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    LG 34UM59 white “washed out” image

    Hello everyone and thanks in advance for the support!
    I have an LG 34UM59 that has a white “washed out” image defect (see last picture).
    I was in a hurry and ordered already the mainboard to try the replacement (hoping that the fault is there...)
    But I have a question.. I disassembled all the monitor and found the tcon board ( which in my case is divided in two segments, linked by a flat cable).On the first segment there are some chips similar to the A15 you spoke about and which I found on various threads on internet. But they all have different names from A15.. if the new mainboard won't fix the problem, what chip do you think is responsible for the white image fault? I attached the photos of the board and the chip..
    Oh and.. I tested alle the VGL,VGH,VCOM voltages on the tcon board, none of them is 0v..
    Thank you very much in advance!!!

    In the photos you'll find:
    1-mainboard and its 2 flat cables going down to the 1st tcon
    2-tcon board (1st segment)
    3-tcon board (2nd segment, linked to the 1st by the flex cable)
    4/5/6- some particular chips that may help us troubleshooting
    7-image defect
    Attached Files
    Last edited by occhia; 11-18-2020, 02:16 AM.

    #2
    Re: LG 34UM59 white “washed out” image

    replace t-con

    Comment


      #3
      Re: LG 34UM59 white “washed out” image

      Thanks for the reply.
      The big problem is that the two tcon boards have 4 flat cables each and this cables going to the display panel are DIRECTLY soldered to the tcon and the panel...
      In fact I can’t detach them because I won’t be able to resolder them..maybe the only way is to find the integrated chip which is giving problems

      Comment


        #4
        Re: LG 34UM59 white “washed out” image

        Originally posted by occhia View Post
        Hello everyone and thanks in advance for the support!
        I have an LG 34UM59 that has a white “washed out” image defect (see last picture).
        I was in a hurry and ordered already the mainboard to try the replacement (hoping that the fault is there...)
        But I have a question.. I disassembled all the monitor and found the tcon board ( which in my case is divided in two segments, linked by a flat cable).On the first segment there are some chips similar to the A15 you spoke about and which I found on various threads on internet. But they all have different names from A15.. if the new mainboard won't fix the problem, what chip do you think is responsible for the white image fault? I attached the photos of the board and the chip..
        Oh and.. I tested alle the VGL,VGH,VCOM voltages on the tcon board, none of them is 0v..
        Thank you very much in advance!!!

        In the photos you'll find:
        1-mainboard and its 2 flat cables going down to the 1st tcon
        2-tcon board (1st segment)
        3-tcon board (2nd segment, linked to the 1st by the flex cable)
        4/5/6- some particular chips that may help us troubleshooting
        7-image defect
        connect this LG Monitor to PC and change the resolution of the pc each time... show us the result with photos over here and don't forget to write on each photo which Resolution it was.

        Comment


          #5
          Re: LG 34UM59 white “washed out” image

          Here I am!
          These are the 3 photos:
          -2560x1080
          -1920x1080
          -1280x720

          Then I noticed a thing! That area circled in red is emitting a strange noise like a light whistle.
          When I touch with my finger that noise change tone and the screen shows images better (I mean with less white shadow on it)

          Any suggestions?
          THANKS A LOT!
          Attached Files

          Comment


            #6
            Re: LG 34UM59 white “washed out” image

            Another thing: the more the monitor stays ON, the more the picture becomes better and the shadow become less white ( obviously it stays there...) (see picture attached)

            Thanks
            Attached Files
            Last edited by occhia; 11-18-2020, 06:25 AM.

            Comment


              #7
              Re: LG 34UM59 white “washed out” image

              occhia.....
              Use your meter set to ohms and check there are no short circuits across any of the capacitors on that circuit board. I am sure that someone recently had a washed out picture that turned out to be a short circuit smd capacitor.
              Willing to help but I'm no expert.

              Comment


                #8
                Re: LG 34UM59 white “washed out” image

                Keep yours LG Monitor turning on and connect with your PC on Resolution 1920x1080, take hair dryer and heat the area of IC on MB where the LVDS going to the panel T-CON.

                Power boards show it to us too.

                the spark light you saw on T-CON related on some one disassembly the panel before.. and chassis ( screws ) connection still missing.

                Comment


                  #9
                  Re: LG 34UM59 white “washed out” image

                  Originally posted by dick_barton View Post
                  occhia.....
                  Use your meter set to ohms and check there are no short circuits across any of the capacitors on that circuit board. I am sure that someone recently had a washed out picture that turned out to be a short circuit smd capacitor.
                  I'm not expert on this.. I have to do it how? Without powering on the monitor? Thanks

                  Comment


                    #10
                    Re: LG 34UM59 white “washed out” image

                    Originally posted by Diah View Post
                    Keep yours LG Monitor turning on and connect with your PC on Resolution 1920x1080, take hair dryer and heat the area of IC on MB where the LVDS going to the panel T-CON.

                    Power boards show it to us too.

                    the spark light you saw on T-CON related on some one disassembly the panel before.. and chassis ( screws ) connection still missing.
                    I attached a photo of the mainboard (which is also the power board I think)

                    Sorry but I didn't understand.. so I have to heat the mainboard or the tcon?
                    And..what do you mean with the last phrase? Thanks a lot
                    Attached Files

                    Comment


                      #11
                      Re: LG 34UM59 white “washed out” image

                      Yes, set meter to 200 ohms or so, tv unplugged/not powered, probe on each end, see if you get very low ohms reading, probably expect to see over 100 ohms on most.

                      Comment


                        #12
                        Re: LG 34UM59 white “washed out” image

                        Mainboard and powerboard are usually 2 separate boards, can you go ahead and post good straight on pics. of all the boards and one of the whole back as to see how they are all connected?

                        Comment


                          #13
                          Re: LG 34UM59 white “washed out” image

                          Originally posted by occhia View Post
                          I attached a photo of the mainboard (which is also the power board I think)

                          Sorry but I didn't understand.. so I have to heat the mainboard or the tcon?
                          And..what do you mean with the last phrase? Thanks a lot
                          the area you show us at the panel t-con. its High freq discharge circuit, they are not defect ( you can see they make cut at boards to have distance from other parts. noise can be heard at any High freq Circuit. if the panel was taken apart before and not all designed screws in place it will make noise.

                          Power boards are external it had build in Step up currents circuit. ( mean at any level of Resolution's the power boards will feed high currents to support the displaying.

                          i never said heat the T-CON.. i wrote MB mean Main boards..lol

                          Comment


                            #14
                            Re: LG 34UM59 white “washed out” image

                            Attached there is the entire situation photo.

                            I am the only one that has disassembled this monitor, it was pretty perfect and the hooks of the chassis and the screws were all perfect...

                            So I have to test all the capacitors right? Or the resistors? And only in that high freq area?

                            Finally, are you sure that applying a lot of heat on the motherboard doesn't make any more damage?

                            Thank you guys.
                            Attached Files

                            Comment


                              #15
                              Re: LG 34UM59 white “washed out” image

                              Originally posted by occhia View Post
                              Attached there is the entire situation photo.

                              I am the only one that has disassembled this monitor, it was pretty perfect and the hooks of the chassis and the screws were all perfect...

                              So I have to test all the capacitors right? Or the resistors? And only in that high freq area?

                              Finally, are you sure that applying a lot of heat on the motherboard doesn't make any more damage?

                              Thank you guys.
                              LOL... are you Italian People always change the words from A to Z.
                              Can you tell us where did you read the words ( a lot of heat )

                              did the hair dryer burn your hairs when you use it ???

                              Power boards... mean your external Power Supply... is it Original..!!!
                              how much .V DC and .A ? did you know how to exam it if its A output can handle the level as its written on the label of it.. ??

                              Comment


                                #16
                                Re: LG 34UM59 white “washed out” image

                                Ok sorry! I was just scared about applying heat there. I can try.
                                Yea the power supply is original from LG. Yes I know how to test the V but I'm not sure on how test the Ampere... it has to be plugged in the monitor? can you guide me?

                                Comment


                                  #17
                                  Re: LG 34UM59 white “washed out” image

                                  I have an update. The monitor is ON from about 1.5h now. And it is seeing quite good. There’s still a little bit of that white shadow and some image ghost from previous pictures on the screen(circled in red).. can this info help us to troubleshoot the problem?
                                  Thanks
                                  Attached Files

                                  Comment


                                    #18
                                    Re: LG 34UM59 white “washed out” image

                                    you are jumping and ignore my suggestion test.. so i cant follow with you.. and its not good if i write wrong judgment on this issue..

                                    yours Monitor if now turn it off and then turn it on it will display same good image... but if you turn it off and leave it about 30 minutes it will have the bad washed image again.. reasons allot include bad panel..

                                    so go back and read what i suggest you please to narrow the issue... other wise wait till your replacement Main boards arrived ... and if no change then come back here to tell us the result.
                                    Last edited by Diah; 11-18-2020, 07:57 AM.

                                    Comment


                                      #19
                                      Re: LG 34UM59 white “washed out” image

                                      Ok, tests done.
                                      The power supply is giving out 19,5v (on the label it says 19v).
                                      The ampere I don't know how to test it properly, with the monitor unplugged it give a changing value and not steady.

                                      I applied the heat for about 3 minutes on the MB but nothing changed.

                                      Thank you

                                      Comment


                                        #20
                                        Re: LG 34UM59 white “washed out” image

                                        Occhia this is a Monitor so you are in the wrong section. Usually that defect is due to a bad gamma chip, in your case is the leftmost bigger one that probably is also a pmic, since it get better with time so you must try a reflow of it, or a resodering. Is it a job for you? If not an assistance center can help you.

                                        Comment

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