Advanced logic board component level repair question.

Discussion in 'MacBook Pro' started by h4lp m3, Aug 1, 2013.

  1. h4lp m3 macrumors 6502

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    #1
    This may be an extremely long sho,t but I need help identifying the keyboard/trackpad IC chip controller on a 820-2101-A logic board.

    The power button works, but the keyboard and trackpad are both unresponsive. I bought a new topcase hoping it would solve this problem but it did not. :(
     
  2. Astroboy907 macrumors 65816

    Astroboy907

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    #2
    Check around the forum for a schematic of the specific macbook. It should be in the schematic unless it is a custom part. Also might be worth a shot to look at the ifixit teardown of the computer, they sometimes identify the chips for trackpad control. You prepared to do some hot air rework?
     
  3. jav6454 macrumors P6

    jav6454

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    #3
    Why not go to ifixit? They have the correct parts and tools for your current problem.
     
  4. Astroboy907 macrumors 65816

    Astroboy907

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    #4
    I find ifixit to be more concerned with replacement parts (cables, screen, etc) then replacing a chip directly on the logic board. Most at ifixit would rather just get a new LB. This guy means to do some serious repairing on his computer...
     
  5. h4lp m3 thread starter macrumors 6502

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    #5
    Thanks for the responses and I think I'm a little closer... I just need to determine if the keyboard/trackpad is controlled from within the Intel southbridge.
     
  6. jav6454 macrumors P6

    jav6454

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    #6
    Unless you have a reflow oven with you, I wouldn't recommend doing manual soldering.
     
  7. h4lp m3 thread starter macrumors 6502

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    #7
    I do and it takes pictures. Can anyone identify these?
     

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  8. h4lp m3 thread starter macrumors 6502

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    #8
    And these.
     

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  9. gr8tfly, Aug 1, 2013
    Last edited: Aug 1, 2013

    gr8tfly macrumors 603

    gr8tfly

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    #9
    I hate to bring up iFixit again, but check with them and see if they did a tear-down of your particular model. They usually will identify major components when they get to the individual boards.

    Otherwise, I don't think you'll find any schematics for the logic board. The most you'll find is a functional block diagram, which might answer your SouthBridge question (I might have the diagram, but need to know the specific model MBP. Looks like those chips are from 2007, so I probably can find the diagram.).

    Try searching (Google, whatever) the component name - I just did that with the TPS51116, and it's a DC-DC regulated power supply (http://www.ti.com/product/tps51116).
     
  10. Astroboy907 macrumors 65816

    Astroboy907

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    #10
    I actually have a full schematic for my MacBook Pro (nets, busses, chips, right down to individual resistors)... They exist, you just have to search for em (a lot) :)

    To OP, there is a thread here titled "No backlight - logic board question?" Or something like that (it gets posted to pretty often). I found the schematic (and actually a circuit board layout) over there. I bet you'll find something over there. As for the chips I'm not very good at identifying but ill give it a shot and let you know if I find anything!
     
  11. h4lp m3 thread starter macrumors 6502

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    #11
    It's an A1226 with a 2.6GHz 820-2101-A logic board. Thanks :)
     
  12. nickandre21 macrumors 6502a

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    #12
    there is a chip that is usually above if not near the keyboard ribbon connector. It controls the usb hub of the trackpad n keyboard.
     
  13. gr8tfly macrumors 603

    gr8tfly

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    #13
    Keyboard and trackpad are controlled via a USB 2 port from the South Bridge.

    ----------

    This.

    Usually, related components are near the cable going to the device (kybd/trackpad, in this case).
     
  14. jav6454 macrumors P6

    jav6454

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    #14
    Where in the Greater New Orleans area would you have a Reflow Oven Access to? Not being sarcastic. I'm just curious. No, your kitchen oven doesn't count. Also, you need the correct Solder Paste quantity and Type. Not having either of those is one-way to causing shorts and damaging your board.

    Let's not forget about heat sensitive components which need to be soldered at a specific thermal profile and sometimes can only be reflow soldered once.

    Are you sure you wan to go through all that?

    More over, do you have enough precision to pick and place that component where it needs to go at the correct height, angle and polarity? Not to mention the correct pressure to place it in order to avoid solder paste shorts.
     
  15. Astroboy907 macrumors 65816

    Astroboy907

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    #15
    I think i found the schematic for your model. Go at your own risk- finding this stuff for free generally involves shady websites but I think this is fine...

    The "51117" chips seem to be voltage regulation/buck controllers
    It also seems to be a voltage reg on the schematic.

    The SLG2AP101 is a low power clock generator (schem. pg 5, part # 359S0130)

    ----------

    The ISL9504 say "SYNC REG CTRL" on the schematic (pg 5, part # 353S1461)
    It might also be a CPU current sense filter (appears on page 49)

    The TPS51116 is (probably) part of the DDR2 voltage supply (pg 62).

    Also you can find the number designations of the chips on the board and run those through a search of the schematic. Example being the ISL9504, the number by it is U7100. A schematic search for that number brings the part number and a page for the specific module that it is part of.
    Hope this helps!

    Edit: just checking, but are you sure it is the chip? Most likely it would appear blown and not just stop functioning, right? Perhaps it is a related component (fuse, resistor, etc). Might be worth checking the schematic for the keyboard controller and seeing what parts are used in its supply chain.
     
  16. Astroboy907 macrumors 65816

    Astroboy907

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    #16
    Any luck yet?
     
  17. Astroboy907 macrumors 65816

    Astroboy907

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    #17
    I really don't mean to bump as much as find out how this went. Did it go anywhere? Any luck finding the right parts? Still willing to offer up some help! :D
     

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