Scraped an op amp from logic board accidentally

Discussion in 'Mac Pro' started by Raunien, May 8, 2019.

  1. Raunien macrumors 6502

    Joined:
    Aug 3, 2011
    #1
    Hi all,

    I went to remove a graphics card power cord from one of the 6pin modules on the logic board and accidentally took off what looks like an op amp from the logic board (see picture).

    It is UE001 and had an "A219" op amp originally.

    The machine still turns on and runs without this. Does anyone know what this does and if it is absolutely necessary for it to run? Has anyone had any experience resoldering things like this back on? Or should I get another logic board?

    Thanks for all the replies.
     

    Attached Files:

  2. tsialex macrumors 601

    tsialex

    Joined:
    Jun 13, 2016
    Location:
    Brazil
    #2
    Did you checked if you still have readings for the PCIe Fan? If I remember correctly, I'll confirm it later, that part of the PCB is related to sensors.

    I can't see clearly on the photo, but seemed that the pads were ripped off too, no?
     
  3. Raunien thread starter macrumors 6502

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    Aug 3, 2011
    #3
    PCIe fan is still working properly and reading speed properly - able to adjust. All temperatures are also reading correctly that I know of.

    Using iStat Menus.
     
  4. tsialex macrumors 601

    tsialex

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    #4
    I can't see clearly on the photo, but seemed that the pads were ripped off too, no?

    Without the pads, you can't solder the IC back, but you can epoxy glue the IC then re-do the connections with 30AWG kynar wire.
     
  5. Raunien thread starter macrumors 6502

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    Aug 3, 2011
    #5
    Yes the pads were ripped off too :(. So you wouldn't recommend running without fixing this? (I think I know the answer already)
     
  6. tsialex macrumors 601

    tsialex

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    #6
    If you are in the US, the cheapest way to repair is just to replace the backplane. You can buy backplanes for around $50 + shipping. If you are somewhere else in the world where Mac Pro parts still have stupid prices, then you can try to repair.

    I would find the function of that part of the circuit before using the Mac Pro. I can take a look tonight, no backplanes here at work.
     
  7. Raunien thread starter macrumors 6502

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    Aug 3, 2011
    #7
    Thanks I will probably do that. I wanted to find out the function too but couldn't find a schematic.
     
  8. bsbeamer macrumors 68020

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    Sep 19, 2012
    #8
    Search "Apple Mac Pro Technician Manual" on your favorite search engine. It'll show up as one of (if not the) top result.
     
  9. tsialex macrumors 601

    tsialex

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    #9
    It's something sensor related, could be PCIe AUX A current/voltage sensor. All iStat Menus sensors still work?
    --- Post Merged, May 8, 2019 ---
    Mac Pro Service Manual don't have the component schematic needed at this level, unfortunately only the block diagram.

    Btw, no third party made a MP4,1 or MP5,1 schematic yet and the real ones from Apple never leaked.
     
  10. Raunien thread starter macrumors 6502

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    Aug 3, 2011
    #10
    As far as I can tell, all sensors haven't changed from what what it was before. PCIE Aux A current still reports the same as it did before.
     
  11. W1SS macrumors 6502

    W1SS

    Joined:
    Aug 20, 2013
    #11
    I had something similar happen to me with the processor board, was a very sad day. Once the pads are off, the only way to solder the mosfet back on was through wires soldered to the traces which were then soldered to the mosfet.

    I could't live with it knowing the ugly repair was there so I ended up ordering a new board. In your case, a used backplane is the best route unless you find a new one for a good price.
     
  12. Raunien thread starter macrumors 6502

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    Aug 3, 2011
    #12
    Thanks, that's probably what I will do.


    This is the part that was used in the mac pro and it sounds like it is used to monitor current.
    http://www.ti.com/product/INA219
     
  13. tsialex macrumors 601

    tsialex

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    #13
    This bothers me deeply too, every time I damage a pad it's the same. Sometimes you can make a good looking repair and you eventually forget about that, but when you can't…
     
  14. W1SS macrumors 6502

    W1SS

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    Aug 20, 2013
    #14
    It's game over for the board.. I actually still have a dual 4,1 tray that I used as a donor to salvage the mosfet from, and of course the old 5,1 dual tray... Not sure if they're worth anything now.

    @Raunien, if you are keen on repairing the board you can try Louis from Rossmann Group in NYC. I love watching his repair videos on youtube and if there is one guy that knows this stuff, it's him. He has tons of schematics.

    Edit : Just saw your reply... Seems to be a power sensor of sorts.. Personally, I'd power off the mac until the replacement backplane arrives or repair is carried out.
     
  15. crjackson2134 macrumors 601

    crjackson2134

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  16. tsialex macrumors 601

    tsialex

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    #16
    Any professional repair will cost multiple times the going price for a backplane on eBay.

    Even if the technician has magic repair skills and the correct PCB repair pad replacement, they exist for some very expensive boards repairs like for medical imaging equipment, you will still know that the PCB pads were repaired.
     
  17. mrtang42 macrumors member

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    Apr 19, 2019
    #17
    Louis doesn't do cMP, because he doesn't have any schematic for cMP logic boards. Plus the repair cost is very expensive.
    --- Post Merged, May 8, 2019 ---
    Go eBay. That's the best low cost option. cMP is too old to repair.
     
  18. Raunien thread starter macrumors 6502

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    Aug 3, 2011
    #18
    Already went ahead and bought a replacement board - thanks everyone for the advice.

    Would still love to know the function of this piece though! Always curious.
     
  19. macguru9999 macrumors regular

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    Aug 9, 2006
    #19
    My backplane was $150usd from LA , postage was the killer unfortunately .... i am in sydney
     
  20. spidertnt, May 8, 2019
    Last edited: May 8, 2019

    spidertnt macrumors member

    Joined:
    Aug 11, 2014
    #20
    I have repaired a few of these pretty common problem ...customers installing video-cards requiring dual power .

    They try to remove power connector...when it releases it travels along the board surface knocking off one of those IC chips.

    Once repaired i have covered them with a drop of epoxy.

    Pretty sure it's part of the power circuit for the 6pin power. Client was having trouble with his video-card . That chip was missing once replaced it worked correctly.
     
  21. Raunien thread starter macrumors 6502

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    Aug 3, 2011
    #21
    @tsialex anyway to flash my old serial number onto the new logic board (to match up with the outer case)? I understand that the new one will come with its own serial number.
     
  22. startergo macrumors 65816

    startergo

    Joined:
    Sep 20, 2018
    #22
    Why don't you run AHT test? Put an Apple card inside and try it. I also have an issue with Istat not reading the current from the A boost. Maybe I should inspect my circuit too.
     
  23. tsialex macrumors 601

    tsialex

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    Jun 13, 2016
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    Brazil
    #23
    It's not straight away.

    You have to keep the MLB/LBSN sector from the replacement board and just use the 3rd and 4th streams of the NVRAM of the old board or Apple will block iCloud/Messages/FaceTime.
     
  24. MIKX macrumors 6502a

    MIKX

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    Dec 16, 2004
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    Japan
    #24
    Perhaps those of us whom have recently been removing the cMP onboard 6 pin cables should check for any similar damage on their motherboards. Mine is OK
     
  25. Raunien thread starter macrumors 6502

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    Aug 3, 2011
    #25
    Ah okay, sounds more complicated than I anticipated. I will probably just deal with the new serial number.
     

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