Mac Pro 4,1 upgraded to 5,1 wont boot

Discussion in 'Mac Pro' started by databaze, Apr 14, 2017.

  1. databaze macrumors member

    Joined:
    Nov 21, 2011
    #1
    I hope someone can help me with this issue. I have a Mac pro 2009 4,1 that was flashed to 5,1 before i bought it. It has had some issues with kernel panics, sudden crashes, etc, never any indication of what the cause may be.

    Usually it freezes and then i just do a hard reboot and comes back up, but yesterday, it froze, did a hard reboot and since then it just won't boot.

    The front power button led illuminates, fans turn on but nothing happens.

    I got the service manual pdf and looked up the diagnostic led chart and this is what I get:

    When the power cable is unplugged and I plug it back in, I get the two CPU diag leds to flash red for less than a second, and then if I press the DIAG button i get what you can see in the attached video.

    I have removed the CPU tray (no red lights on any of the ram modules, CPU leds flash red when powering up but do not stay lit) and re-seated all ram modules, I removed the video card and swapped it for another one that I know works on another Mac Pro I have and that is as far as I can make it.

    Any ideas, recommendations, etc would be more than welcome, I really don't want to buy another one with the supposed new ones maybe coming up next year but if i can't figure it out I may have to.

    Thanks!

    PS: I just swapped the 3v battery and the flashing green DIAG led is now not flashing anymore and stays lit. Still no boot.

    VIDEO 1: Flashing Green led--->https://vid.me/iIgH

    VIDEO 2: After swapping 3V battery, green led no longer flashing----->https://vid.me/yaOo

    VIDEO 3: You can see all leds that flash when power cable is plugged/unplugged, power button is pressend to boot/turn off------>https://vid.me/6RS9

    I hope anyone comes up with ideas :)
     
  2. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #2
    Apple staff said this problem usually due to PSU, logic board, or GPU failure.

    Since the Mac Pro can boot without the GPU. And you already tested it. So e can rule out the GPU.

    Next one is the PSU. However, from the Mac's strange behaviour before fail. I bet it's not the PSU as well.

    So the remaining items are logic board / CPU tray. It's hard to tell which one is the root cause if there is no another Mac Pro / parts for substitution test.

    One of the known weak point of the cMP is the north bridge. You should check if the north bridge heat sink still firmly attached by the rivet.

    Anyway, if there is any Apple Store next to you, you can always take the Mac Pro to there for free checking / diagnosis. In my own experience, they don't care if it's a flashed Mac
     
  3. databaze thread starter macrumors member

    Joined:
    Nov 21, 2011
    #3
    There was something bothering me since i got this Mac Pro, and that was that, every time it would be on, it would smell like something sweet, like gum or something, kind of like fabric softener, but I could never pinpoint the issue or where the smell came from.

    I decided to take the PSU off the case and, well, the smell comes from it. I made a video showing the inside of it, not sure if the amount of glue? (yellow substance) is over the top or what, but the PSU definitely smells like gum/fabric softener.

    Regarding what you said: So the remaining items are logic board / CPU tray. It's hard to tell which one is the root cause if there is no another Mac Pro / parts for substitution test.


    The CPU tray is new, I had to get a new one less than a year ago because the guy that owned this Mac Pro bent the pins on the CPU socket and I was getting CPU led errors, after I swapped it, it has been working fine as far as I can tell (well, with the constant freezes, it could be the back plane board too...). I would say that the north bridge should be ok as well since it is a new board, as far as the logic board, well, I did not change that one, but If I were to do that, I would have to get new CPU's to be able to flash it to 5,1, which would be a pain in the ass.

    I'll see if I can get a new PSU and try to see if that was the issue, if not, I'll just take it to the Apple Store and see if they help, I wanted to run an AHT but it won't even chime so I can boot to USB either..

    This is the video of the PSU inside---------->https://vid.me/81VG
     
  4. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #4
    I never open up the PSU, can't tell what it is, and can' tell if that's normal (even though it doesn't looks "normal"). May be some PSU expert here can tell you the answer.
     
  5. databaze, Apr 14, 2017
    Last edited: Apr 14, 2017

    databaze thread starter macrumors member

    Joined:
    Nov 21, 2011
    #5
    Yeah me neither, I've seen a couple of videos and none of them show that much of that thing on the PSU, anyone around that could show some light on this? I was thinking about buying another PSU just to test, but if that does not work, then...
     

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