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    #1

    LG 32LG60-UA no picture

    I got a LG 32LG60-UA LCD TV that have no picture. It powers up, the backlight works, but there's no picture.

    I have no LVDS signal at all at the P900 connector going to the T-CON board. Not even the clock signal.

    Do you have a service manual for this TV set? All I can find is service manuals for the 37LG60 and the 42 LG 60. They have a similar main board but they have a second LVDS cable while the 32LG60 only has one.

    Also, some resistors around the P900 LVDS connector seem to have been messed width. Do you have a hi-res picture of the resistors around the P900 connector.

    Thanks.
    Tags: None
    #2
    Re: LG 32LG60-UA no picture

    LG SCARLET 32LG60 Service Manual
    Attached Files

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      #3
      Re: LG 32LG60-UA no picture

      Thanks. I've already seen this one. It is for the 32LG60-UR, not for the 32LG60-UA. Very different model for another country.

      Comment

        #4
        Re: LG 32LG60-UA no picture

        Post a picture of your board with the EAX/EBR code so we can know what LVDS connector you're talking about.

        Looking at a picture of an EBR55262601 it shows that infamous main chip LG has included in the LG series, it has a ton of problems with BGA solder cracking over time.

        Some of these SMD alluminium capacitors also dry up and stop functioning properly, especially those 16V 100uF near the RAM which handle the most stress.

        First thing would be to check if you have sound, even if you can't see you can input audio to every port, one of them has to be selected by the TV.

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          #5
          Re: LG 32LG60-UA no picture

          I know there's some life in there. It chimes when it powers up. As I said, I don't see any signal on an oscilloscope from any of the LVDS channels, even from the clock.

          This model (32LG60-UA) doesn't have a logic control board like its big bothers 37" and 42" models. The signal to the LVDS cable comes straight from the main chip. Your assumption of cracked BGA balls may be right.

          I've already tested all capacitors using an ESR meter. Some border line ones but no obviously failed ones.

          Anyway, here are the pictures you asked for. Check the one showing the LVDS connector. Some resistors have been messed up with. The 37LG60-UA service manual shows these resistors, but some are used to configure LCD panel options. When I compare them with the high res picture of that board you can see on the ShopJimmy.com website, I can see that they also look like they have been messed with. Probably all the resistors are populated at the factory and they are then ripped off the board to configure the LCD panel options. But I doubt that this is the problem since I don't have a wrong signal. I have no signal at all.

          I like to repair those boards instead of swapping them with used ones bought from eBay. You never know if these boards are indeed working at the first place.

          Thanks for your help.
          Attached Files

          Comment

            #6
            Re: LG 32LG60-UA no picture

            This board is rare, and every photo of an used one I could find had oxidation or a lot of flux around these resistors, so it's hard to see which ones are populated originally, your best bet is asking a seller to take a close up pic of the LVDS connector.

            The 32LG70-UA also shares the same T-CON board, but the connector is facing upwards instead of 90 degress and is hard to understand the resistors layout comparing them side by side.

            https://www.electronica-pt.com/esque...s-la86b-25267/ service manual for 32LG70-UA, see if this one has only one LVDS like yours.

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              #7
              Re: LG 32LG60-UA no picture

              I was unable to get a seller to send me a closeup picture of the resistors around the LVDS connector. So I did bite the bullet and bought one from tvparts.ca.

              The board I received is working just great. And I'll use it to help me diagnose and repair the bad one.

              For now, here are the resistors that are populated around the P900 LVDS connector on the 32LG60 variant:

              On the left:
              R965: Missing
              R990: Missing
              R991: 0 ohm

              On the underside (from left to right, the ones not mentioned are populated and are 0 ohm resistors):
              R943: 1K ohm (very badly soldered (cold joints), upside down, it even fell from the board when I measured it).
              R942: Missing
              R962: Missing
              R963: Missing
              R971: Missing
              R976: Missing
              R944: Missing
              R941: Missing
              R984: Missing
              R985: Missing

              As I said I'll continue working on the bad board and I'll publish any results.

              The attached picture is from the good board.
              Attached Files
              Last edited by Yanleb; 11-03-2021, 10:03 PM.

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                #8
                Re: LG 32LG60-UA no picture

                Just a quick update. I've compared the voltages at all the electrolytic capacitors between the good main board and the bad one. They are all the same within a few mV. So I'm not missing any voltage rail.

                Next step is to reflow the main IC (IC100), maybe reball it (yeah, I don't have a BGA rework station, but I have an electronic hotplate and a thermal camera).

                Comment

                  #9
                  Re: LG 32LG60-UA no picture

                  Reflow of the main IC (IC100) was the fix. TV set is now working like a new one.

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