Macbook A1278 logic board repair

Discussion in 'General Electronics Chat' started by rabbit121, Apr 8, 2014.

  1. rabbit121

    Thread Starter New Member

    Apr 8, 2014
    Hi guys, I'm looking for a little advice on repairing a macbook that somebody spilled liquid on. It's a mid 2012 Macbook pro 13.3" A1278 i5 2.5ghz. the board doesn't look too bad except around this component in the picture circled by red.

    At this point I will point out I don't know very much about electronic components, but I have had a little experience soldering and repairing/modifying electronics from Google and Youtube!

    From what I've gathered it's a 4.7uh surface mount inductor..? and it looks quite badly corroded and damaged from the sides. It tests ok for continuity but the resistance is measuring 0.7 ohms and from what I gather it should be more like 1-10 ohms otherwise it's probably shorted.?

    Is it worth a shot trying to fix it? is there a way to figure out what the exact specs of that inductor is so i can start looking for one?

    thanks for any advice!


  2. praondevou

    AAC Fanatic!

    Jul 9, 2011
    The inductor is most likely ok. Inductors can have a wide range of DC resistance depending on the length and gauge of the wire used. Forget about this.

    What does the board not do? Does it power on?

    First of all you could clean the area where liquid was spilled . You could use a little brush or similar and alcohol or flux remover. Then blow it dry with a hair dryer or similar. Wait a day or two , let it sit in a dry place.

    Then power it on and tell us until where you can measure the DC input voltage.
    Unless you are lucky you will need advanced skills to repair a main board. Plus some good soldering equipment.
  3. Zerotolerance


    Sep 18, 2011
    Without the proper equipment (IE - rework station, nice soldering iron, etc) you are best off buying a replacement board. I would first try what was suggested and clean it with some alcohol and a Q-Tip and then power it up and use a multimeter to test where DC power stops.

    Looks like a SMD diode/transistor and a capacitor/resistor to the right of the inductor as well. I would say those are probably shorted.
  4. rabbit121

    Thread Starter New Member

    Apr 8, 2014
    I'm getting nothing when the power button is pushed. no activity at all. when the magsafe is plugged in the light stays green even though the battery is dead.

    I'll try cleaning it a bit more more with some alcohol like suggested. then go from there.

    can't justify a replacement board, the going price is about $700 plus the battery is likely bad too. a few hundred more and I may as well buy a new one that didn't drink a glass of whiskey. :rolleyes:
  5. rabbit121

    Thread Starter New Member

    Apr 8, 2014
    Well!! I lightly cleaned the dirty spots with some alcohol and a Q-tip, slapped it together and heard signs of life! The optical drive tried to eject, and the fan powered up!

    No video and I couldn't make it do it again but that's still pretty promising!