Y740 short through PCB, missing vccsa.

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  • RichieRyu123
    New Member
    • Feb 2022
    • 3
    • Indonesia

    #1

    Y740 short through PCB, missing vccsa.

    Hello recently my friend gifted me a broken Lenovo legion y740, with the board number of LA-G132P. it seems there's a big old explosion in the vccsa part, which left a hole through the board. removing the short proved to be kinda dificult and left a pretty sizeable hole in the board. i have seen the schematic from the y750(LA-J561P) which have similar or probably the same vccsa circuit. the problem is while grinding the board im not quite sure which component( resistor and capacitor) that i have removed and which one i need for rebuilding the circuit. does anyone have the photo of the front and back of the board? in the area near the cpu.

    thanks, -Ryu
  • Sephir0th
    Badcaps Legend
    • Oct 2020
    • 1262
    • Germany

    #2
    Re: Y740 short through PCB, missing vccsa.

    This wouldn't even cover the inner layers. A picture of how it actually looks like would be helpful.

    And is the VRM circuit even confirmed good at least from resistance measurements? Usually a CPU wouldn't survive a big damage near the VRM.
    FairRepair on YouTube

    Comment

    • RichieRyu123
      New Member
      • Feb 2022
      • 3
      • Indonesia

      #3
      Re: Y740 short through PCB, missing vccsa.



      im not sure if the the vcore is good but the resistance is around ~1.5 ohm, and vccio is still present but neither gpu nor cpu is powering on because vccsa is missing.

      Comment

      • sect-sin
        Senior Member
        • May 2022
        • 101
        • Hungary

        #4
        Re: Y740 short through PCB, missing vccsa.

        RichieRyu123,

        I have the same board here. My issues are different - keyboard lights up, fan spin, but no image and no post. It is not the BIOS, I reprogrammed it, but it does not help, so I am still hunting for my fault. I hope it is not the EC, as I do not have an EC programmer.

        Anyway, if you post a picture of your hole and its area to pinpoint where it is, I can help you with images of a good board.

        Cheers,

        sect-sin

        Comment

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