Announcement

Collapse
No announcement yet.

LA-D993P No power no charging

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

    LA-D993P No power no charging

    hello
    When you press the power button, the light turns on and off. It was working normally until a day ago. +3VALW ,+5VALW and power_sw have 5 volts, won't charge and won't turn on

    P65F
    LA-D993P REV 1.0

    #2
    Re: LA-D993P No power no charging

    After the lights turn OFF - do you still have the +3VALW ,+5VALW and power_sw voltages?

    Are you using the original and official power adapter ?

    Comment


      #3
      Re: LA-D993P No power no charging

      it was working with non original charger. The battery was not installed. When I arrived in the morning, I noticed that the device was not turning on. I tried with another original charger and it still didn't turn on.

      +3VALW ,+5VALW and power_sw 3 volts have

      Comment


        #4
        Re: LA-D993P No power no charging

        See attached.

        1) Start with the charger IC @ PU300.

        Attach a known good power adapter -> meter in DC volts scale (30v or higher).

        Carefully (!) measure the voltage of each of the highlighted IC pins.

        Interested in:

        Vcc (pin #28)
        REGN (pin # 24)
        ACDET (pin # 6)
        ACOK (pin # 5)
        ACDRV (pin # 4)


        Post each measurement.


        2) Next, remove all power / no battery.

        Meter in resistance mode -> check the resistance across the mosfet pins:

        PQ306 & PQ302

        source (1-2-3) & drain (5-6-7-8)
        source (1-2-3) & gate (4)
        gate (4) & drain (5-6-7-8)


        Post each resistance measurement and the scale used on your meter for the checks. As per above sticky from @Pienov - often the 2nd mosfet gets damaged.

        reference:
        http://electronicsbeliever.com/how-t...-is-defective/
        * see the section on resistance checks
        Attached Files

        Comment


          #5
          Re: LA-D993P No power no charging

          Vcc (pin #28) = 19.7 Voltage
          REGN (pin # 24) = 6 Voltage
          ACDET (pin # 6) ACOK ( = 2.7 Voltage
          pin # 5) = 3.3 Voltage
          ACDRV (pin # 4) = 25.8 Voltage


          PQ306 diod mode : 0.465 /
          source (1-2-3) & drain (5-6-7-8) = resistance mode :465 ohm
          source (1-2-3) & gate (4) = resistance mode :611ohm
          gate (4) & drain (5-6-7-8) = ---

          PQ302 diod mode : 0.513 /
          source (1-2-3) & drain (5-6-7-8) = resistance mode :513ohm
          source (1-2-3) & gate (4) = resistance mode :606 ohm
          gate (4) & drain (5-6-7-8) = ---

          Comment


            #6
            Re: LA-D993P No power no charging

            1) Charger IC voltages look good.

            2) The mosfet resistance readings are not ok if the readings are indeed in ohms.

            3) Remove all power and with flux and hot air, remove PQ302 off the board. Careful of the air pressure so that other tiny nearby parts do not go flying.

            Then wait for the removed mosfet to cool and check the resistance in the same way of the part that you have removed.

            Is the removed mosfet still with these very low readings?

            Also check the resistance values of the PQ306 mosfet (now that PQ302 is off the board and should not influence the measurements).

            Comment


              #7
              Re: LA-D993P No power no charging

              sorry
              I typed wrong kΩ

              https://we.tl/t-cfstD6JZ3t

              Comment


                #8
                Re: LA-D993P No power no charging

                Then the resistance appears to be ok for the mosfets.

                Before placing the mosfet back onto the board, check the resistance to ground of the removed mosfet pads:

                source (1-2-3)
                gate (4)
                drain (5-6-7-8)


                if the power is not remaining ON for the main power rail then you may have an excessive current draw which is being sensed -> could be a broken current sense circuit which will result in the same observation. Or the bios of the EC controller may need to be reflashed.

                Comment


                  #9
                  Re: LA-D993P No power no charging

                  source (1-2-3) = 398 kΩ
                  gate (4) = 416 kΩ
                  drain (5-6-7-8) = 130kΩ

                  i tried the bios

                  Comment


                    #10
                    Re: LA-D993P No power no charging

                    Looks ok.

                    Check the resistance to ground of each coil (inductor).

                    Comment


                      #11
                      Re: LA-D993P No power no charging

                      I checked the coils, there is no low resistance or short circuit.
                      When the device was in its last working state, the battery was not plugged in and the non-original charger was connected

                      The PS_ID line goes in MEC1404. Could the mec 1404 be faulty? Due to fake charger
                      Last edited by tipoti; 10-10-2022, 10:22 AM.

                      Comment


                        #12
                        Re: LA-D993P No power no charging

                        What is voltage of PS_ID ?

                        Comment


                          #13
                          Re: LA-D993P No power no charging

                          PS_ID =3.4 Voltage

                          Comment


                            #14
                            Re: LA-D993P No power no charging

                            I haven't been able to fix the problem yet
                            There is a working motherboard. does it help fix the other

                            Comment


                              #15
                              Re: LA-D993P No power no charging

                              Yes, it can help.

                              Does the working unit use the same or different power adapter?

                              Comment

                              Working...
                              X