2008 Mac Pro won't Boot. Chimes, Black Screen, Video Card Fan at High Speed

Discussion in 'Mac Pro' started by zeratul, Oct 18, 2014.

  1. zeratul macrumors newbie

    Oct 18, 2014
    I have a 2008 Mac Pro Early. I've searched far and wide for this specific problem and posting was my last resort.

    Before it went dead, sometimes it would randomly crash to a black screen and the video card fan would spin at max speed and I would have to power down. Although annoying, I didn't mind it.

    Sometimes on a cold power up, it would do the same thing, black screen, a chime, vid fan at max speed, but after a few attempts of powering it off and back on, it would boot up normally. So I figured I'd just have to deal with this to start it up.

    Now, every time I power up, all I get is a black screen, it STILL chimes, and the vid fan spins at max speed.

    -I have 4 hard drives installed, 2 OS on separate drives. Both Mountain Lion.
    -I dusted the whole thing about 6 months ago, and did it again.
    -I have an ATI 5870 and replaced it with the original NVIDIA 8800, still the fans spin at max speed on startup.
    -I reseated the ram and riser cards. None of the error lights are on. I tried repositioning all 4 ram sticks, and reduced it to 1, substituted all of them.
    -I pressed the LED diagnostic button and no error lights. Says it is in Stand by. LED 8 Green: All power rails are functioning, and LED 9 Green: EFI is done loading.
    -I tried holding CTRL+OPTION+O+F, and CTRL+R, but still nothing.

    FYI: I used this machine for video editing and has maybe rendered 1000? hours of video, give or take. But in the last year, it has not done anything intensive as video rendering. Occasionally Starcraft 2 at high settings.

    So my questions are:

    -does this sound like a bad logic board?
    -could all 4 of the ram sticks have gone bad? although no error lights.
    -could it be something as simple as the power supply?
    -is this thing done?

    Thanks for reading and I'm sorry if I'm posting in the wrong section or is redundant, my first post. Please help.
  2. strophy macrumors newbie

    Oct 13, 2014
    Hi zeratul, after a failed driver update after upgrading to Mavericks, I seem to be having similar problems in a Mac Pro 3,1. Maybe we can help each other out here.

    I had replaced the original Radeon HD 2600 XT with a non-mac NVIDIA 570 GTX and used it successfully for about a year under Mountain Lion. After the driver automatically updated in Mavericks I was getting a grey screen instead of login screen, and then after a while simply no signal. I replaced the original Radeon card, which booted the computer but without any graphics acceleration. Soon after, this card stopped working as well. I was able to get it to boot once by moving the card to another slot, but now I can't get any graphics signal out of the Mac Pro using either card.

    The system still appears to boot fine. If there are no hard drives attached, it will chime, but pressing power will power it off immediately. If the system drive is attached, it will chime and boot, and the power button needs to be held down for a few seconds to get the machine to power off. This indicates that the OS has loaded.

    I tried the diagnostic LEDs you mentioned and got results confirming this, same as you. The EFI LED will light when the system drive is in, indicating that EFI has handed over to the OS. So in total 3 LEDs light: standby (yellow), power (green), EFI (green). The fact that the GPU LED is not lit on both our computers seems to show that the system board has identified a problem with the graphics card. I'm not sure if this LED will light using an after-market GPU, does anybody know?

    I'm going to assume that the original GPU is broken and the NVIDIA 570 GTX isn't. Is it possible to boot the system to USB to install Mountain Lion again? Will it automatically boot from USB if that is the only drive present, or do I need to blindly navigate through the menu after holding down "option"?

    Sources: https://www.scribd.com/doc/17539946/Mac-Pro-Early-2008
    More detailed description of my problem: http://forums.macrumors.com/showpost.php?p=20085803&postcount=1564
  3. OS6-OSX macrumors 6502a


    Jun 13, 2004
    Have you ever taken the PS out and dusted it?

    Attached Files:

  4. strophy macrumors newbie

    Oct 13, 2014
    Hi zeratul,

    my theory from yesterday turned out to be correct. I was able to boot my Mac Pro 3,1 into the installer for Mountain Lion from USB by removing all other drives from the system with the non-EFI NVIDIA card installed. It took about a minute after the chime for any video signal to appear. I'm now trying to find a Mavericks or Yosemite installer that will do the same, so I can run a clean install.

    The only difference between my problem and yours seems to be the high speed fan spinning. But try removing all the system drives until you are in a situation where the EFI LED does not light up, then boot from a USB stick, which will be guaranteed to have clean drivers. I really suspect this whole mess is due to a bad driver problem.
  5. zeratul thread starter macrumors newbie

    Oct 18, 2014

    strophy, thank you for your input.

    I removed all of the drives before and the fan speed was still high.

    The problem was the video card slot. I moved the video card to the other X16 slot and eureka! Something so simple... I feel like a doofus. Hopefully that slot won't go.

    Thanks again!
  6. jpau11 macrumors newbie

    Dec 2, 2015
  7. jpau11 macrumors newbie

    Dec 2, 2015
    Running into the same problem with my 2008 Mac Pro (black screen than fan cranks up high). Switching the video card to another slot causes the system not to boot! Wondering how I can determine if this is the video card issue or the slot issue with the mother board!?
  8. filmak macrumors 65816

    Jun 21, 2012
    between earth and heaven
    Do you have a 8800 GT installed?
    if yes, it's a well known problematic-failing part. Try another card...
  9. MIKX macrumors 6502a


    Dec 16, 2004
    Check : Expansion Slot Utility. System/Library/CoreServices.
    Select a configuration that gives max speed to the location of the GPU.
    I think that in the default config slots 1 & 4 give the best speed for GPUs.
  10. nigelbb macrumors 65816

    Dec 22, 2012
    This is only possible with Mac Pro 1,1 & 2,1. The slot configuration is fixed on the 3,1 Slots 1 and 2 are both x16 revision 2.0 slots. Slots 3 and 4 are both x4 revision 1 slots.
  11. MIKX macrumors 6502a


    Dec 16, 2004
    Thanks for the update, Noted.

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