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    Need help reading schematic for Toshiba motherboard

    Hi,

    I have a L855-11K Toshiba with this MB DK10FG-6050A2491301-MB-A02. The power was applied with reverse polarity and now their is no power lights. I am getting voltage up to the battery terminal but only 3.1v
    I downloaded the schematic but I am noob at reading them.
    Could anyone with experience direct me to the component that would have been damaged, or the section I should be focused in the schematic. I am not seeing any burned out Mosfets or diodes and both fuses test ok.
    I am getting a pulsing reading of 7.x and 8.x vdc out of Q6010 and Q6011 Mossfet's at the pwr connector.
    I don't understand the schematic as the voltage is not listed, and as I said I am learning.

    Thanks in advance.
    Attached Files

    #2
    Re: Need help reading schematic for Toshiba motherboard

    check fuse6000 & coil L7600 post result.

    Comment


      #3
      Re: Need help reading schematic for Toshiba motherboard

      And fuse 6050? Picture of your board may help as schematics do not always match the board exactly
      Please upload pictures using attachment function when ask for help on the repair
      http://www.badcaps.net/forum/showthread.php?t=39740

      Comment


        #4
        Re: Need help reading schematic for Toshiba motherboard

        aanan,
        I get 19v past fuse 6000 and coil L7600, in fact I get -19v and +3.1 @ battery connector.

        selldoor,
        Fuse 6050 is showing +3.1v I will post pics and notes tomorrow, I am away from the mb.

        I appreciate you guys helping!

        Comment


          #5
          Re: Need help reading schematic for Toshiba motherboard

          as first measure the voltage on every big coil on board

          Comment


            #6
            Re: Need help reading schematic for Toshiba motherboard

            "I get 19v past fuse 6000 and coil L7600, in fact I get -19v and +3.1 @ battery connector" Are you getting MINUS 19VDC at fuse 6000, COIL L7600? What are you using for ground ref for the black probe, it should not show negative number.
            What DC do you get at the VCC pin of the U6000 pin 20?
            "The power was applied with reverse polarity " Do you also know how high of the reverse Voltage was applied to the DC input jack?
            Last edited by budm; 07-15-2014, 10:02 PM.
            Never stop learning
            Basic LCD TV and Monitor troubleshooting guides.
            http://www.badcaps.net/forum/showthr...956#post305956

            Voltage Regulator (LDO) testing:
            http://www.badcaps.net/forum/showthr...999#post300999

            Inverter testing using old CFL:
            http://www.badcaps.net/forum/showthr...er+testing+cfl

            Tear down pictures : Hit the ">" Show Albums and stories" on the left side
            http://s807.photobucket.com/user/budm/library/

            TV Factory reset codes listing:
            http://www.badcaps.net/forum/showthread.php?t=24809

            Comment


              #7
              Re: Need help reading schematic for Toshiba motherboard

              budm,
              I am getting Positive 19vdc at at fuse 6000, COIL L7600.
              I am using an alligator clip on gnd through holes on MB.
              The VCC pin of the U6000 pin 20 = Pos 18.9vdc
              The reverse polarity applied was 19.5vdc, (I did it by mistake with a wrong adaptor on a universal charger when it fell off.)

              selldoor, I attached photo's with some details as you suggested, fuse 6050 is Pos 3.1vdc

              aanan, Pos 19vdc at 6000, COIL L7600

              I will upload any other details and follow your suggestions, please be patient with me as I am in the EU and our time may not match!

              I am very appreciative of you guys helping!
              Attached Files
              Last edited by tonylock; 07-16-2014, 08:56 AM.

              Comment


                #8
                Re: Need help reading schematic for Toshiba motherboard

                Id say get the voltages on the other coils and add info to your pics which are good.
                Please upload pictures using attachment function when ask for help on the repair
                http://www.badcaps.net/forum/showthread.php?t=39740

                Comment


                  #9
                  Re: Need help reading schematic for Toshiba motherboard

                  selldoor,

                  Please find revised photo with additional coils.

                  I was getting zero volts on L6100 and L6150 I reversed my test leads with Pos on the pos Pos in terminal, and neg on the coils and got 19.2vdc.
                  Attached Files
                  Last edited by tonylock; 07-16-2014, 10:16 AM.

                  Comment


                    #10
                    Re: Need help reading schematic for Toshiba motherboard

                    Right now if there is damages in the AC detect/charger section which is controlled by the IC U6000. If you are using the Batteries right now and it is still dead, then I believe that the MOSFET Q6012 (which is turned on when it is running on batteries, batteries voltage is applied to Source pins 1~3, the output comes out on Drain pin 5~8) is not being turned on by IC 6000. So try using the batteries to see if the computer will run (do not have the AC adapter connected).
                    Check the DC Voltage on the Gate pin 4 of Q6012 with good batteries connected (no AC adapter connected).
                    Last edited by budm; 07-16-2014, 10:41 AM.
                    Never stop learning
                    Basic LCD TV and Monitor troubleshooting guides.
                    http://www.badcaps.net/forum/showthr...956#post305956

                    Voltage Regulator (LDO) testing:
                    http://www.badcaps.net/forum/showthr...999#post300999

                    Inverter testing using old CFL:
                    http://www.badcaps.net/forum/showthr...er+testing+cfl

                    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                    http://s807.photobucket.com/user/budm/library/

                    TV Factory reset codes listing:
                    http://www.badcaps.net/forum/showthread.php?t=24809

                    Comment


                      #11
                      Re: Need help reading schematic for Toshiba motherboard

                      budm,

                      It does not turn on with battery and no ac adaptor.
                      I do get much heat on the large chip to the right on the detail photo. (I'm not sure of reference number)
                      DC Voltage on the Gate pin 4 of Q6012 with good batteries connected is 18.1vdc

                      Comment


                        #12
                        Re: Need help reading schematic for Toshiba motherboard

                        Remove the batteries and then check the resistance between PVBAT and Ground to see what resistance you are getting.
                        Never stop learning
                        Basic LCD TV and Monitor troubleshooting guides.
                        http://www.badcaps.net/forum/showthr...956#post305956

                        Voltage Regulator (LDO) testing:
                        http://www.badcaps.net/forum/showthr...999#post300999

                        Inverter testing using old CFL:
                        http://www.badcaps.net/forum/showthr...er+testing+cfl

                        Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                        http://s807.photobucket.com/user/budm/library/

                        TV Factory reset codes listing:
                        http://www.badcaps.net/forum/showthread.php?t=24809

                        Comment


                          #13
                          Re: Need help reading schematic for Toshiba motherboard

                          Good Morning budm,

                          I tested between PVBAT and Ground, if I am correct on my ref.point and get 28.29K
                          Please check my ref point as I am not sure if it is correct.
                          Please see photo.
                          Thanks again for taking time to help.
                          Attached Files

                          Comment


                            #14
                            Re: Need help reading schematic for Toshiba motherboard

                            Tonylock, Hi. Have you found what the problem is? I have the same problem with this motherboard.

                            Originally posted by tonylock View Post
                            Good Morning budm,

                            I tested between PVBAT and Ground, if I am correct on my ref.point and get 28.29K
                            Please check my ref point as I am not sure if it is correct.
                            Please see photo.
                            Thanks again for taking time to help.

                            Comment


                              #15
                              Re: Need help reading schematic for Toshiba motherboard

                              Measure → V(TP(ACDET)) = 2.6 V ± 0.1 V
                              Measure → V(TP(ACOK)) = 3.3 V ± 0.1 V
                              Measure → V(J2(SYS)) = 19.5 V ± 0.5 V
                              Measure → V(TP(REGN)) = 6 V ± 0.5 V
                              Measure → V(TP(ACDRV, CMSRC)) = 6 V ± 0.5 V
                              Measure → V(J2(BAT, GND)) = 2 V ± 2 V



                              ACDRV must be 24V or 25V and CMSRC 18v or 19V

                              24-18=6V and 25-19=6V (correct voltage )

                              Comment


                                #16
                                Re: Need help reading schematic for Toshiba motherboard

                                Cannot work on battery because you don't have gnd on pin 8,9 of battery connector.

                                Normally with your multimeter you must have continuity between gnd reference and pin 8,9 of battery connector.

                                Comment


                                  #17
                                  Re: Need help reading schematic for Toshiba motherboard

                                  Hi, I have a question, does anyone know of what capacity these two capacitors are
                                  Attached Files

                                  Comment

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