Announcement

Collapse
No announcement yet.

Lenovo S145-15IL won,t charge

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

    #21
    Measured the resistance of the mosfets

    PQ103
    S-D= 0.7 / 0.9
    S-G= 206
    G-D= 1.1

    PQ104
    S-D= 0.5
    S-G= 197
    G-D= 0.5

    Comment


      #22
      Unable to understand the measurements.

      Post a link to your meter's user manual in English. There must be a way to force the meter to measure the resistance.

      Resistance measurements will be in ohms.

      Place one meter probe on mosfet pin #1 and other probe on pin #8. This check is the source-drain resistance. Never any power to the board in resistance mode checking.

      Post the measurement and the units of measurement. Ohms, kohms, Megaohms, etc.

      Or take a pic of each measurement of your meter face.

      Comment


        #23
        Let's see if I can borrow a tester on Monday

        Comment


          #24
          Repeat the measurements
          PQ103
          SD= 0,7 / 0,9 M
          SG= 206 K
          GD= 1,1 M
          PQ104

          SD= 0,5 M
          SG= 197 K
          GD= 0,5 M

          I hope they go well this time

          Comment


            #25
            PQ103
            SD= 0,7 / 0,9 M
            SG= 206 K
            GD= 1,1 M
            PQ104

            SD= 0,5 M
            SG= 197 K
            GD= 0,5 M
            These measurements look low for a good mosfet. Consider to flux and remove off the board for additional testing. They may need to be replaced.

            Comment


              #26
              Since I have two identical cards inside, which I can use as donors, how much should those values be?

              Comment


                #27
                You can check Google for many of these articles / video tutorials on YT.

                A good mosfet should offer a high resistance of Mohms.

                Comment


                  #28
                  Originally posted by mon2 View Post
                  You can check Google for many of these articles / video tutorials on YT.

                  A good mosfet should offer a high resistance of Mohms.
                  Ok, thanks.


                  Do I take them apart and do the same measurements?

                  Comment


                    #29
                    Yes, flux it well -> hot air till the solder melts - be patient and protect other nearby parts with low air pressure. Parts that can melt should be shielded from the heat. Then remove off the board -> allow it to cool and test the mosfet again using the same method.

                    Comment


                      #30
                      Disassembled and re-measured

                      S-D = 1.1M on both

                      I have no readings on the others

                      Comment


                        #31
                        Check post #25 - the measurements in RED are of concern. Test those again.

                        Comment


                          #32
                          I have no measurements on the disassembled mosfets.

                          On the motherboard without mosfet between Source and Gate I have the same values as in post 25

                          Comment


                            #33
                            Sorry for my ignorance, but as I was saying I just started, I shouldn't find 9V on pin 5678 of PQ102, I understand this from the diagram.

                            Comment


                              #34
                              Did you say that you have a working unit of the same model available for measurements?

                              Comment


                                #35
                                No, only a donor board from which I have already taken some parts is not working, such as the mosfets on the primary and the bios chip

                                Comment


                                  #36
                                  Measure the voltage to ground of ACOK (pin # 5) on the charger IC (PU100).

                                  Comment


                                    #37
                                    Voltage to ground of pin 5 of PU100 2.5V.

                                    Can you tell me what Batt+ and V9B+ mean?

                                    Comment


                                      #38
                                      BATT+ is the junction where the battery is used as the power source. In this case, the power adapter's DCin mosfets will be OFF, the charger mosfets for the battery @ PQ103 & PQ104 will be OFF. The battery flow through mosfet @ PQ102 will be ON. This battery voltage is ~9 volts and is ample to power the logic board.

                                      Respectively, the V9B+ is the main power rail used to power the logic board. If the main power adapter is applied, then the ~19 volts will travel through the power path, through the enabled 2 x DCin mosfets to supply the ~19 volts onto the main power rail. In this case, since the power adapter is mated to the logic board, the battery charger mosfets will toggle on/off to regulate the proper battery charge voltage using mosfets PQ103 & PQ104 to a safe voltage. The current sense resistor in this battery charge circuit is monitored for safety.

                                      The main battery mosfet @ PQ102 will be OFF in this case since the main power adapter is powering the logic board.

                                      Comment


                                        #39
                                        Ok thanks, that's what I thought, I needed confirmation.

                                        What can you tell me about it?

                                        With power supply and without battery, voltage to ground of pin 5 of the PU100 2.5V.

                                        Comment


                                          #40
                                          See attached. Confirm if you have the 2 resistors onboard with a high side and a low side to lower the REGN voltage.

                                          Confirm if you have ~6 volts on one leg of resistor PR112.

                                          That is, with a 6 volt input, with PR112 & PR111, the ACOK voltage will be divided down.

                                          Can you confirm the resistance of PR111? PR112? Remove all power / remove the battery. Measure the resistance across each resistor to measure.

                                          Click image for larger version

Name:	ACOK.png
Views:	32
Size:	191.9 KB
ID:	3307220

                                          Comment

                                          Working...
                                          X