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820-3332-A Macbook Pro Retina 15" Shorted on PPBUS_G3H

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  • 820-3332-A Macbook Pro Retina 15" Shorted on PPBUS_G3H

    Hi, have a customers Macbook pro retina 15" 820-3332-A
    1. I have pp3v42(green and yellow light) on the charger.
    2. No water damage, computer just shut off for customer
    3. L7030 > Pin 2 outputs 1.5v.
    4. R7020 pin2 only 16.5v.
    5. U7000 pin3(AC IN 3.8v)

    update: it seems u7000 is shorted. The IC its burning hot. So it must be a short on the IC, or could it be something else shorting it to ground?

    Any suggestions pls? thanks
    Last edited by patrickribbsaeter; 03-05-2019, 02:38 PM.

  • #2
    Remove U7000 and see if the short goes away.

    Comment


    • #3
      "R7020 pin2 only 16.5v."
      No voltage on pin2???
      That means burnt resistor; never saw this...
      Check for short C7021/22 and pin 28/ISL6259.
      Also one of C7030-36 can be shorted...

      Comment


      • #4
        1. I changed the U7000 and I got the green/orange light back. Might have been a bad u7000. Because it was working when i started troubleshoot.
        2. Still NO fan spin though.

        Ok, i will check what 2informaticos said above. and give you update on that
        Last edited by patrickribbsaeter; 03-05-2019, 05:31 PM.

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        • #5
          "R7020 pin2 only 16.5v."
          Pin2 now suddenly 194.6 millivolt. this happened now after i changed the u7000. before it was 16.5v. (I like to point out i took the U7000 from a donor board) Im waiting for new IC's & parts to come in. Could that be the problem.

          No voltage on pin2???
          only 194.6 millivolt.

          That means burnt resistor; never saw this...
          There are more places now on PPBUS_G3H line which is not showing correct reading. Its like te voltage is confused and cant zone in on a reading. I continue the trouleshoot the parts not showing correct voltage and post them here.

          Check for short C7021/22 and pin 28/ISL6259.
          pin 28/ISL6259 Showing 228 millivolt. same thign there, DMM cant read properly. and C7021/22 same thing.

          Also one of C7030-36 can be shorted...
          Same thing, the volt fluctuates same as i stated above. Strange! I will try to reflow the u7000 and see if that improves the Voltage ralls.

          Will do some more troubleshooting and give u update asap.
          Last edited by patrickribbsaeter; 03-05-2019, 06:09 PM.

          Comment


          • #6
            "No voltage on pin2???"
            Mea culpa, read it as "No voltage on pin1???"

            I asked to check for short on several points.
            That means diode mode (red probe to ground), NOT voltage...

            Comment


            • #7
              C7021 = 0.520 (Diode mode)
              C7022 = 0.525 (diode mode)
              ISL6259 pin28 = 0.525 (diode mode)
              C7030 = 0.513 (diode mode)
              C7036 = 0.516 (diode mode)
              R7020 (pin 2, im ttaking diode mode from testpoint which is connected to R702 pin2) I get 0.518 (diodemode)

              I still have green/orange light, but no fan spin..

              What should I check next?
              Last edited by patrickribbsaeter; 03-11-2019, 03:12 AM.

              Comment


              • #8
                What voltage you get on Q7030 (pin 5) and L7030?
                Post resistance to ground on L7030 too.

                Comment


                • #9
                  Q7030 (pin 5) = 16,1v
                  L7030 = 290.4mv on both pins
                  resistance to ground on L7030(pin1) = 50 ohm

                  The transistor Q7030 is super hot, burning hot so 100% its shorted. Im going to change it and let u know..
                  Last edited by patrickribbsaeter; 03-11-2019, 06:00 AM.

                  Comment


                  • #10
                    Q7030 is not shorted; you get different input/output voltages!!!

                    Remove F7040/41 and check which side remains the low value (50 ohms) to ground.

                    Comment


                    • #11
                      I was a bit to quick. I removed the Q7030, added another Q7030 from another board. but not I put back the first Q7030.. and suddenly the L7770 is getting super hot.. I might have screwed it up more by removing and putting back the Q7030.. problem now is the COIL (L7770)

                      Comment


                      • #12
                        Now the board only draw 0.020 Amp.. from dc supply...

                        Comment


                        • #13
                          fi i keep DC supply on for a while, now something else shorts.. The crystal shorts now... But not the coil anymore.. Why's that?

                          Q7080 is getting hot now. only this one.
                          Last edited by patrickribbsaeter; 03-11-2019, 08:06 AM.

                          Comment


                          • #14
                            Seems that you don't want to follow our advices
                            We cannot help in this way!

                            "Remove F7040/41 and check which side remains the low value (50 ohms) to ground."
                            Be sure to solder Q7030 properly...

                            Comment


                            • #15
                              Sorry, I was just going a little bit to fast ahead. Wont do that again.. Just want to get this board fix.. guess my teqhnique will improve. So lets do this step by step!

                              Which is the correct way to measure Resistance to ground on the coil L7030?
                              Because i get two different readings when connecting the Black probe to ground compare to Red probe on ground.

                              thanks

                              Comment

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