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MBP Mid-2012 Missing Question-Mark Folder

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    MBP Mid-2012 Missing Question-Mark Folder

    The MB chimes and has a working screen which illuminates as normal.
    I've followed the guides on SMC / PRAM resetting.
    I've removed the HHD and reset everything again, still no luck.
    I've tried to re-install Mac OS using a USB stick, again no joy.
    Nothing seems to recognised when using usb, although they do flash when plugged in.

    What should I try/do next.
    Any help is greatly appreciated.

    #2
    Re: MBP Mid-2012 Missing Question-Mark Folder

    Boot into Internet Recovery, erase the drive with Disk Utility and reinstall macOS.
    OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

    Comment


      #3
      Re: MBP Mid-2012 Missing Question-Mark Folder

      Followed your instructons, initially I had no joy, although the screen did dim momenterally after a few seconds but nothing happed.
      So I tried again with a second display connected through the displayport and hey presto I got an image, the MB screen is still white.
      I turned the MB off insterted a HDD with Lion already installed and checked specs, sys info etc.
      1. When opening window about this mac it only states it's a Macbook Pro nothing about size or screen. I've included an image(1).
      2. Changing the resolution worked fine but the display tab on about this mac states it's a 17 inch. I've included an image(2).

      My MBP is a 13-Inch Mid 2012 Core-i5-3210M.

      Thanks again.
      Attached Files

      Comment


        #4
        Re: MBP Mid-2012 Missing Question-Mark Folder

        I interpreted your issue as operating system not found. You mentioned the screen to be working, not showing a solid white background.
        If there is an issue related to LCD, first thing would be to try a known good LCD.
        OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

        Comment


          #5
          Re: MBP Mid-2012 Missing Question-Mark Folder

          Did you check the lcd connector on the board and the lcd cable? When you say working screen is it a known working screen or are you going by the fact it illuminates? If its the latter then try a known working screen.

          Comment


            #6
            Re: MBP Mid-2012 Missing Question-Mark Folder

            I've disconected the screen and connected to a MBP mid-2011 where it works fine, I can see the OS on screen.
            So atleast we know the screen is fine.
            The LVDS connector looks fine on the MBP, but I've included an image.

            I guess it's a case of fault finding along the gpu to screen output? or am going in a totally wrong direction.

            Thanks again for the help.
            Attached Files

            Comment


              #7
              Re: MBP Mid-2012 Missing Question-Mark Folder

              It's a 13" so GPU is indide CPU. Check voltage on pins 2/3 of J9000 and all pins of U9000
              OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

              Comment


                #8
                Re: MBP Mid-2012 Missing Question-Mark Folder

                Can you check diode mode on all 6 LVDS lines (pins 8-18) and voltage on pin 3 on J9000 (lcd connector) ?Is the board number 820-3115?
                Last edited by luckydip; 05-16-2020, 05:56 AM.

                Comment


                  #9
                  Re: MBP Mid-2012 Missing Question-Mark Folder

                  J9000:
                  Pin 1 0.26v
                  Pin 2 0.26v

                  U9000:
                  Pin 1 3.3v
                  Pin 2 0.24v
                  Pin 3 0.24v
                  Pin 4 0.26v
                  Pin 5 0.26v
                  Pin 6 Gnd

                  6 LVDS lines gave no shorts, with the following readings:
                  8 1768 ohms
                  9 1982 ohms

                  11 1758 ohms
                  12 1963 ohms

                  14 1746 ohms
                  15 1994 ohms

                  17 1839 ohms
                  18 1903 ohms

                  The board is 820-3115-B.
                  Thanks again for all the help.

                  Comment


                    #10
                    Re: MBP Mid-2012 Missing Question-Mark Folder

                    voltage on pin 3 on J9000

                    Comment


                      #11
                      Re: MBP Mid-2012 Missing Question-Mark Folder

                      U9000 pins 2/3 should have 3.3V, they are connected to PP3V3_S5 which must be present if the machine turns on. There is probably a break in the line.
                      OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                      Comment


                        #12
                        Re: MBP Mid-2012 Missing Question-Mark Folder

                        J9000

                        pin2 0.26v
                        pin3 0.26v


                        Miss labelled the pins sorry

                        Comment


                          #13
                          Re: MBP Mid-2012 Missing Question-Mark Folder

                          If I solder two small wires from Pin1 of C9009 to pins 2/3 on the U9000, this would fix the issue?

                          Comment


                            #14
                            Re: MBP Mid-2012 Missing Question-Mark Folder

                            Originally posted by Mechanicalbytes View Post
                            If I solder two small wires from Pin1 of C9009 to pins 2/3 on the U9000, this would fix the issue?
                            If there is voltage on c9009 pin 1 then yes otherwise you'll need to go further back

                            Comment


                              #15
                              Re: MBP Mid-2012 Missing Question-Mark Folder

                              Thankyou Piernov and Luckdip for all the help.

                              Soldered the wires as mention earlier and this solved the problem. My question mark folder has now been found.

                              Comment

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