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  1. #1
    Join Date
    Feb 2012
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    Default Mac Pro not booting

    Hi, I'm new to the forum, having tries a few others in the past, but looking through the posts here, it seems like a good place to come to get some help.
    I've got a Mac Pro 3.0ghz, early 2008 that has a boot problem.
    I've checked all of the ram, no problems showing up there, I've reset the SMC in both ways, I've pulled all of the internal drives, booted off those via USB as well as a couple of others using SL and Lion as well but everything comes up with the same result: it freezes soon after the turning wheel comes up, about 15 secs. The only thing that produces a different result is booting off a SL install DVD... that brings up a kernel panic after a couple of minutes.
    I've reset the PRAM as well.
    That leaves me, as far as I can work out, three possible issues:
    1. Bad ram slot, but the POST check is okay and the LEDs indicate all ram is working.
    2. Bad video card - GeForce 8800GT installed.
    3. Bad logic board.

    The last two are virtually impossible to check without swapping them out and that means potential expense if things have to be sent back, restocked etc, presuming that the supplier will accept them back.

    Any suggestions as to other possibilities or other software that can check the hardware would be appreciated.

  2. #2
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    Feb 2012
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    Default

    I've also booted the AHT and that tells me everything is working properly... fat lot of good that has ever been!

  3. #3
    Join Date
    Aug 2001
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    Default

    So I have thought on this for a bit... wondering what I would do.... that you haven't. I cannot think of much. Only thing to try is start disconnecting stuff - like hard drives and memory. Generally, when it gets down to the list you have it almost is impossible to do anything without swapping in other parts. Which means an Apple Certified Repair guy. They will be able to swap in a graphics card, memory, motherboard until they locate the problem.

    I don't know any tricks. Might, just maybe, be a small chance that the Kp Log would reference something useful. However I have not very often seen anything that allowed me more than a guess.

    Welcome to the forum. Couple of our folks here are really good at this stuff and will most likely weigh in.

    Rick
    molṑn labe'
    "I am a mortal enemy to arbitrary government and unlimited power. I am naturally very jealous for the rights and liberties of my country, and the least encroachment of those invaluable privileges is apt to make my blood boil."
--Ben Franklin

  4. #4
    Join Date
    Jan 2002
    Location
    NW Montana
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    Default Welcome to the Guru's Forums

    You've found the right forum. Now we just need a smarter Moderator. The smart guy just beat me.

    I don't fully trust all the "various test apps" they might say "good" when they really are not.

    Was any of the RAM recently added? Or any other new hardware or software.

    I'm not very familiar with that specific computer but RAM can create many issues. I don't recall how you need to put the RAM in but if you can just use 1 stick or 1 pair try different slots to see if indeed there is a bad slot or even a bad RAM chip. A little time consuming but effective.

    If you can create a "new user" and see if the issues still happen this will eliminate a /users issue or corrupted /users file.

    If you have DiskWarrior and it boots let it run.

    Others will be around hopefully with a better thought. You have hit the obvious or first troubleshooting tips or advice.

  5. #5
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    Mar 2001
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    Default

    the POST check for ram isn't a good indicator of whether your ram is actually working. Also bad ram will manifest itself as a problem with everything in your system BUT ram. It will not boot sometimes and boot fine other times only to act like a bad hard drive. Later it acts like the vid card then another time like the optical drive. I had this happen on a Mac Mini a year or so ago. Very hard to diagnose.
    Damien,

  6. #6
    Join Date
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    on the landline, Mr. Smith
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    Default

    So, you said you tried some other boot volumes as well......clean install of a retail OS? Just want to be sure there is no chance it could be an OS/software issue.

    Hardware - I would tend to agree: strip it down to minimums; 1 HD, 2 sticks of RAM. Rotate slots and sticks to see if one is bad, and rotate the HD to at least one other slot or external.

    If you running 10.7, you could boot from the recover partition to see what you get......would be nice to boot from the internet recovery option, to remove the entire SATA/USB/Firewire bus. But only the latest hardware is supported, so far.

    Oh, and did you do the extended AHT?

    Next, odds are on the graphics card. Any chance you can come up with a loner?

    Apple repair centers have a very handy AST netboot version of AHT that might shed some light on the diagnosis too.....if you are anywhere near an Apple store or certified Apple Repair Center (reseller).
    "Imagine if every Thursday your shoes exploded if you tied them the usual way. This happens to us all the time with computers, and nobody thinks of complaining." -- Jef Raskin

  7. #7
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    Found this about the 8800 in MacPros:

    The NVIDIA GeForce 8800 GT video card requires Mac OS X v10.5.2 or later and the Leopard Graphics Update 1.0 for proper function. Since some media do not include the appropriate drivers and updates, the computer may start up to a gray screen or kernel panic as a result. Potentially affected media include bundled restoration media and earlier Mac OS X v10.5 retail media.

    To reinstall Mac OS X or start up from the optical drive, follow these steps:

    • Remove the NVIDIA GeForce 8800 GT video card.
    • Install a supported graphics card, such as the NVIDIA GeForce 7300 GT, ATI Radeon X1900XT, or NVIDIA Quadro FX 4500.
    • Start the computer from the Mac OS X media and reinstall the operating system (or perform other tasks as necessary).
    • If Mac OS X has been reinstalled, reboot from the hard drive, update to at least Mac OS X v10.5.2 with Leopard Graphics Update 1.0.
    • Reinstall the NVIDIA GeForce 8800 GT video card.
    "Imagine if every Thursday your shoes exploded if you tied them the usual way. This happens to us all the time with computers, and nobody thinks of complaining." -- Jef Raskin

  8. #8
    Join Date
    Jun 2012
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    4

    Default Early Mac Pro not booting HELP!!!!!

    Hi all,
    I have an early mac pro which I have diagnosed to the best of my abilities by following the advice in some of these threads.

    I have narrowed down to this:
    with all devices removed ie graphics card, HD and RAM the following is observed on the diagnostic LEDs.

    No diagnostic leds are lit. Pressing the diagnostic button causes ONLY the trickle power LED to light and nothing else. Fans are going non stop so indicates PSU is ok. I have read elsewhere that capacitors on MB where power enters can blow and need replacing. How would I check for this? And exactly which capacitors do I need to check?
    thanks in advance for any help,
    greg

  9. #9
    Join Date
    Feb 2012
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    265

    Default

    Ah, this has just brought the thread live again.
    I had the cards replaced as there were no capacitors that could be replaced even if I could have identified them.

    GG23... if you are going to get involved in component level repairs you need an awful lot of information and a hell of a lot of luck.
    Most of the components on the logic board are unidentifiable as they are not generic components so even if you were able to diagnose a problem the chances of you fixing it are virtually nil.
    Once a logic board has been determined to be the problem 999/1000 you will either get a new logic board, if the value of the Mac is high enough to warrant the expense, or you will write it off and sell it for parts.
    As it's a Mac Pro, it will still have a relatively high value, but then so will a logic board.
    Current price of a 2008 logic board in the UK is 295 so it would still be worth doing.

  10. #10
    Join Date
    Jun 2012
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    Default

    hi macloon,
    Thank you for the reply. Do the symptoms indicate that it definitely IS the MB. Is there any way of confirming this other than swapping in a whole new MB?

    Thanks
    greg

  11. #11
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    on the landline, Mr. Smith
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    Exactly which model is it?

    I expect the loon is right, but we can dig a little to see if there are any other options.
    "Imagine if every Thursday your shoes exploded if you tied them the usual way. This happens to us all the time with computers, and nobody thinks of complaining." -- Jef Raskin

  12. #12
    Join Date
    Jun 2012
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    Default

    the machine has numbers A1186 and MA356LL/A so Im asuming its a 2008 model 2.66Ghz dual Core

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