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Macbook 820-00165-A no green, no fan

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    Macbook 820-00165-A no green, no fan

    Hi guys. I'm at a point where i actually logged in to ask for some guidance. This is one of my first repairs but i've gone through so much material during the last 3 months that my mind is just blowing up.

    I'm working on a 820-00165-a

    The macbook air had water damage - cleaned it and it booted everything seemed fine except for the fact that it didnt see the SSD. It had 3.3v on the rails and i checked the SSD in a external drive thingy on a different mac.

    I cleaned it manually - i dont have an ultrasonic sadly but the water damage wasn't severe - only a couple spots near the ssd

    during my blind search to find whats going on the board i must have shorted something because the board currently won't boot. When i connect the DC power supply at 14.7V it sits on 0.02A Amber light. No green, no fan spin.

    I'm measuring all the things that go to the onewire circuit on this board and on another (scrap but the onewire works with a fan spin) and can't find any irregularities. I'd gladly replace something but I simply don't know what to try
    since i don't know where to go with this i measured everything i could
    DC PS SET AT 14.7V
    Taking 0.02A

    PPBUS_G3H 8.5V
    PPBUS_S5_HS_COMPUTING_ISNS 8.5V
    PPDCIN_G3H_ISOL 18.5V
    PPDCIN_G3H 14.7V (18.5V)
    PP3V42_G3H 3.38V
    PPVRTC_G3H 3.28V (3V)
    PP5V_S5 4.97V
    PP5V_S4R3 0V - seems to be shorted
    PP5V_S0 0V - no short

    PP3V3_S5 - 3.28V
    PP3V3_S4 - 0.02V - same amount the PS is drawing. micro micro beep when checkin continuity
    PP3V3_S3 0V
    PP3V3_S0 0V
    PP3V3_S4SW_SNS 0V

    PP1V8_S3 0V
    PP1V2_S3 0V

    PP1V05_SUS 1.04V
    PP1V5_S0 0V

    PP0V6_S0_DDRVTT 0V
    PP1V05_S0 0V
    PP1V05_S0SW_PCH_HSIO 0V


    i'd be satisfied with just getting the macbook up to the green light/fan spin part. I think the SSD working will just be too much.

    I'd appreciate any HELP/GUIDANCE. I'm gonna be logged on all night trying to self-crack this

    #2
    Re: Macbook 820-00165-A no green, no fan

    Study the power rail order chart inside the schematic. It will start with the dcin plug as '1' and continue from there.

    Follow the ordering to locate a fault.

    Is the adapter the original?

    Comment


      #3
      Re: Macbook 820-00165-A no green, no fan

      i've tried to measure with original adapter and with a dc power supply with a original cable tip.

      Do you mean Power Aliases page ? Cause i put all the measurements from there in the post

      If u mean the page starting with J7000 then i've measured everything including u7090 and the measurements seem fine

      all resistors seem to have good resistance

      please ask for any specific part and i'll give every measurement possible

      Comment


        #4
        Re: Macbook 820-00165-A no green, no fan

        Voltage reading of PPVIN_G3H_P3V42G3H ?

        PP3V42_G3H 3.38V
        This rail is low. It should be 3v42. Power down and post the resistance to ground for L7095, pin #2.

        Also confirm the resistance of the voltage feedback resistors that dial up the required 3v42 voltage setting @ R7095 and R7096.

        https://www.logi.wiki/index.php/PP3V42_G3H

        You can find the normal voltage values for your logic board here:

        https://www.logi.wiki/index.php/Power_Rail_List

        As noted, 3v42 is required so something goofy is going on here.
        Attached Files
        Last edited by mon2; 12-01-2021, 09:21 PM.

        Comment


          #5
          Re: Macbook 820-00165-A no green, no fan

          L7095 pin#2 is 3.39

          R7095
          pin#1 3.39V
          pin #2 1.28V

          R7096
          pin#1 1.28V
          pin#2 GND

          from what i understand PP5V_S4RS3 is supposed to be 0V since the macbook isn't turning on right ?
          Last edited by maru00; 12-01-2021, 09:36 PM.

          Comment


            #6
            Re: Macbook 820-00165-A no green, no fan

            my PPDCIN_G3H is 14.7V - the chart says 18.5V. Does that depend on the voltage i set on the dcps ? it's currently set to 14.7V - should i crank it up to 18.5V ? the original charger says its 14.85V

            Comment


              #7
              Re: Macbook 820-00165-A no green, no fan

              another thing i noticed is that D7005 gets 18.5v and 8.5 and should be 18.50 but is 18.19. Is that a normal drop?

              Comment


                #8
                Re: Macbook 820-00165-A no green, no fan

                r7096 has 183K resistance. should be 200k.
                R7095 has 250k. should be 348k.

                could this be the issue? should i replace them ?

                Comment


                  #9
                  Re: Macbook 820-00165-A no green, no fan

                  my PPDCIN_G3H is 14.7V - the chart says 18.5V. Does that depend on the voltage i set on the dcps ? it's currently set to 14.7V - should i crank it up to 18.5V ? the original charger says its 14.85V
                  There are often errors in the schematics. As your PPBUS_G3H is ok, do not be concerned about PPDCIN_G3H @ 14v7. It is ok.

                  another thing i noticed is that D7005 gets 18.5v and 8.5 and should be 18.50 but is 18.19. Is that a normal drop?
                  Yes, the voltage drop is normal. The dual diodes are not perfect conductors. They will have a 0.4 to 0.6 volt forward voltage drop. The higher of the 2 input voltages will be selected and the output of the diode will be about 0.4 to 0.6 volts lower than the input. The datasheet for the component will offer the details of the exact value for the drop.
                  from what i understand PP5V_S4RS3 is supposed to be 0V since the macbook isn't turning on right ?
                  PP5V_S4RS3 should be 5v0. This rail is created by U7501.

                  Voltage @ P5VS4RS3_EN_R ?

                  This is the ENABLE signal for U7501 which creates the PP5V_S4RS3 rail.

                  Power down and check the resistance to ground of L7520, pin # 1. Checking for very low resistance which may indicate a shorted cap on this leg.

                  Comment


                    #10
                    Re: Macbook 820-00165-A no green, no fan

                    r7096 has 183K resistance. should be 200k.
                    R7095 has 250k. should be 348k.


                    Yes. While the resistors may have different readings while on the logic board, remove each resistor and measure again out of circuit.

                    If the values do not match the schematic, then yes, recommend to replace them.

                    You should have 3v42 on this rail. The rail is a low current one so it cannot support too much of a load. Respectively, a bad cap on the rail can cause it to droop. Start with your resistor review.

                    DO NOT POWER up without these resistors in place. Otherwise the regulator will spit out the wrong and possibly higher output voltage and kill everything downstream!!!

                    Comment


                      #11
                      Re: Macbook 820-00165-A no green, no fan

                      P5VS4RS3_EN_R - 0V

                      L7520 - 45k

                      to be clear i put the multimeter in 200k in resistance - put black probe on ground and red probe on pin#1 and waited til the number stabilised at 45.5

                      Comment


                        #12
                        Re: Macbook 820-00165-A no green, no fan

                        Your measurement method is correct. The resistance is fine and does not show any shorting caps on the rail.

                        The P5VS4RS3_EN_R signal is not correct. This logic level may be low due to various reasons but first work on the 3v42 rail being normal.

                        It is late here (and for you) - time for me to get my beauty rest. Will check back in the morning. There are some excellent posts on the A1466 repairs with Louis (videos and forum); @Piernov who is on this forum and also in Australia:

                        https://www.it-tech.com.au/mac-q-a/m...-up-sequences/

                        https://www.it-tech.com.au/mac-q-a/m...d-power-rails/

                        Review these in the meantime but as noted, the 3v42 could be a key rail to fix up first.

                        Comment


                          #13
                          Re: Macbook 820-00165-A no green, no fan

                          thank you for your help

                          Comment


                            #14
                            Re: Macbook 820-00165-A no green, no fan

                            I have another strange problem here, the macbook air working fine with battery, but everytime I connect the adaptor, the adaptor light won't come up and the macbook air always shutdown and restart again with the backlight of LCD is on for a second then just never come up again then but the macbook air turns on, I can see the picture just no light on adaptor and no backlight, once I disconnect the adaptor and pull battery from the logicboard and turn on again, it's working fine as long as no adaptor connected.

                            Anyone please help me.

                            thank you.

                            Comment


                              #15
                              Re: Macbook 820-00165-A no green, no fan

                              If you shorted something, first off check impedance to ground for PCH/CPU as you could be wasting your time. PCH should be around 180 ohms or so (L7630), CPU 10 ohms or higher depending on model of CPU (L7310/7320).

                              With Air boards, it's common to see the voltages pulse briefly then revert back to S5 state and you can waste a lot of time trying to understand why you aren't getting to S4. So check first to see what voltages you get up to CPU Vcore when you first switch on.

                              Comment


                                #16
                                Re: Macbook 820-00165-A no green, no fan

                                the macbook air runs fine on the battery only, so there is no problem with the CPU or or PCH. only thing when I plug it the adaptor, it does not light up and the backlight just off directly and when I unplug the adaptor' it runs fine again. I suspect something short on PP3v42_G3H which also have line with the backlight circuit.I just don't understand clearly about this 820-00165-A but it's easy with 82-3437-A (13-14 years)

                                Comment


                                  #17
                                  Re: Macbook 820-00165-A no green, no fan

                                  Originally posted by qtechnoz View Post
                                  the macbook air runs fine on the battery only, so there is no problem with the CPU or or PCH. only thing when I plug it the adaptor, it does not light up and the backlight just off directly and when I unplug the adaptor' it runs fine again. I suspect something short on PP3v42_G3H which also have line with the backlight circuit.I just don't understand clearly about this 820-00165-A but it's easy with 82-3437-A (13-14 years)
                                  I was referring to the OP actually, you've hijacked the thread. Start a new post for your issue, it only confuses things for everyone.

                                  Comment

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