Power Supply failure or something else? How to make sure?

Discussion in 'Mac Pro' started by iBug2, Oct 6, 2009.

  1. iBug2 macrumors 68040

    Jun 12, 2005
    Ok here's the deal. Early 2008 Mac Pro Octo 2.8.

    First one of the hard drives fail, couple days later 8800gt starts showing artifacts and crashes, and doesn't boot again on Mac OS X. (Boot starts but system hangs during boot)

    Boots on windows with lots of artifacts on screen and no acceleration whatsoever. Windows reports the card as broken.

    So I think it's the card. I order GTX285. The card arrives today, I put it in, everything is fine, Mac OS X boots, I'm playing games, superfast card blah blah. The computer shuts down suddenly. Like someone pulled the plug. It doesn't crash, just full shutdown abrubtly. I try to boot, NOTHING happens when I hit the power button. It doesn't even light up.

    I disconnect the power from the GTX285, I hit power button, it boots (but ofc it boots without a video card, but everything is working since I can make sure I get the desktop by pushing control+eject > enter to shutdown the system. So without GTX285 powered, system boots. With GTX285 powered, nothing happens. I open up the computer, I look at the logic board, when GTX285 is powered, when I hit the Power button, a red light on the logic board, right beside the power cables going to the card, lights up really fast, and like I said nothing happens. I call my Apple guy, he says that red light means a power issue, that the machine doesn't have enough power to power up the card, so nothing happens. It doesn't even start the boot process.

    I disconnect hard drives, optical drive etc, anything that needs power, and try to boot with GTX285, still nothing. So me and my Mac guy (on the phone) decide it must be the power supply. So I take the mac to the service here in my city. They say 1 week wait time for diagnostics etc.

    So do you guys think it's the power supply? Before all this happened, (hard drive failure, 8800gt failure) there was a power surge kind of thing, power went down and up really fast, but the Mac Pro shut down, and although it's connected to a Monster Powercenter (some protection for power surges), my Mac guy said that kind of stuff can easily damage the power supply, and Mac Pro's really use a crappy supply which doesn't help.

    So I'm just gonna wait and see what the service finds out.

    But has anyone experience something like this before and if so, what to do to protect the Mac Pro from such power surges? I mean if even with a surge protector this can happen then what?

    (Again, assuming it's the supply, but what else can it be? The system perfectly boots windows with the broken 8800gt, and although there are artifacts all over the screen, everything works. So the CPU/logicboard/ram are obviously doing ok)
  2. gugucom macrumors 68020


    May 21, 2009
    Munich, Germany
    you can diagnose the LEDs with the test button to see if you still have trickle power and that is about it. From there diagnosis goes by exchanging components.
  3. TheStrudel macrumors 65816


    Jan 5, 2008
    Is there a "click" sound when it fails to turn on?
  4. iBug2 thread starter macrumors 68040

    Jun 12, 2005
    Yes there is.
  5. nanofrog macrumors G4

    May 6, 2008
    I'd go ahead and wait until Apple's done with it. I think the GX285 is shot, and presents too high a load (wants too much power) off the PSU. Unfortunately, this can damage the PSU as well (and may have), and that can then damage other components, such as the 8800.

    Presuming you still have Apple Care, they'll replace the PSU and 8800 if they're damaged. Then you'd have to deal with the manufacturer of the GTX285 on your own, assuming it's still under warranty as well. ;)
  6. iBug2 thread starter macrumors 68040

    Jun 12, 2005
    The GTX285 definitely draws more power than 8800 but 8800 died way before 285 arrived. I purchased 285 after 8800 died. So 285 did not damage 8800.

    And although 285 draws more power, EVGA 285 is officially sold through apple store so it's supported by Apple on Mac Pro early 2008. So the PSU should not have any problems if Apple officially supports the card.

    Like I said, I'm assuming the PSU got damaged and then it started damaging other components like that hard drive and then 8800 and now finally the failure is so bad it won't even start when 285 is connected.
  7. TheStrudel macrumors 65816


    Jan 5, 2008
    The click is the smoking gun of a power supply failure. I've witnessed it before in G5s, among other computers. If you take it to an  store, they will likely tell you the same thing.
  8. nanofrog macrumors G4

    May 6, 2008
    I wasn't sure where you got the GTX285, and figured it may have been from another vendor/etailer, requiring it to be sent back to EVGA directly for warranty claims (ye olde RMA). ;)

    I presume you got it from Apple then, and they should replace all 3 parts for you (PSU, 8800, and GTX285). Easy, but you'd have to wait for the diagnostic to be completed, the parts to arrive (they'll have to order them), and then the repair. Sucks, but it won't cost you anything. :D

    A failed device can kill a PSU as well (too high a current draw). But either way, it would be covered, as the parts all originated from Apple. So they can't give you any grief over it if they wanted to even try. :p

    It's common, but IIRC, I've heard the relay/s "click" when it was as simple as a blown fuse to a bit more critical, such as a fried transistor in one of the rails. :(

    So though it's a good indicator that the PSU isn't doing it's job of delivering power, all may not be lost. If you're lucky of course, and it's the fuse. :p
  9. iBug2 thread starter macrumors 68040

    Jun 12, 2005
    I'm pretty sure 285 isn't damaged at all. I only used it for 1.5 hours and then the computer shut down. I doubt during the shut down the card got damaged at all. There were no indications of damaged video card before shut down (triangles, jagged lines etc).

    And Apple won't do it for free since it's almost 2 year old machine and I don't have Apple Care. Doesn't matter though. The PSU costs around 200$ when Apple Store does the repair, for an almost 3500$ machine it's a small price to pay. I'm just hoping it's only the PSU. If it did damage the 285, then I'll have to deal with that as well.
  10. iBug2 thread starter macrumors 68040

    Jun 12, 2005
    Or do you think it's possible that there was something bad going on within the card, 285, that is causing a short circuit when connected, so the PSU doesn't power up anything? Although the 285 probably died because of a broken PSU in the first place, again, if it died.
  11. nanofrog macrumors G4

    May 6, 2008
    Hopefully, that's the case, and you won't have to cough up for another.

    Keep in mind though, a bad PSU can take things out with it.

    Ouch. Extending Apple Care is a really good idea, considering what Apple charges for parts/repairs.

    Last I checked (macpalace.com), the cost of the PSU was closer to $300. So if they only want $200 installed, that's actually a bargain. :eek: :p

    Will you even bother with 8800 then, as the 285 works for both OS's?
  12. iBug2 thread starter macrumors 68040

    Jun 12, 2005
    No I won't bother to replace 8800 if 285 is working fine after everything is repaired. But it's a good idea to keep a working secondary video card around, although I might just get the cheapest card out there for Mac Pro's for that, not a new 8800. And about the price of PSU, I didn't ask them the price yet, but I'm just assuming it'll be cheaper than 300$ (which is end user price). My Mac guy told me that apple charges less when they do the repair themselves.
  13. nanofrog macrumors G4

    May 6, 2008
    Hopefully it won't be terrible cost wise.

    As per a second card, you could follow the Flashing or injector threads in order to save some money. ;)
  14. iBug2 thread starter macrumors 68040

    Jun 12, 2005
    Yes I'm thinking the same thing. And also if my power supply is actually the only damaged component, like I said I got a pretty good idea how it damaged. And although the computer was connected to a Monster Powercenter HT800, it didn't help much. I need to find a better surge protection and voltage regulation component to avoid future incidents.
  15. nanofrog macrumors G4

    May 6, 2008
    You need a good UPS. ;) It works with both surges and brown outs (low voltage conditions), which are much more common and are just as damaging. They tend to damage over time, but they're usually so frequent, the damage is actually more common than from a surge. Statistics at work. ;) :p

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