lenovo 80nj motherboard short to ground

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  • garrymc123
    Badcaps Veteran
    • Apr 2010
    • 336
    • United Kingdom
    #1

    lenovo 80nj motherboard short to ground

    Hi Guys need some help please got this laptop to repair and it would not power up so i removed the mother board from the laptop and tried to power it up i noticed that pu401 3.3v power ic was getting hot so i removed it and also the output capacitor as it was short to ground thinking this was the fault but in further investigation i have more power supplies shorted to ground.I have attached some pics with the shorted to ground parts in red and the removed items in yellow any help to trouble shoot the motherboard would be much appreciated Thanks in advance .
    Attached Files
    Your never to old to learn
    Tags: None
    • ktmmotocross
      Boardkiller
      • Feb 2014
      • 3586
      • slovakia
      #2
      Re: lenovo 80nj motherboard short to ground

      u must locate shorts. wipe solder from PJs to locate on which side is short

        Comment

        • piernov
          Super Moderator
          • Jan 2016
          • 4435
          • France
          #3
          Re: lenovo 80nj motherboard short to ground

          Stuff near the CPU is most likely not shorted to ground. CPU Vcore line will have a very low resistance to ground, it's perfectly normal.
          OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

            Comment

            • ktmmotocross
              Boardkiller
              • Feb 2014
              • 3586
              • slovakia
              #4
              Re: lenovo 80nj motherboard short to ground

              short means resistance lower than 2-3ohm, higher is ok walue for high current ICs like CPU and GPU

                Comment

                • garrymc123
                  Badcaps Veteran
                  • Apr 2010
                  • 336
                  • United Kingdom
                  #5
                  Re: lenovo 80nj motherboard short to ground

                  ok thanks guys so that would explain why my output of 1.5v ics are showing up as connected to ground.
                  Your never to old to learn

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