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A2337 new M1 MacBook Air problem Logic Board related, no video backlight 820-02016

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    Review the first pic in post #80 of this thread.

    Move the red meter probe to the other side of the caps. What is the resistance?

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      Originally posted by mon2 View Post
      Review the first pic in post #80 of this thread.

      Move the red meter probe to the other side of the caps. What is the resistance?
      I hope the pictures show everything well enough. Flipping the side and measuring there gives the exact same values.

      Attached Files

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        Can you share the pic for the CP600 block of parts?

        Click image for larger version

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        Comment


          Originally posted by mon2 View Post
          Can you share the pic for the CP600 block of parts?

          Click image for larger version

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          I should have included more info, it is already part of the ones I already uploaded. They are at the top.

          Attached Files

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            Do you have another idea / anything I could try or check or is it time to assume the board is internally shorted?

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              Originally posted by corintosh View Post
              Do you have another idea / anything I could try or check or is it time to assume the board is internally shorted?
              There's more caps off to the side of the screen connector and near the main storage caps that you've already removed.

              Do you have the boardview & schematic and a boardviewing program? This is FlexBV5 ( https://pldaniels.com/flexbv5 ) which has a free edition which may help you out here.

              Click image for larger version

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              Click image for larger version

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              YouTube Repair Videos - https://www.youtube.com/user/19PLD73
              FlexBV BoardView software - Linux/OSX/Windows - http://pldaniels.com/flexbv

              Comment


                Originally posted by inflex View Post

                There's more caps off to the side of the screen connector and near the main storage caps that you've already removed.

                Do you have the boardview & schematic and a boardviewing program? This is FlexBV5 ( https://pldaniels.com/flexbv5 ) which has a free edition which may help you out here.

                Click image for larger version

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                Click image for larger version

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                Thanks, I do already use flex and the schematic for my board. I removed all caps that flex showed to be part of the lcd backlight out. This includes the ones next to the screen connector and the 4 on each side next to the main storage caps.

                I included photos of the board with the caps taken off of all the regions.

                If it is time to stop trying other things I will likely sell it for parts. I don‘t think it is worth to buy a replacement logic board as I probably would have to replace married parts.

                Comment


                  Right, sorry about that one - I misinterpreted your pictures where you had the LCD connector + removed caps next to them in the next picture, definitely my bad there.

                  Did you also remove RP831 ? It's a resistor that takes the voltage back across XWP801 (internal link) to the controller. If you remove that and the short remains, then I'd say you've got a bad board likely. If the short disappears then look at the FB line parts and the controller

                  Click image for larger version

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                  YouTube Repair Videos - https://www.youtube.com/user/19PLD73
                  FlexBV BoardView software - Linux/OSX/Windows - http://pldaniels.com/flexbv

                  Comment


                    Originally posted by corintosh View Post

                    Thanks, I do already use flex and the schematic for my board. I removed all caps that flex showed to be part of the lcd backlight out. This includes the ones next to the screen connector and the 4 on each side next to the main storage caps.

                    I included photos of the board with the caps taken off of all the regions.

                    If it is time to stop trying other things I will likely sell it for parts. I don‘t think it is worth to buy a replacement logic board as I probably would have to replace married parts.

                    I just realised, YES, you already have removed those parts

                    Try remove the controller, just for the hell of it too.
                    YouTube Repair Videos - https://www.youtube.com/user/19PLD73
                    FlexBV BoardView software - Linux/OSX/Windows - http://pldaniels.com/flexbv

                    Comment


                      Originally posted by inflex View Post


                      I just realised, YES, you already have removed those parts

                      Try remove the controller, just for the hell of it too.
                      Thanks for staying on it with me!
                      The controller would be UP800? I will try it. I am still quite sure that when injecting voltage the very first time (still with RP831 on) it created a mark on it. Refering to post 76 in this thread.

                      Comment


                        Originally posted by corintosh View Post

                        Thanks for staying on it with me!
                        The controller would be UP800? I will try it. I am still quite sure that when injecting voltage the very first time (still with RP831 on) it created a mark on it. Refering to post 76 in this thread.
                        Correct, yes UP800. Normally I'm not one to subscribe to the notion of pulling chips without first determining a viable cause to blame them but sometimes after all this sort of work you end up just throwing caution in to the air and trying. At least it's a comparatively simple chip. Other possibility of course is the display connector itself.
                        YouTube Repair Videos - https://www.youtube.com/user/19PLD73
                        FlexBV BoardView software - Linux/OSX/Windows - http://pldaniels.com/flexbv

                        Comment


                          Originally posted by inflex View Post

                          Correct, yes UP800. Normally I'm not one to subscribe to the notion of pulling chips without first determining a viable cause to blame them but sometimes after all this sort of work you end up just throwing caution in to the air and trying. At least it's a comparatively simple chip. Other possibility of course is the display connector itself.
                          Alright I will give it a try. I am trying to learn as much as possible - could you explain your thought process behind this? I would have guessed the chip was out of the equation since we removed the path to it when RP831 was removed.

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