Macbook Pro 13 no function with Ram

Discussion in 'MacBook Pro' started by gerikerschi, Feb 24, 2015.

  1. gerikerschi macrumors newbie

    Joined:
    Jun 24, 2014
    #1
    Hi!

    I have a Macbook Pro 13 from 2010.
    Last week the macbook is fallen on the floor.
    Since this time it does not boot.
    I can turn on the Macbook, but after this no sound, no POS-Test and a black screen. The power led lights and the fan turns.
    Apple write, that a black screen with the power light on is a problem during the POST or boot ROM failure.
    When I remove both Ram, I hear one beep sound. With Ram no function.
    I also use other Ram to test the Macboot, but also the same problem.
    How can I find the root cause for this problem?

    BR
    Gerald
     
  2. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #2
    Sounds like the fall damaged the computer, perhaps the logic board or some other component. I don't think you can find the root of the failure.

    Take it to apple and see what they say and how much it will cost to repair.
     
  3. gerikerschi thread starter macrumors newbie

    Joined:
    Jun 24, 2014
    #3
    Thanks for the answere, but I wan't to repair the board by myself.
    I have the schematic and the board view of the A1278 2010 and a good one to check the voltages.
    I would like to understand where the problem is approximately on the logicboard.
    I am also sure, that this is a logicboard problem.

    BR
    Gerald
     
  4. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #4
    If that's the case, you need to check each component and see if the voltage readings are identical. I'm not sure how viable replacing surface mounted components are but good luck
     
  5. gerikerschi thread starter macrumors newbie

    Joined:
    Jun 24, 2014
    #5
    Problem found!

    Problem found without checking all components! ;)
    I measure all test points from the schematic and I found a problem by the U1400 graphic chip.
    No current on J9000 pin 2 and 3.
    The LCD_IG_PWR_EN signal is missing.
    So the graphic chip has an open contact.

    BR
    Gerald
     

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