Acer Aspire A515-56 Main FH5AT LA-K093P no power

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Egidio85
    Member
    • Jul 2019
    • 38
    • italia

    #1

    Acer Aspire A515-56 Main FH5AT LA-K093P no power

    Hi everyone, I was looking for some advice on an Acer Aspire A515-56 with a FH5AT LA-K093P motherboard.

    the PC does not turn on, the battery is completely dead.

    checking the board I do not detect shorts.

    the 19v of the charger stops at the first mosfet PQB3

    on PUB1 BQ24781 pin 28 I have 19v.

    connecting with a bench power supply I have no absorption.

    nothing that heats up with a thermal camera.

    any advice on what to check?

    thanks in advance​
  • mon2
    Badcaps Legend
    • Dec 2019
    • 13830
    • Canada

    #2
    Hi. Yes, review the detailed sticky article above by piernov on charger circuits.

    Remove all power. Meter in resistance mode.

    Measure the resistance across the first DCin mosfet:

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


    Post each measurement. Each measurement must be hundreds of k ohms or higher else could be shorted. Repeat for the 2nd DCin mosfet.

    Also check the resistance to GROUND of the 2nd DCin mosfet - test the source (1-2-3) pins and also the drain pins (5-6-7-8). We are checking this to confirm the final output of these DCin mosfets is not shorted for the main power rail which may be the reason for the damage of the DCin mosfets.

    Being N-channel mosfets, the gate pin of both DCin mosfets should be = adapter_voltage + REGN voltage = ~25v to fully enable.

    Comment

    • Egidio85
      Member
      • Jul 2019
      • 38
      • italia

      #3
      thanks for the reply, here is the measurement

      first mosfet PQB3

      source (1-2-3) & drain (5-6-7-8). 67K ohm
      source (1-2-3) & gate (4). 85K ohm
      gate (4) & drain (5-6-7-8)
      1.2M ohm

      second mosfet PQB4

      source (1-2-3) & drain (5-6-7-8). 800K ohm
      source (1-2-3) & gate (4). 600K ohm
      gate (4) & drain (5-6-7-8)
      800K ohm

      second mosfet PQB4

      gnd source (1-2-3)​ 110K ohm
      gnd drain (5-6-7-8). 6K ohm

      Comment

      • mon2
        Badcaps Legend
        • Dec 2019
        • 13830
        • Canada

        #4
        Flux and replace the first Dcin mosfet at PQB3.

        Comment

        • mcplslg123
          Badcaps Legend
          • Jun 2015
          • 7262
          • india

          #5
          DC jack often fails on this board blocking 19V.Check it to be sure.

          Comment

          • Egidio85
            Member
            • Jul 2019
            • 38
            • italia

            #6
            Originally posted by mon2
            Flux and replace the first Dcin mosfet at PQB3.
            changed the first mosfet. same situation, behavior does not change

            Comment

            • mon2
              Badcaps Legend
              • Dec 2019
              • 13830
              • Canada

              #7
              Click image for larger version  Name:	IMG_4748.jpg Views:	0 Size:	44.5 KB ID:	3647218

              Which mosfet was used for the replacement? With no power, share the same resistance checks for this new mosfet.

              Then, attach the power adapter and carefully measure the voltage to ground for the following pins:

              Using BQ24780S as reference which is with the same pinout -

              REGN
              VCC
              ACDRV
              ACOK


              Also ACDET.


              Last edited by mon2; 05-28-2025, 05:36 AM.

              Comment

              • mon2
                Badcaps Legend
                • Dec 2019
                • 13830
                • Canada

                #8
                As per post #5 - confirm the attached which may be the root cause. We have seen this a few times on this forum.

                In summary - the ADAPDET pin on the power connector is failing to provide the 0V or GROUND. Respectively, the ACDET voltage is then pulled to ground due to the mosfet @ PQ101.

                As a test, you can connect a piece of wire to the gate pin of PQ101 to GROUND which will force PQ101 to DISABLE. Then ACDET should follow a voltage suitable to enable the mosfets.

                Click image for larger version  Name:	adapdet.png Views:	0 Size:	78.4 KB ID:	3647314

                Comment

                • Egidio85
                  Member
                  • Jul 2019
                  • 38
                  • italia

                  #9
                  Originally posted by mon2
                  As per post #5 - confirm the attached which may be the root cause. We have seen this a few times on this forum.

                  In summary - the ADAPDET pin on the power connector is failing to provide the 0V or GROUND. Respectively, the ACDET voltage is then pulled to ground due to the mosfet @ PQ101.

                  As a test, you can connect a piece of wire to the gate pin of PQ101 to GROUND which will force PQ101 to DISABLE. Then ACDET should follow a voltage suitable to enable the mosfets.

                  Click image for larger version Name:	adapdet.png Views:	0 Size:	78.4 KB ID:	3647314

                  Thanks for the advice, by putting pin number 2 of the PQ101 to ground the PC started working again. Can I leave it like this? Or could it cause problems?

                  Comment

                  • mon2
                    Badcaps Legend
                    • Dec 2019
                    • 13830
                    • Canada

                    #10
                    You can leave this wire jumper and use the laptop like normal. The root cause is as noted by mcplslg123, the dcin power adapter connecter is likely loose for this pin that should have pulled this mosfet gate pin to ground.

                    The manual wire jumper now performs the same task.

                    Comment

                    • Egidio85
                      Member
                      • Jul 2019
                      • 38
                      • italia

                      #11
                      ok, thank you so much for your help

                      Comment

                      • mcplslg123
                        Badcaps Legend
                        • Jun 2015
                        • 7262
                        • india

                        #12
                        Wiser to replace the DC jack as it already shows signs of failure. Why risk it?

                        Comment

                        Related Topics

                        Collapse

                        • Document Archive
                          ACER Aspire Aspire X3910 Aspire E5700 Specification for Upgrade or Repair
                          by Document Archive
                          This specification for the ACER Aspire Aspire X3910 can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the Aspire Aspire X3910 boardview and Aspire Aspire X3910 schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet, or...
                          09-12-2024, 03:36 PM
                        • Document Archive
                          ACER Aspire Aspire XC-330 Aspire XC A4-9120e Specification for Upgrade or Repair
                          by Document Archive
                          This specification for the ACER Aspire Aspire XC-330 can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the Aspire Aspire XC-330 boardview and Aspire Aspire XC-330 schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet,...
                          09-12-2024, 03:30 PM
                        • Document Archive
                          ACER Aspire Aspire XC-886 Aspire XC i5-9400 Specification for Upgrade or Repair
                          by Document Archive
                          This specification for the ACER Aspire Aspire XC-886 can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the Aspire Aspire XC-886 boardview and Aspire Aspire XC-886 schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet,...
                          09-12-2024, 03:30 PM
                        • Document Archive
                          ACER Aspire Aspire GX-281 A710504 NL1 Aspire GX 1700 Specification for Upgrade or Repair
                          by Document Archive
                          This specification for the ACER Aspire Aspire GX-281 A710504 NL1 can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the Aspire Aspire GX-281 A710504 NL1 boardview and Aspire Aspire GX-281 A710504 NL1 schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties...
                          09-12-2024, 03:28 PM
                        • Document Archive
                          ACER Aspire Aspire TC-885 I5618 BE Aspire TC i5-8400 Specification for Upgrade or Repair
                          by Document Archive
                          This specification for the ACER Aspire Aspire TC-885 I5618 BE can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the Aspire Aspire TC-885 I5618 BE boardview and Aspire Aspire TC-885 I5618 BE schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any...
                          09-12-2024, 03:28 PM
                        • Loading...
                        • No more items.
                        Working...