LG 32 lcd not always turning ON

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  • nathaniel
    Member
    • Jan 2013
    • 35
    • israel

    #21
    Re: LG 32 lcd not always turning ON

    i added a picture of what i did:

    1k resistor ( rated 1/4w hope its ok) from the 5.2v to pin - inverter on/off
    1k resistor from the same 5.2v to pin - power_on

    with the a/c plugged in and the main board disconnected

    the power_on cam up to2.9v but still no other voltage beside the 5v

    am i doing it right?

    the board model: EAY4050440


    thank you guys
    Attached Files

    Comment

    • nathaniel
      Member
      • Jan 2013
      • 35
      • israel

      #22
      Re: LG 32 lcd not always turning ON

      so... does it mean the pson voltage is correct ?
      and the power board is at fault

      should i replace the capacitors or there is furhter checking to do?

      Comment

      • newtothis
        Badcaps Legend
        • Mar 2013
        • 1556
        • england

        #23
        Re: LG 32 lcd not always turning ON

        With jumpers in place check one of the main caps voltage with meter set to 600VAC, Careful HOT side of board. Take note of polarity

        Comment

        • nathaniel
          Member
          • Jan 2013
          • 35
          • israel

          #24
          Re: LG 32 lcd not always turning ON

          just to make sure ... i'm testing the two large capacitors marked c608 and c609

          and i still get 330v dc

          Comment

          • newtothis
            Badcaps Legend
            • Mar 2013
            • 1556
            • england

            #25
            Re: LG 32 lcd not always turning ON

            Do you want to repair the boards or replace them?

            Your PSU is faulty BTW

            Comment

            • nathaniel
              Member
              • Jan 2013
              • 35
              • israel

              #26
              Re: LG 32 lcd not always turning ON

              i would like to repair it if possible
              ordering a board will take 4-8 weeks with our %@@#$ post service

              do you think this is a capacitor symptom or somthing more compicated?

              Comment

              • CapLeaker
                Leaking Member
                • Dec 2014
                • 7972
                • Canada

                #27
                Re: LG 32 lcd not always turning ON

                Originally posted by nathaniel
                i would like to repair it if possible
                ordering a board will take 4-8 weeks with our %@@#$ post service

                do you think this is a capacitor symptom or somthing more compicated?
                I am hoping that this is the schematic for your board

                Does your board have the relay option?
                Attached Files
                Last edited by CapLeaker; 05-30-2015, 05:57 PM.

                Comment

                • nathaniel
                  Member
                  • Jan 2013
                  • 35
                  • israel

                  #28
                  Re: LG 32 lcd not always turning ON

                  no i don't have the relay option ...just the two jumpers instead

                  Comment

                  • CapLeaker
                    Leaking Member
                    • Dec 2014
                    • 7972
                    • Canada

                    #29
                    Re: LG 32 lcd not always turning ON

                    What kind of tools do you have? Do you have an ESR meter?
                    Try this: Heat up or cool the board and see if it turns on. If you need heat to turn on the PSU there is a bad cap somewhere.
                    Check the PSon circuit and the PFC circuit. Problems in either could do that. Make sure that the PSU is working correctly before you put that main board back on.

                    Comment

                    • victor_cj
                      Senior Member
                      • May 2015
                      • 90
                      • Romania

                      #30
                      Re: LG 32 lcd not always turning ON

                      Check or replace NCP1396AG and SG6961SZ and will work again.
                      The art of fighting without fighting

                      Comment

                      • nathaniel
                        Member
                        • Jan 2013
                        • 35
                        • israel

                        #31
                        Re: LG 32 lcd not always turning ON

                        update:
                        and an hour of heating and cooling the ps
                        i maneged to get it start twice ( while cooling)
                        i tried to freeze on area at a time with no success , only when i freeze the all board it will start. :/

                        victor- i don't believe ican test this components with a multimeter , can i?
                        if this is the case i think i would be better ordering a replacment board i'm not 100% i can properly solder such a part

                        Comment

                        • victor_cj
                          Senior Member
                          • May 2015
                          • 90
                          • Romania

                          #32
                          Re: LG 32 lcd not always turning ON

                          You can test it, depends on the your level of experience. At NCP1396AG check voltage pin12 Vcc, pin11 Mlower, pin9 Slow Fault. At SG6961SZ check voltage pin8 Vcc, pin7 Gd, pin1 Inv, pin5 Zcd.
                          The art of fighting without fighting

                          Comment

                          • nathaniel
                            Member
                            • Jan 2013
                            • 35
                            • israel

                            #33
                            Re: LG 32 lcd not always turning ON

                            thank again victor
                            i tried testing these i started testing this time the tv was on

                            NCP1396AG (test dc between a pin and the chip GND - don't know if it's correct)
                            pin 9- 65 mV
                            pin 11 - 7.2V
                            pin 12- 14.9V

                            SG6961SZ
                            pin 5 -2.8V (and pin 6 as GND) also when i touched with only one probe at pin 5 got a little buzzing from the board.



                            when tring to test pin 7 i accidently touched both 7+8 the main fuse got blown...
                            replaced it with another one and... blow again

                            probably shorted somthing else :/ hopefully on the same board so i'll only need to replace this one.

                            having fun learning electronic repairs

                            i'll update when i'll get a new board so i won't waist your time.

                            Comment

                            • victor_cj
                              Senior Member
                              • May 2015
                              • 90
                              • Romania

                              #34
                              Re: LG 32 lcd not always turning ON

                              Check Q601, Q602.
                              Another SMPS board it is best for you.
                              The art of fighting without fighting

                              Comment

                              • nathaniel
                                Member
                                • Jan 2013
                                • 35
                                • israel

                                #35
                                Re: LG 32 lcd not always turning ON

                                update:

                                got a replacment PS board from a local technician (didn't found the parts victor mentioned available here- so that was my only option)

                                just wanted to thank you all for your time - the TV WORKS AGAIN!!

                                THUMBS UP

                                Comment

                                • victor_cj
                                  Senior Member
                                  • May 2015
                                  • 90
                                  • Romania

                                  #36
                                  Re: LG 32 lcd not always turning ON

                                  Same EAY4050440 from 32LG2000 with PFC low, caused by R609, R610, R611, R612 620K ohms resistor.
                                  https://www.youtube.com/watch?v=uwWdRsMAcJU
                                  The art of fighting without fighting

                                  Comment

                                  • fredaelsadany
                                    Senior Member
                                    • Jan 2016
                                    • 66
                                    • EGYPT

                                    #37
                                    Re: LG 32 lcd not always turning ON

                                    Hallo every one
                                    please measure r613(15k)/r614(820ohm)
                                    thanks
                                    Attached Files

                                    Comment

                                    • Alastair E
                                      Chief Womble
                                      • Mar 2013
                                      • 1963
                                      • U.K.

                                      #38
                                      Re: LG 32 lcd not always turning ON

                                      There's a number of capacitors on the Mainboard along with some tiny inductors that can cause an Intermittent Dead LG...

                                      There's kits available showing whats needed, try googling the set model-number....

                                      An Observation--

                                      I notice in one of your pictures--Only Two Screws mounting the PSU.

                                      Make Sure you fit ALL screws to ALL boards Particularly on any Plasma set--Before trying to make the set work....
                                      Plasmas particularly can self-destruct if they have a missing earth screw....
                                      TELEFIX

                                      How PLASMA SCREENS WORK, X-SUS and Y-SUS what they do--
                                      http://www.irf.com/technical-info/appnotes/an-1088.pdf
                                      PLEASE DO NOT EMAIL ME PRIVATELY FOR REPAIR ADVICE. QUESTIONS BELONG ON THE FORUM!

                                      Comment

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