Small Part Fell Off the Logic Board. What is it?

Discussion in 'MacBook Pro' started by Arta0613, Sep 9, 2013.

  1. Arta0613 macrumors newbie

    Joined:
    Sep 9, 2013
    #1
    Hello to everyone, I'm a new user. Today I have had an issue come up that needed urgent attention so I am posting this thread. Usually I find what I'm looking for by searching, but I couldn't find anything regarding the problem at hand which is why I'm posting. I have a Macbook Pro Late 2011. I bought the OWC data doubler bundle. It comes with a hard drive, caddy, and tools for the job.

    When trying to take the screws that held the bracket keeping the airport and blue tooth cables, I managed to strip then. After applying a lot of pressure, I was able to extract the screws. In the process, I unknowingly may have loosened a small part on the logic board. After installing the second hard drive and turning my mac on, I checked disk utility to format the disk. Everything seemed fine so I turned my Mac over to screw the backplate back up. When I turned it over, I heard a clink on the backplate and I thought it was a loose screw even though I made sure the screws were snug. So I took the backplate off and I see a small part of what I assumed to be a transistor, lying there. I say small part instead of transistor because I really don't know what it is. I'm attaching an image of what it looks like. In the image, there is some text saying Power-on Pads. The small part I'm talking about is in between the a and the d of the word "pads". It might be a little unclear, if so, I'll take a picture of the part and post it up. Here is the image:

    [​IMG]

    Only the top part had come off. I haven't turned on my mac since I saw that. I'm writing this on my tablet. If anyone knows what this piece is, can you please let me know. And also, would it be okay to solder it back on? What have I done to my machine now that it's off? What steps should I take to fix this?

    Thank you for reading.
     
  2. Shrink macrumors G3

    Shrink

    Joined:
    Feb 26, 2011
    Location:
    New England, USA
    #2
    Ah...it's probably just an extra part Apple threw in...just toss it. I'm sure you don't need it!:p ;)

    Sorry, couldn't resist. I'm sorry that I can't help you regarding the part...I'm sure someone here will help you out.

    Good luck with the part...:D
     
  3. laurihoefs macrumors 6502a

    laurihoefs

    Joined:
    Mar 1, 2013
    #3
    If you are referring to the brownish "bricks", they are SMT capacitors.

    They seem to be in the proximity of an FPGA made by Lattice, so are very likely related to it. I have no idea what the function of that FPGA could be, but it is possible that it will still function, if the other capacitor is there. But repairing it might still be a good idea.

    SMT components have a nasty tendency to rip their solder pads off with them, if knocked loose. If that is the case, soldering the capacitor back might be a chore. But if you see the pads still attached to the board, it should be pretty easy to solder it back on with the proper equipment. I would not recommend doing it yourself, if you have no experience of SMT soldering.

    Any repair shop that does SMT soldering should be able to help you.
     
  4. Arta0613 thread starter macrumors newbie

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    Sep 9, 2013
    #4
    Thank you.

    By solder pads, I'm going to assume you mean the black stuff on the board? The capacitor doesn't seem to have any residue. Here is an image of my board and capacitor. I took a picture of the side where it looks like it was placed.

    [​IMG]

    [​IMG]

    I definitely don't want to try doing it myself so thanks for letting me know what it was. So there are the pictures, do you think the solder pad was ripped off?
     
  5. jav6454 macrumors P6

    jav6454

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    #5
    I see where it goes. It is not extra, and yes it fell off. How did you notice this? Can you get a closer look of the first picture?

    Specifically the area around the highlighted red circle. I need the best zoom in to that area. Also a good picture at the capacitor itself. With that I can tell you honestly if this is an Apple issue and what to do to fix it or if its not fixable.
     

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  6. laurihoefs macrumors 6502a

    laurihoefs

    Joined:
    Mar 1, 2013
    #6
    Solder pads are the contacts on the PCB that the component is solreded on.

    It's very hard to say if the pads are damaged or not, from this picture I'm not sure it the brown parts on the pads are broken off from the capacitor, or if it's the bare PCB that was under the pads.

    Either way there appears to be enough of the pads left/undamaged to solder a capacitor back on!

    So take the laptop to a company that has SMT soldering equipment, and you'll have it fixed in no time :)
     
  7. jav6454 macrumors P6

    jav6454

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    #7
    It appears (like you said) that the pads are intact; however, I'd rather OP give us a closer look to the area I circled previously.

    That should give us a clear idea what is truly wrong.
     
  8. nickandre21 macrumors 6502a

    Joined:
    Jun 21, 2012
    #8
    well if the pads do not seem shorted then you could try starting the mac up to see if it powers up and if you face any issues as such. If you do then do try looking for a replacement part and have someone solder or else keep the part and continue using it.
     
  9. Arta0613 thread starter macrumors newbie

    Joined:
    Sep 9, 2013
    #9
    Thanks for replying. I noticed it when I took the back plate of and it was lying on the battery. I liked for other pieces like it and saw similar ones.

    I'm including pictures that I took last night. I tried getting closer but it kept getting blurry. This is the closest I got without it getting blurry.

    [​IMG]

    [​IMG]

    [​IMG]
     
  10. jezzy macrumors member

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    Jan 12, 2012
    Location:
    Montreal, Quebec
    #10
    pads look big enough to be able to re-solder it back in place. if not by you, someone else with the proper skills.
     
  11. jav6454 macrumors P6

    jav6454

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    #11
    I'll be straight forward. The pads look ok. However, the capacitor is obviously damaged. Why? If you look at the left over solder, you'll notice a brownish material there. Well, that is actually part of the ceramic of the capacitor itself.

    In other words, part of the capacitor was left over at the solder points. Given this fact, the capacitor might not be the nominal value it needs to be. Example, if the capacitor is 11nF; however, due to damage, it is now at 9nF.

    Small changes like that can mean a lot of difference in the world of microelectronics. So given that, I would not advice you to solder it back in there. However, if you can obtain a capacitor that replaces the one that fell off, then yes go ahead and do an SMT soldering there.

    However, given that SMT soldering is tedious and you have the risk of destroying the pad, I would suggest first go to Apple and show it to them (hopefully you still have warranty). If no warranty, then SMT is the only option.

    Yes, I still think using your Mac without that capacitor is a bad idea.
     
  12. laurihoefs, Sep 11, 2013
    Last edited: Sep 11, 2013

    laurihoefs macrumors 6502a

    laurihoefs

    Joined:
    Mar 1, 2013
    #12
    This looks consistent with damage caused by physical force, for example a slipped screw driver.

    It's usually the component or the pads that get damaged. The solder joint itself, which is stronger than the capacitor or the pads, stays intact. It is not possible to solder the original part back, if its contacts are damaged. The contacts appear to be stuck to the original solder still on the pads.

    It is usually a bad idea, or even inpossible, to re-use SMT components, especially damaged ones, so a new capacitor will be required.
     
  13. jav6454 macrumors P6

    jav6454

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    #13
    Exactly. Which is why I recommend either going to Apple or getting a new capacitor and soldering it back in.
     
  14. Arta0613 thread starter macrumors newbie

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    Sep 9, 2013
    #14
    No warranty on my laptop.

    So how can a get a single capacitor? Searching for them yields me results to either get a new logic board or buy a used one from eBay and use a capacitor from that. Are either of these the steps to take?
     
  15. laurihoefs, Sep 11, 2013
    Last edited: Sep 11, 2013

    laurihoefs macrumors 6502a

    laurihoefs

    Joined:
    Mar 1, 2013
    #15
    If you plan on bringing the laptop to a repair shop, you don't need to search for the capacitor yourself. They will have suitable parts at hand.

    It might be useful to know the exact capacitance of the original part. You might want to take a look at this thread: http://forums.macrumors.com/showthread.php?t=972699&highlight=no+backlight

    Search the linked thread with your laptops model number and with your logic boards part number. Hopefully you will find a schematic, that would tell the exact value. If you can't find the schematic, the thread starter Dadioh might be able to help you locate it.

    If you plan on doing the repair yourself, knowing the exact type, value and packaging will help you source the part. Getting a single SMT capacitor might prove tricky though, these are very cheap parts that are usually sold on reels that hold thousands of components ;)




    Edit: I tried searching the thread, no luck. Maybe you can ask if someone there could attach the page of the schematics where the Lattice LXP2 and related components are shown? Your logic board type should be 820-2915-b (I'm not 100% sure, check the labels on your actual board!).

    Finding the schematic is not absolutely necessary though, the repair shops should be able to measure the old capacitor and figure out the component they should use.
     
  16. jav6454 macrumors P6

    jav6454

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    #16
    A repair shop should have the capacitor (assuming they have the schematics on hand with the correct F rating).
     
  17. jezzy macrumors member

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    Montreal, Quebec
    #17
    oh just so what ive done in the past on other electronic equipment... solder in a piece of wire to bridge the pads :) and it did work..

    btw im no expert ! :)
     
  18. Macman45 macrumors demi-god

    Macman45

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    Somewhere Back In The Long Ago
    #18
    OP:

    Even though you have no warranty remaining, Apple want to know when things "Fall Off" I'd let them take a look at it...You may get it replaced for free...trying to solder that back is not as easy a job as it may appear.
     
  19. Astroboy907 macrumors 65816

    Astroboy907

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    #19
    Don't do this. Components are put there for a reason, shorting the pads could lead to even worse problems.
     
  20. Mr. Retrofire macrumors 601

    Mr. Retrofire

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    #20
    The CPU?

    ;)
     
  21. laurihoefs, Sep 12, 2013
    Last edited: Sep 12, 2013

    laurihoefs macrumors 6502a

    laurihoefs

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    #21
    I'm quessing it wasn't the CPU.. The OP said the computer was functional and ran normally, and I'm not sure, but I've been told that for a computer to function a CPU is required.

    ;)


    Seriously though, Arta0613, take the computer to a repair shop, they'll figure out the needed part and solder it in place. The soldering is a five minute job. A schematic would be a nice bonus, but it's not absolutely required, especially if you still have the original part.

    Or pop by an Apple Store and show it to a Genius, there's nothing to loose by doing so.

    Hope you get the laptop up and working quickly :)
     

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