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macbook A1708 820-00840-A

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    macbook A1708 820-00840-A

    HI. I need help with this board! 5v/0a stable. Replacing the u7000 did not change the situation. Before I move on to replacing the SD3215, maybe there are some tips on what to pay attention

    also need a diagram and boardview
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    What is the resistance to ground of PPBUS_G3H ? (no power to the board while testing in resistance mode - only power to the people!)


      all indicators on the coils are normal and there are no short circuits


        What is the voltage to ground for the following?



          I replaced the u7000 from the working board again and the results were the same


            3v4 is good.

            With no power, check the full path resistance of the current sense resistor on U7000 (ISL9239).


              all components have a good value within 0.425 to 0.547 in diode mode! Removing f7000 does not affect anything


                Sorry - should have been more specific.

                1) Diode mode testing will only confirm that the I/O pin on the IC is not damaged. Your readings are good to validate this status.

                2) We are after the full path resistance of the current sense circuit so you will need to be in resistance mode on your meter (lowest scale if manual version meter) -> one meter probe on one side of C7020 and other meter probe on other side of this capacitor.

                We are wanting to confirm the start to end resistance which must match the schematic values. This is for the charging circuit current sensing.

                Repeat the same style of testing with C7023 = current loop sensing for the INPUT of this critical power rail.

                PS: Should you not be sleeping?

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                Last edited by mon2; 05-10-2024, 07:04 PM.


                  How are you measuring the current draw? Is it with a usb type C meter ?

                  Is the usb c meter a bidirectional type?

                  Since there are valid voltages on the board, the current draw should be > 0 A. Expecting at least a few mA on the current draw.


                    mon2 you should work as a consultant on the Rossman forum, otherwise they have a negative attitude towards inexperienced masters like me!
                    PS: Should you not be sleeping?
                    I have a lot of work that I'm new to


                      These are good measurements. Are you using a usb C meter? Is it bidirectional type ? Does the same tool show a valid current draw on other devices?


                        Originally posted by mon2 View Post
                        These are good measurements. Are you using a usb C meter? Is it bidirectional type ? Does the same tool show a valid current draw on other devices?
                        I made a video for you but I don't understand how it works here


                          Be sure that the USB C paddle board is firmly attached to the mezzanine connector. Even with a single LED as a load - there should be a current draw showing on the meter of a few mA.

                          The default power up voltage on the power adapter is 5 volts and with no load, it will be 0A for the current draw. Check the voltage on the input fuses on the board - do you see 5 volts?

                          Do test the same meter on another type C product to confirm the current draw feature is working.


                            The tester works flawlessly, checked!
                            I have no voltage on the F7000 (it is temporarily removed)


                              Check each of the LDO rails on the CD3215 ACE controllers - they must be present. Each CD3215 must be working to allow for the 20V power delivery contract as per the article by @Piernov.

                              CD3215 Bootup Sequence - LogiWiki

                              Confirm the voltage to ground of:


                              We must have a valid voltage on PPBUS_G3H to continue. Not shorted?

                              Confirm the DIODE mode readings for the _CC1 and _CC2 pins on each of the USB C port.

                              For example:


                              Last edited by mon2; 05-12-2024, 07:49 PM.


                                Now I will replace the CD 3215 with new ones and write down the results, do you ever sleep?)))) I sleep, you are here, I woke up, you are here))))


                                  I replaced it with new CD 3215, no changes.


                                  SMB_SMC_CHGR_SCL=2.6-3.4v unstable
                                  SMB_SMC_CHGR_SDA=2.6-3.4v unstable




                                      This is the CCx power rail for the BMC interface used by the power delivery communication. This power rail will only be active for the side of the USB-C blade that is being used to power the board. Confirm this by checking the LDO_BMC rail for the other side of the same USB-C connector that is being used. One side must offer this LDO rail with 1v1 output.


                                        I also changed the CD 3215 and still have PP1V1_UPC_XB_LDO_BMC = 0V (in diode mode 0.471)