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lg 47LB585V help to identify ic please

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    lg 47LB585V help to identify ic please

    Hi this lg has a rediculously small 16 pin ic on mainboard cooking
    causing brief flash of sby led then dead its the one next to a coil 2r2
    reference ic2403 i cant make it out looks like:

    5419
    0rAA
    A36X
    this tv had bad b/l leds and i replaced all the strips with new
    they tested fine with led tester ,ifound the b/l controller ic s/c bl0202b and q803 s/c these were replaced but leds just flashed on for one second .
    to save time (big mistake) i ordered replacement psu from e bay
    when fitted it caused the mainboard problem grrr!
    now even my original psu wont start up
    ive tried to find cct for main board i can only find psu cct
    if someone can help me identify the ic or suggest why the rogue psu has caused the problem it would be a great help

    the rogue psu is:EAX65423801(2.1)REV 2.0
    the original psu is:EAX65423801(2.2)REV 2.1
    Attached Files

    #2
    Re: lg 47LB585V help to identify ic please

    ic2403 - TPS54319
    Attached Files

    Comment


      #3
      Re: lg 47LB585V help to identify ic please

      Originally posted by lotas View Post
      ic2403 - TPS54319
      many thanks ,now i have somewhere to start ,
      i suspect ,as it gets hot.
      something external to it is drawing current through it

      Comment


        #4
        Re: lg 47LB585V help to identify ic please

        service manual
        Attached Files

        Comment


          #5
          Re: lg 47LB585V help to identify ic please

          Originally posted by lotas View Post
          service manual
          thanks ,i have s/c on pins 1 and 2 to ground.
          im going to try to replace ,removal no problem with s station but fitting new will be a chalenge,
          im going to force on the psu without connecting main board and see if 3.3v supply is high ,do you think this could be the reason the ic failed?

          Comment


            #6
            Re: lg 47LB585V help to identify ic please

            If it exceeded more than 7v, then the IC could burn out.
            Attached Files

            Comment


              #7
              Re: lg 47LB585V help to identify ic please

              not looking good .pin 10,11,and12 .the 1.5v o/p s/c
              so protection zener zd2401 was never fitted
              so any number of components could be s/c

              Comment


                #8
                Re: lg 47LB585V help to identify ic please

                1.5v for power supply of random access memory (DDR).
                Attached Files

                Comment


                  #9
                  Re: lg 47LB585V help to identify ic please

                  If you lift L2411 are pins 10, 11 & 12 still short and if not is the other end of L2411 showing the short.
                  Willing to help but I'm no expert.

                  Comment


                    #10
                    Re: lg 47LB585V help to identify ic please

                    Originally posted by dick_barton View Post
                    If you lift L2411 are pins 10, 11 & 12 still short and if not is the other end of L2411 showing the short.
                    thanks for joining in the party mr b
                    when L2411 Lifted it measures 240 ohm .so not short but still a bit lower than i would expect ,what do you think?

                    Comment


                      #11
                      Re: lg 47LB585V help to identify ic please

                      Are you saying L2411 has a resistance of 240 ohms or the output of the IC (1.5V ) to ground measured 240 ohms.
                      What is the resitance with the meter on one pad of L2411 to ground and again what is the reistance from the other pad of L2411 to ground both checked with L2411 lifted.
                      If the resistance of the IC2403, pIns 10, 11 & 12 is 240 ohms to ground then that would appear to be OK.
                      Last edited by dick_barton; 12-12-2021, 09:45 AM.
                      Willing to help but I'm no expert.

                      Comment


                        #12
                        Re: lg 47LB585V help to identify ic please

                        the o/p of the coil when lifted is 240 ohm to deck ie the 1,5v supply 240 ohm
                        the other side is dead short to deck i know the tps54319 is duff
                        but i would expect a much higher value on the 1.5v o/p side
                        the coil itself is fine very low ohms

                        Comment


                          #13
                          Re: lg 47LB585V help to identify ic please

                          The 240 ohm reading would appear to be fine and is not a high load on the 1.5V supply
                          Willing to help but I'm no expert.

                          Comment


                            #14
                            Re: lg 47LB585V help to identify ic please

                            ok thats reassuring .ive found a scrap pana main board with similar ic so im going to practice removing and refitting on this .what is interesting is on the pana main board the o/p pins 10,11,12 read 3.9k to deck
                            i know all ccts differ so best not to read into this too much ,
                            i think the board came from a pana TX-L 32C5B

                            Comment


                              #15
                              Re: lg 47LB585V help to identify ic please

                              You may well be correct. Just looking at the application note show there are two mosfets connected in totem pole so the 240 ohms could well mean that one of the internal mosets is damaged.
                              Good luck with your repair. Use plenty of flux with the solder and be patient.
                              Willing to help but I'm no expert.

                              Comment


                                #16
                                Re: lg 47LB585V help to identify ic please

                                Originally posted by lotas View Post
                                ic2403 - TPS54319
                                a question for lotas
                                do you know if:
                                0101
                                5173
                                is same device ?
                                ive found one on a panasonic tx-l32c5b main board

                                Comment


                                  #17
                                  Re: lg 47LB585V help to identify ic please

                                  Originally posted by jimbofz View Post
                                  a question for lotas
                                  do you know if:
                                  0101
                                  5173
                                  is same device ?
                                  ive found one on a panasonic tx-l32c5b main board
                                  "5173" - This is your G5173.
                                  Check datasheets. Your family should be marked "54319".
                                  Attached Files

                                  Comment


                                    #18
                                    Re: lg 47LB585V help to identify ic please

                                    wow thanks for quick reply
                                    it looks the same BUT its o/p is: 1.8v not 1,5v
                                    its markings are :0101
                                    5173

                                    Comment


                                      #19
                                      Re: lg 47LB585V help to identify ic please

                                      Originally posted by jimbofz View Post
                                      wow thanks for quick reply
                                      it looks the same BUT its o/p is: 1.8v not 1,5v
                                      its markings are :0101
                                      5173
                                      Their output voltage is set by a resistor divider.

                                      Comment


                                        #20
                                        Re: lg 47LB585V help to identify ic please

                                        To test the mainboard, you need to dismantle the TPS54319 and connect an external laboratory power supply (+) to the L2411 with 1.5V - 2A.

                                        Comment

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