumors 6502a


    Apr 27, 2006
    Kelso, Wa
    Not sure

    The moment G5 was released they all had heat issues. They tried water cooling, lots of fans and along with cheap capacitors it was just a wash. That is one of the many reasons for the intel switch.

    I have repaired a few and found no burns on the processors, but always the main processor was at fault. Seen bad solder on ram slot issues but usually processor issue. A few bad capacitors but those are usually on the iMacs.

    Good luck.
  7. 666sheep macrumors 68040


    Dec 7, 2009
    It often was not the CPUs itself, but temperature sensor on daughtercard. It tends to fail and give uber-false read to the logicboard. What caused failed POST (i.e. lack of chime).
    Another possibility is U3 (aka Northbridge) solder joints. Common issue of some series of G5 logicboards. To diagnose it, you'd need to heat-up northbridge with hairdryer for a few minutes, then try to boot. If it would boot after that, you have the culprit.
  8. havokalien macrumors 6502a


    Apr 27, 2006
    Kelso, Wa

    Solder joints on ram sockets is checked the same way.
  9. 666sheep macrumors 68040


    Dec 7, 2009
    After re-reading the OP, I'd say it's 99% dead/incompatible graphics card. Original one is dead, replacement one as well or incompatible.
    Is replacement 6800 Ultra Mac one? It's easy to differentiate PC from Mac one:


  10. flacens macrumors newbie

    Nov 20, 2007
  11. c3rberu5 thread starter macrumors newbie

    Sep 2, 2013
    Thanks for all the replies,

    Thanks for that 666sheep ill look into the fixes you've posted. Much Appreciated.

    It's a mac 6800, longer than the pc version. Was pretty excited to see it in here as my first build was around a x800xt.

    Still not chime when the card is removed.

    Thanks Flacens, looking over the thread now.
  12. alexrmc92 macrumors regular

    Feb 7, 2013
    Check the CPU's for corrosion, this can cause garbled screens and no boot chimes.

    Also checkt to see what LED's are lit on the front of the logic board. It will identify most errors.
  13. 666sheep macrumors 68040


    Dec 7, 2009
    That's perfectly normal. AGP Macs do need graphics card to POST. If card is dead (i.e. its device ID cannot be read by computer) = no card = no chime.
    That's why it works with your old card (not completely dead). Even unflashed PC card is enough to POST, you won't see video obviously.

    On the other hand, PCI and PCIe Macs do not need graphics card to POST.
  14. c3rberu5 thread starter macrumors newbie

    Sep 2, 2013
    Just learnt something new, possibly a dead card.

    Thanks for that 666sheep.
  15. Trystero macrumors newbie

    Jan 23, 2010
    Hello, I had the same troubles on my Powermac G5 early 2005.
    Random: black screen at the startup, kernel panic, crash at the startup after the grey apple logo, no wake up after the stop (in this case the fans became like turbo engines).

    Yesterday I tried a last attempt to fix something, cleaning the interior with compressed air and changing the RAM. And (a miracle!) the G5 started working as it was new. It started perfectly, it wake up after the stop... no more issues of any kind,

    Then I realized that the front fans of the processor were left on the table.
    I placed again in their position and the G5 started with the same defects. I removed them and everything worked fine.

    It 'possible that a malfunction of the fans can really be the cause of all those problems?
  16. jst333 macrumors newbie

    Nov 8, 2012
    Just want to throw this out there. We have a g5-quad that has done this since it was new. Apple replaced the motherboard once, but it kept having the same issues. About every 6 months the g5 would act up, fans blowing no display. A fix that seemed to work us, was to... Start the g5 in target mode, and connect firewire to another ppc mac with the same os. Then on the other mac change the start up disc in sys prefs to the g5, hopefully reboot and then run "onyx"on the g5 disc, then restart. We have an old ibook g4 that we use for this.
  17. guncha550 macrumors newbie

    Oct 31, 2014
    Does anyone knows where to get a working GPU for G5, mine powers up, Mac chimes, I tried a couple ATI and nVidia, GPU's until I found out it has limited GPU support, and I really wish to power it up, but 200 dollars GeForce 6800 Ultra DDL and 450 dollars from Apple, that's a bit too expensive for my wallet, any ideas for other supported GPU's with no less memory than 128-256MB?
  18. repentix macrumors regular

    May 26, 2013
    Had this issue on my 1.8GHz G5 when I bought it a while ago. It happened once or twice in the first days of ownership and after reseating the ram in a different order and reseating the graphics card it happened never again. The previous owner said that you needed to wobble the ram a bit to boot normally which worked for me in the two cases of this issue I encountered.
  19. weckart macrumors 601

    Nov 7, 2004

    I bought a used X1900XT for £12 and flashed it in a spare PC. Working fine for me in my G5 with full Open Firmware support.
  20. guncha550 macrumors newbie

    Oct 31, 2014
    That is PCI-E GPU my motherboard has only AGP slot.
  21. weckart macrumors 601

    Nov 7, 2004
    Same principle applies. I flashed a Radeon 9500 Pro to a 9800 Pro for my Quicksilver. The trick is to have access to a PC with AGP slots, which will be difficult.

    In theory, you can flash on a Mac using Graphiccelerator but that means screensharing with another Mac so that you can see what you are doing. I tried that and it wouldn't work for me. The program ran and gave a confirmation of successful flashing but the card remained unchanged.
  22. guncha550 macrumors newbie

    Oct 31, 2014
    Other Mac PC? No.
    Other PC with AGP slot? Gpt 5 of them, just the problem is I haven't flashed a GPU in my life.
  23. weckart macrumors 601

    Nov 7, 2004
    A decent website to decide on what card you might want to go for is this one.


    As for flashing, there are a few threads on it in this forum. Worth reading those in any event. Apart from that, the technical info is held on this website


    Have a read of that to see whether it is for you but it will save a fair amount of money as Mac video cards still carry a hefty premium. Getting the equipment and files together is the most difficult thing, the flashing process is quite straightforward.
  24. guncha550 macrumors newbie

    Oct 31, 2014

    Thank you, I will try out your advice and hopefully it'll work
  25. guncha550 macrumors newbie

    Oct 31, 2014
    Well I got it with the RAM correctly, it gives me chime, I connected a Logitech Y-UR83 which has Mac support, I power it on, it gives chime, fans on full speed, but for some weird reason only HDD fans are going on full speed, then next what I get is when I looked at motherboard there is a red LED which says DSB, once it's powered, the keyboard does not seem to work at all, as in no LED's turn on the keyboard itself, I got the setup of MacOS Mavericks on a USB flash drive, I press the C button and hold it, but the flash drive doesn't show that it's being read, so tomorrow I am getting 3 pairs of GPU's that are in support list for this specific model but I am pretty concerned, if the motherboard is broken/overheated. I still want to launch that uncle and make it to work tho.

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