N551JM - cold CPU , CPU vcore present

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  • magneh
    Badcaps Veteran
    • Apr 2014
    • 585
    • Portugal

    #1

    N551JM - cold CPU , CPU vcore present

    Hi!

    ive been trying to figure out this Asus N551JM mobo problem.

    The motherboard turns on by herself when I supply 19V with PS.
    Goes directly to 390 mA , and rises a bit to 410 mA 1 min after or so.

    All VCC signals are present, CPU vcore 1.7V etc
    NVidia GPU warms up, but what surprises me is that the CPU does not get hot at all. The 3 coils of CPU VCC are warm, but not CPU.

    Measured a bit and taking a look at the repair guide I came to the signal H_CPUPWRGD who is 1.07V
    I was expecting a signal around 3V, but not sure.
    This signal comes from the PCH.

    While measuring the board shut down itself (I assume) and consumption went down to 67mA(maybe due to Nvidia chip getting too hot without the cooler) . Found out the 3.3V/5V IC controller getting quite hot.

    Left a board for a minute, supplied power and back to the same 390mA (and 3.3V/5V IC working fine)

    this could indicate bad PCH?
    Or just a waste of time and leave it for donor board?

    Thanks for any advice
    Attached Files
  • piernov
    Super Moderator
    • Jan 2016
    • 4435
    • France

    #2
    Re: N551JM - cold CPU , CPU vcore present

    History of the machine?
    H_CPUPWRGD is ok. Check BUF_PLT_RST#. If present, try to flash the BIOS.
    OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

    Comment

    • magneh
      Badcaps Veteran
      • Apr 2014
      • 585
      • Portugal

      #3
      Re: N551JM - cold CPU , CPU vcore present

      Originally posted by piernov
      History of the machine?
      H_CPUPWRGD is ok. Check BUF_PLT_RST#. If present, try to flash the BIOS.
      Salut Piernov!

      Merci!

      Ive checked and indeed BUF_PLT_RST is 0.00V. Diode mode 0.5V to gnd.

      Going to flash the bios and see if something changes.

      Comment

      • magneh
        Badcaps Veteran
        • Apr 2014
        • 585
        • Portugal

        #4
        Re: N551JM - cold CPU , CPU vcore present

        Just flashed the bios with a working dump for N551JM with N16P-GX-A2 Nvidia chip. and still the same.

        BUF_PLT_RST# 0 V

        cpu still cold
        Attached Files

        Comment

        • SMDFlea
          Super Moderator
          • Jan 2018
          • 20405
          • UK

          #5
          Re: N551JM - cold CPU , CPU vcore present

          Originally posted by magneh
          Just flashed the bios with a working dump for N551JM with N16P-GX-A2 Nvidia chip. and still the same.

          BUF_PLT_RST# 0 V

          cpu still cold
          There`s a few things wrong with that bios you tried,apart from the extra code as it was backed up as an OTP chip. The boot guard profile configuration is set to unknown ,it should be set to 0 - no FVME. The PCH strap 2 has MCTP as 0x2B it should be 0x00 . You need to try another bios with clean ME firmware.

          If you have your original bios backup post it in the Bios Requests section for the ME sorting .

          https://www.badcaps.net/forum/forumdisplay.php?f=40

          .
          Last edited by SMDFlea; 01-25-2020, 10:19 AM.
          All donations to badcaps are welcome, click on this link to donate. Thanks to all supporters

          Comment

          • magneh
            Badcaps Veteran
            • Apr 2014
            • 585
            • Portugal

            #6
            Re: N551JM - cold CPU , CPU vcore present

            Originally posted by SMDFlea
            There`s a few things wrong with that bios you tried,apart from the extra code as it was backed up as an OTP chip. The boot guard profile configuration is set to unknown ,it should be set to 0 - no FVME. The PCH strap 2 has MCTP as 0x2B it should be 0x00 . You need to try another bios with clean ME firmware.

            If you have your original bios backup post it in the Bios Requests section for the ME sorting .

            https://www.badcaps.net/forum/forumdisplay.php?f=40

            .
            Original dump uploaded in bios section
            Thank you for the feedback on this OTP file

            Comment

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