dv7-4171eo and dv 2000 high voltage after mosfet

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  • openminded
    Senior Member
    • Apr 2017
    • 73
    • home
    #1

    dv7-4171eo and dv 2000 high voltage after mosfet

    Hi,

    I have a dv7-4171eo that behaves as followed:
    - powers on, lights light up
    - fan spins shortly
    - screen remains black

    The laptop gets hot near the bridge chip and mosfets on two sides that have 19v in output a high voltage on the other side if the power is on. that voltage also fluctuates highly, between 50 and sometimes over 1000v!

    The dv2000 behaves very similar, but voltages are between 50 and 200v.
    I thought there should not be a higher voltage then the charger voltage, does anyone know what causes this?
    I cannot find anything burnt or otherwise strange.
    The dv7-4171eo has a ATI graphics chip, the dv2000 Nvidia.

    Given the measurement I thought there may be a common fault, but I couldn't find anyone else having it.
    Happens with different chargers too, original HP.

    Any tips are greatly appreciated!
    Tags: None
    • piernov
      Super Moderator
      • Jan 2016
      • 4435
      • France
      #2
      Re: dv7-4171eo and dv 2000 high voltage after mosfet

      There's surely an issue with the measurements.
      Doesn't really matter anyway, the dv7-4171eo will have a dead RS880M.

      dv2000 isn't the full model number so can't say anything about it.
      OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

        Comment

        • openminded
          Senior Member
          • Apr 2017
          • 73
          • home
          #3
          Re: dv7-4171eo and dv 2000 high voltage after mosfet

          Originally posted by piernov
          There's surely an issue with the measurements.
          Doesn't really matter anyway, the dv7-4171eo will have a dead RS880M.

          dv2000 isn't the full model number so can't say anything about it.
          hi, thanks for the quick response.
          The meter seems quite decent and I measured multiple times, other voltages seem ok.
          RS880M is the Ati video chip, right? Any point in trying to change it?
          Might have been killed by reflow.

          The other one has model dv2140eu.
          Do you think that either are fixable with a heatgut and chip mold or not worth trying?
          Thanks!

            Comment

            • piernov
              Super Moderator
              • Jan 2016
              • 4435
              • France
              #4
              Re: dv7-4171eo and dv 2000 high voltage after mosfet

              dv2140eu will have a dead NVidia G6150. Both have to be replaced with new chips.
              OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                Comment

                • openminded
                  Senior Member
                  • Apr 2017
                  • 73
                  • home
                  #5
                  Re: dv7-4171eo and dv 2000 high voltage after mosfet

                  thanks for your quick response. mmm, that might not be worth the trouble then, they're quite old. I will give it some thought, I have a hot air with chip mold but not sure if I can fix that without frying them. cheers

                    Comment

                    • piernov
                      Super Moderator
                      • Jan 2016
                      • 4435
                      • France
                      #6
                      Re: dv7-4171eo and dv 2000 high voltage after mosfet

                      I have no idea what "chip mold" is, but to replace large BGAs you need a BGA rework station.
                      OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                        Comment

                        • openminded
                          Senior Member
                          • Apr 2017
                          • 73
                          • home
                          #7
                          Re: dv7-4171eo and dv 2000 high voltage after mosfet

                          hi, I mean the metal part that can go on a heat gun that fits over the chip.
                          I don't have reballing tools, so I guess it's too much of a hassle.
                          Thanks

                            Comment

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