thread top ad

Collapse

Announcement

Collapse
No announcement yet.

820-000165 wont turn on

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • 820-000165 wont turn on

    820-000165 with no liquid damage wont turn on. All power rails good up to P3V3S3 which is only 0.12V checked for shorts on both rails are not shorted. I see PM_SLP_S4_L is responsible for P3V3S3 I have 0V on PM_SLP_S4_L but no shorts on either rail.

    What to check next???

  • #2
    When checking pin 9 of U7100 noticed it was worked on before and was only getting 0.34V so changed ISL but in process the board made a snap noise and I now have a short on PPBUS_G3H. With all caps and ISL removed the short still remains. Is this a internal short at this point from using to much heat?

    Comment


    • #3
      Remove F7140 and see where the short remains.
      Which exact value (ohm scale) has that short?

      Comment


      • #4
        with F1740 starts at 0.10ohm and continuous climes to a higher number 1 by 1 every few seconds

        without 0.395

        checked everything with F7140 removed and short doesn't appear anywhere anymore. As soon as F1740 is back on o.10ohm and climbing returns. Tried different fuse but same result

        Comment


        • #5
          current voltage on PPBUS_G3H 0.272V

          Comment


          • #6
            If you really have short on PPBUS_G3H, it MUST be present in one pad of F7140, once removed...
            Disconnect charger and battery, when check diode mode, or ohm scale...

            Comment


            • #7
              0.90 with F7140 abnd 0.359 with removed.

              W

              Comment


              • #8
                0.90 with F7140 and 0.390 with it removed. Assuming I don't have a short at all now.

                What to check next? PPBUS_G3H only 0.272V already replaced ISL6259

                Comment


                • #9
                  F7140 has two pads.
                  So if removed, you MUST get two different readings; for each pad.
                  And you should get higher values without fuse; this depends by measuring pad too.

                  Comment


                  • #10
                    Are you measuring in diode mode or resistance mode? Try resistance to ground on pins 1 and 2 of the fuse

                    Comment


                    • #11
                      With F7140 pad 1 0.135 pad 2 0.135

                      Without F7140 pad 1 0.014 pad 2 0.420

                      diode mode

                      Comment


                      • #12
                        We asked resistance not diode mode. However, that is not good on pin 1 so you have a short on pin one side of PPBUS more than likely.

                        Comment


                        • #13
                          You do something wrong.
                          Cannot get lower reading without the fuse.
                          However, 135 (diode mode) is correct value.
                          No need to remove fuse then.
                          All I told to do is because you wrongly assumed a short there.

                          Be sure ISL6259 is properly soldered and post some voltages; 1, 2, 3, 9, 12, 13, 14, 17, 19, 20, 27.

                          Comment


                          • #14
                            Pin 1 17.19V

                            2 18.35V

                            3 0V

                            9 0.32V

                            12 3.442V

                            13 1.779V

                            14 0V

                            17 0.45v

                            19 5V

                            20 5v

                            27 0.377v

                            Comment


                            • #15
                              Pin 3 had a short so replaced ISL6259 and afterwards was 0.10V on pin 3 but 5V on pad one on R7110 R7111 and C7111 for a short bit and now 0V again and short returned.

                              This is the 3rd ISL 6259 I have replaced on this board now.

                              Comment

                              thread bottom ad

                              Collapse
                              Working...
                              X