My experience with MacBookPro A1990 shorted

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  • alxtoulouse
    New Member
    • Jun 2020
    • 2
    • France

    #1

    My experience with MacBookPro A1990 shorted

    Hello,

    just want to share my experience with my macbook pro 15" that I bought in dec 2019.
    For a few months, the screen was not working (just black) without any reason (no spill, no stepped on it, nothing except covid ), it was working fine on an external display.
    I started to browse the web and found some «*flexgate*» posts so I tried this way: I started to cut the wrong flex, and as I had the naked board in front of me, I decided to check some caps (I am a beginner in electronics and micro soldering)
    I got continuity on all the caps of the LCD circuit, showing that the main power rail for the displays PPVOUT_S0_LCDBKLT was shorted to ground…
    I removed all caps one by one (C8460—>C8473, CC785—>CC788, CC70A), then a bunch of other components and also the diode isolating the LCD circuit (D8410) but still have the short. I even removed the connector J8500.
    In the meantime, I received a thermal camera I ordered and I used it with voltage injection and finally found the root cause: a short inside the board located under C8471 and C8472!
    I had nothing to lose so I digged at that location with surgical knifes and found some blackish residue indicating a short between 1st (GND) and 2nd layer (PPVOUT), I scrapped until I tested no short with the multimeter. I cleaned and I filled the hole with UV mask.
    I resoldered all components, the connector, still no short and now I have to remount everything (didn't find time yet). Hope the screen will work (I am afraid that the short has been caused by something bigger…)
    I posted 3 pictures of the «*hole*» and one of the board area where the short was.

    If anyone experienced that kind of issue, feel free to share.

    long life to this very useful forum!

    A1990 board 820-01814
    Attached Files
  • suli
    New Member
    • May 2023
    • 2
    • China

    #2
    Re: My experience with MacBookPro A1990 shorted

    Interesting journey.did you found the root cause?

    Comment

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