What backplane boards work in Mac Pro 5,1 ?

Discussion in 'Mac Pro' started by Jdebunqe, Apr 17, 2017.

  1. Jdebunqe, Apr 17, 2017
    Last edited: Apr 17, 2017

    Jdebunqe macrumors newbie

    Jdebunqe

    Joined:
    Apr 17, 2017
    #1
    I have a 2010 Mac Pro 5,1 with a quad 2.8 GHz CPU.

    The backplane board is dead.

    I want to salvage this machine, cheaply. But 5,1 logic boards are expensive ($300). A 4,1 board costs only about $120. It's the same part number, but EEE code is BH9, different from 4,1 boards.

    Is there any chance that a 4,1 (2009) board will work in an otherwise 5,1 machine? This is a 2010 with the lowliest old-style CPU, so my thinking is that it MIGHT not need the new CPU support of the 5,1 backplane.

    Would the machine work with a 4,1 backplane with upgraded firmware? Would it boot enough to upgrade the firmware (given the old-style CPU), or would the firmware upgrade have to be done beforehand on a 4,1 machine?

    Finally, what is the underlying difference between between an upgraded 4,1 backplane and a genuine 5,1 backplane? I heard something about the fans running full all the time, because of different SMC firmware. Can this be upgraded too? I've read that a 4,1 backplane is forever a 4,1 even if upgraded? Is this true, and why?

    Thank you for any tips, or any link that explains these issues in detail.
     
  2. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #2
    No, the SMC firmware won't match. If you buy a 4,1 logic board, you have to buy a 4,1 CPU tray as well (including the heatsink etc).
     
  3. Jdebunqe thread starter macrumors newbie

    Jdebunqe

    Joined:
    Apr 17, 2017
    #3
    This is the rough answer I've seen already, but the nitty gritty questions I'm really interested in are

    1. is SMC firmware something that can be upgraded?
    2. is the minimal 4x2.8 2010 CPU tray the same as a similar 2009 board (this is the barebones CPU that didn't change, if I understand correctly)?
    3. Will firmware mismatch result in a non-boot, or merely problematic operations (eg fans on all the time) that will permit a firmware flash?
    4. If (question 1) you can upgrade SMC firmware as well as board firmware, can you turn a 4,1 logic board into one that is indistinguishable from a 5,1 board?
    5. This one is far out - is there a chip that can be swapped from the dead 5,1 board to put the new firmware on a 4,1 board?

    Is there a site that fully explains these firmware issues?

    This site: https://support.apple.com/en-us/HT201518 seems to suggest that there are no SMC versions for a 4,1 or 5,1.
     
  4. Filin, Apr 17, 2017
    Last edited: Apr 17, 2017

    Filin Contributor

    Filin

    Joined:
    Mar 7, 2010
    Location:
    Ukraine
    #4
    1. Last firmware for 4.1 has different SMC version (1.39F5) than 5.1 has (1.39F11). And after hack upgrade from 4.1 to 5.1 version of SMC remain the same (1.39F5). Not known, how to update SMC version from 1.39F5 to 1.39F11
    2. There is no 4 CPU tray. Only single and double. Dual CPU trays a very similar, but have different heatsinks (not interchangeable).
    3. It should boot, but all fans will go crazy. You can flash firmware, but firmware will not change SMC
    4. SMC cant be upgrade easy
    5. Sure, but it soldered on board.
    --- Post Merged, Apr 17, 2017 ---
    Try read here http://forum.netkas.org/index.php/topic,13595.0.html
     
  5. Jdebunqe thread starter macrumors newbie

    Jdebunqe

    Joined:
    Apr 17, 2017
    #5
    Thanks! I meant "4-core 2.8 GHz tray" when I confusingly wrote "4x2.8 2010 CPU tray".

    This is the information I was looking for: that the 4,1 and 5,1 boards are identical, but it is not possible to change the SMC firmware. It seems that anyone who figured out how to convert 4,1 boards to 5,1 with chip update would make some nice cash.

    Is there any info about which chip the SMC firmware lives on? In case I get drunk enough to mask off the board and hot-air the chip off the old board and onto a cheap 4,1 board?
     
  6. ActionableMango macrumors 604

    ActionableMango

    Joined:
    Sep 21, 2010
    #6
    Just a thought, but are you certain the backplane board is dead and not something else like the power supply?
     
  7. Filin Contributor

    Filin

    Joined:
    Mar 7, 2010
    Location:
    Ukraine
    #7
    You should look "board view" file for 820-2337
    It not easy to find (for free).
     
  8. Jdebunqe thread starter macrumors newbie

    Jdebunqe

    Joined:
    Apr 17, 2017
    #8
    Power supply and cpu board work in my other 2010 mac, and it fails the "strip down machine and jumper contacts X and Y so the fans spin" test from the service manual.
     
  9. Filin Contributor

    Filin

    Joined:
    Mar 7, 2010
    Location:
    Ukraine
    #9
    Good news, i found SMC IC. And its not BGA! :)
    Same IC located on CPU board.

    IMG_3568.JPG
    IMG_3573.JPG
     
  10. Jdebunqe thread starter macrumors newbie

    Jdebunqe

    Joined:
    Apr 17, 2017
    #10
    Thanks ... I ended up getting a cheap 2010 backplane and it fixed my machine very nicely.

    If you could figure out how to reprogram this chip, you could probably earn $70 a board turning 4,1 into 5,1!
     

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