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    Apple macbook pro A1398 not posting?

    Hi friends
    I have a macbook pro mid 2015. A1398.
    The laptop powers on but nothing on screen. And no "Chime" sound as well.

    I have checked all the rails and all provides related voltages.

    The black thin nylon cover on the PCH chip have sings of high temprature (some bubbles) and i noticed similar signs on the black paste rounding the vcore rails.

    When powers on, all the voltages are pressent. The fan is idle even when the cpu starts to wam up. And the pch also starts to raise its temprature .

    I do not know what to start with. As i suspect cpu or the pch chip.

    Any advise?

    Thanks

    #2
    Re: Apple macbook pro A1398 not posting?

    History of the machine? Exact voltage on CPU VCore?
    Post pictures around PCH and CPU
    OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

    Comment


      #3
      Re: Apple macbook pro A1398 not posting?

      Try resetting SMC and check if there is image via HDMI/external

      Comment


        #4
        Re: Apple macbook pro A1398 not posting?

        Originally posted by piernov View Post
        History of the machine? Exact voltage on CPU VCore?
        Post pictures around PCH and CPU
        My apologies for the late reply due to unexpected event.

        Thanks for following up.
        Unfortunately, i do not know the history of this laptop. But there is no water damage to the board. The only thing i noticed was the heating signs as i mentioned before.

        I have taken all the voltages of all the rails on the board.. and also took pictures for the pch showibg the sings of heating.


        Kindly refer to the attached photos.
        Attached Files

        Comment


          #5
          Re: Apple macbook pro A1398 not posting?

          Originally posted by luckydip View Post
          Try resetting SMC and check if there is image via HDMI/external
          Hi
          Sorry for being laye to reply.
          Yes i tried it. Same issue...


          Thanks for the advice

          Comment


            #6
            Re: Apple macbook pro A1398 not posting?

            Update::

            At some point without touch to replacing anything. Without attaching the power cord. I pressed the power button and got "charge the battery" indication on screen. Then tuned off. I tried to power it on again but the indication never come on again. Just black screen.
            Today at on the morning i powered it on without the power cord and the same indication appeared one more time. But now i am trying to power on (still without the power cord) but only black screen. No indications.

            Comment


              #7
              Re: Apple macbook pro A1398 not posting?

              Any help?

              Comment


                #8
                Re: Apple macbook pro A1398 not posting?

                connect lcd.... and measure if there is the right voltage on lcd to power it on. macbook air chime after a while, and sometimes didnt even chime because are in a sleep -fast boot mode. check with a lamp if backlight is broken.

                Comment


                  #9
                  Re: Apple macbook pro A1398 not posting?

                  Originally posted by dellxps15 View Post
                  connect lcd.... and measure if there is the right voltage on lcd to power it on. macbook air chime after a while, and sometimes didnt even chime because are in a sleep -fast boot mode. check with a lamp if backlight is broken.
                  As i mentioned, there were occasions where the laptop posted so the backlight and screen seems ok.
                  But i am not sure about the sleep status! Do you think the laptop will get hot in sleep mode? As the laptop always get power but only occasionally post. Also the heatsink gets very hot but the fans are idle. The pch chip also raise temp gradually until gets very hot.

                  Comment


                    #10
                    Re: Apple macbook pro A1398 not posting?

                    taht high temperature make me thing about some bad chip like pch, absorbing too much power.board model name ? look for it and google if there is some common problem maybe with some capacitor.

                    Comment


                      #11
                      Re: Apple macbook pro A1398 not posting?

                      Board is 820-00163 (or 820-00426, same thing), no known issue except CPU VCore VRM chip that can cause random shutdown occasionally (but not really common on this model).
                      Plug in USB drive and check if the activity LED blinks after a while. If nothing I'd try a known good EFI just to exclude this possibility.
                      OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                      Comment


                        #12
                        Re: Apple macbook pro A1398 not posting?

                        Originally posted by dellxps15 View Post
                        taht high temperature make me thing about some bad chip like pch, absorbing too much power.board model name ? look for it and google if there is some common problem maybe with some capacitor.
                        Thanks for the reply.
                        The pch was my main suspect based on its physican condition... what was wiered is that it posted occasionally.. and also the strange fan that is only running in idle mode even when the cpu is horribly hot...

                        Comment


                          #13
                          Re: Apple macbook pro A1398 not posting?

                          Originally posted by piernov View Post
                          Board is 820-00163 (or 820-00426, same thing), no known issue except CPU VCore VRM chip that can cause random shutdown occasionally (but not really common on this model).
                          Plug in USB drive and check if the activity LED blinks after a while. If nothing I'd try a known good EFI just to exclude this possibility.
                          Thanks for the reply.
                          I will try it today and update the post.

                          The VRAM Chip! That sounds promising as i never checked it. Will see.

                          Comment


                            #14
                            Re: Apple macbook pro A1398 not posting?

                            It could be a corrupted EFI try find a good working dump EFI and reflash it.

                            Comment


                              #15
                              Re: Apple macbook pro A1398 not posting?

                              Originally posted by MobileXT View Post
                              It could be a corrupted EFI try find a good working dump EFI and reflash it.
                              Hi
                              Thanks for the reply.
                              I have tried a good Dump but same issue.
                              The cpu is getting very hot. Then the pch gradually build up heat and eventually gets hot.

                              With the word hot i mean the cpu get hot even when the fans are at full speed.

                              Comment


                                #16
                                Re: Apple macbook pro A1398 not posting?

                                Originally posted by piernov View Post
                                Board is 820-00163 (or 820-00426, same thing), no known issue except CPU VCore VRM chip that can cause random shutdown occasionally (but not really common on this model).
                                Plug in USB drive and check if the activity LED blinks after a while. If nothing I'd try a known good EFI just to exclude this possibility.
                                I managed to get a donor board. But i am not sure which one should i replace first the CPU or the PCH chip. My expectations are going toward the CPU though. As it is getting hot really fast. But I am open to your suggections...

                                Thanks in advance

                                Comment


                                  #17
                                  Re: Apple macbook pro A1398 not posting?

                                  Any success to repair this? Have same symptoms...

                                  Comment


                                    #18
                                    Re: Apple macbook pro A1398 not posting?

                                    Originally posted by AuroXad View Post
                                    Any success to repair this? Have same symptoms...
                                    I am intending to replace the pch chip but still did not find such free time to with ...

                                    Will let you know the process as soon as i replaced it.

                                    Comment


                                      #19
                                      Re: Apple macbook pro A1398 not posting?

                                      Okey, so I pushed forward with my problem. I found a SMC Bypass method where you have to disconnect battery and charger, then press and hold power button for 10sec and while holding plug in charger and still hold while systems starts. My computer started to chime and booted successfully, but there are other issues. You should try this method also

                                      Comment


                                        #20
                                        Re: Apple macbook pro A1398 not posting?

                                        Originally posted by AuroXad View Post
                                        Okey, so I pushed forward with my problem. I found a SMC Bypass method where you have to disconnect battery and charger, then press and hold power button for 10sec and while holding plug in charger and still hold while systems starts. My computer started to chime and booted successfully, but there are other issues. You should try this method also
                                        thanks for the update.
                                        I have already tried this but holding the pwr btn 10s and keep holding it while connecting the charger, it does noting. Even the charger led never turned on. Then keeping the charger connected and releasing the pwr btn kicks on the fans at highest speed and surprisingly no led indications on charging tip.

                                        However, with just connecting the charger, the led comes on and the fans build up speed gradually.

                                        Both scinarios no post.
                                        Last edited by Weelcup; 08-20-2020, 05:37 PM.

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