Lenovo (GS44D/GS54D NM-C711 Rev:1.0) Motherboard not working

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  • BlackH
    New Member
    • May 2022
    • 8
    • Palestine
    #1

    Lenovo (GS44D/GS54D NM-C711 Rev:1.0) Motherboard not working

    hello friends..
    DC Jack is ok.. 20V entering the first MOSFET,, but nothing out..

    using my power jack to inject 20V after the first MOSFET, nothing out.
    but after inject 20V after the second FOSFET, the board worked,,

    when i remove the first MOSFET,, and inject 20V at the input of second MOSFET, the board worked,,
    try to change the first MOSFET,, but nothing changed.
    so i try to jumber the first MOSFET,, all things worked .. but the board can't charge the battery.
    i test the battery,, and its working very good..

    any suggestions?
    thank you
    Tags: None
    • FriedFred
      Senior Member
      • May 2024
      • 137
      • Germany
      #2
      What is the GATE voltage at those MOSFETs? Needs to be about 25V or so.

        Comment

        • mcplslg123
          Badcaps Legend
          • Jun 2015
          • 7262
          • india
          #3
          Jumpering a dc-in mosfet will always disable charging and may show short circuit when both adapter+battery is plugged in together. So not advised to do so.

          The mosfet is disabled for reason.

          Measure resistance between

          01. Source-Drain
          02.Source to Gate
          03.Gate to drain

          of 2 dc0in mosfets with no power attached. meter should be in atleast 200K or higher scale.

          Which charging IC is used?

            Comment

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