LG 37LC2DB (37LC2D?) sound issues

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  • Andy_Bee_1
    New Member
    • Jan 2012
    • 2

    #1

    LG 37LC2DB (37LC2D?) sound issues

    Hi there,

    I bought a LG 37LC2DB off a local guy knowing it had a problem with the main board, in that it could not show Analog/Digital TV through the aerial. However AUX, SCART & HDMI worked fine. He had been using the TV fine for Satellite & XBox.
    This was no problem for me as I live in an area which cannot receive TV through an aerial anyway.
    I installed the TV, plugged in the Cable box, Wii and Media Centre.
    Everything was fine, for a while....
    After about 20mins the sound started making VERY loud crackle & pop noises, then would die. Turning the TV off then on did not get the sound back, but if left for a couple of hours it would be fine again.
    A month on and this loss of sound is random, it can be after 2mins, or other times we can watch the TV all day without sound loss.

    Investigation:
    I took the back off and checked for signs of badcaps - Nothing obvious!
    I went on some TV spare parts websites, spoke to a few people and bought both mainboards and replaced them as recommended. Everything worked still, then after 15mins the sound died (but with no pop & crackle this time, just muted). Over weeks this pop & crackle before the muting has returned.
    As far as I can see it hasn't got anything to do with the other boards in the TV - inverter, LCD controller, buttons, side panel etc.

    Shall I just buy the caps for the PSU? Is this likely to be the problem? All symptoms of a bad PSU seem to degrade or kill the picture - picture is crystal clear on my TV.

    Any help gratefully appreciated :-)
    Last edited by Andy_Bee_1; 01-04-2012, 03:23 AM.
  • retiredcaps
    Badcaps Legend
    • Apr 2010
    • 9271

    #2
    Re: LG 37LC2DB (37LC2D?) sound issues

    Originally posted by Andy_Bee_1
    Any help gratefully appreciated :-)
    Pay close attention to the picture composition that PlainBill wants and PLEASE do NOT post pictures inline or offsite. See

    https://www.badcaps.net/forum/showpo...76&postcount=2
    --- begin sig file ---

    If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.

    We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.

    Please do not post inline and offsite as they slow down the loading of pages.

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    Comment

    • tom66
      EVs Rule
      • Apr 2011
      • 32560
      • UK

      #3
      Re: LG 37LC2DB (37LC2D?) sound issues

      This is caused by the capacitors on the 19V and/or 12V rail failing. They do not have to bulge to be failed and many Samwha capacitors that LG seems so fond of using are known to fail without bulging.

      Post a picture of the power supply - top and bottom - clear and focused around the capacitors and the power supply connectors.
      Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
      For service manual, schematic, boardview (board view), datasheet, cad - use our search.

      Comment

      • Andy_Bee_1
        New Member
        • Jan 2012
        • 2

        #4
        Re: LG 37LC2DB (37LC2D?) sound issues

        Thank you, I shall indeed take some photos and post them (hosting on this site)

        Comment

        • huggy25
          New Member
          • Jan 2012
          • 1

          #5
          Re: LG 37LC2DB (37LC2D?) sound issues

          Originally posted by tom66
          This is caused by the capacitors on the 19V and/or 12V rail failing. They do not have to bulge to be failed and many Samwha capacitors that LG seems so fond of using are known to fail without bulging.

          Post a picture of the power supply - top and bottom - clear and focused around the capacitors and the power supply connectors.
          Tom 66...... I have an LG37LC2DB television. Basically I would like to know if I could bring it to you to have a look at for me as it has a problem similar to Andy Bee 1
          where it will be ok for a while then it starts making loud crackling and pop noises and I lose the picture and it will not respond to the remote control.
          Thanks in advance.

          Comment

          • tom66
            EVs Rule
            • Apr 2011
            • 32560
            • UK

            #6
            Re: LG 37LC2DB (37LC2D?) sound issues

            Originally posted by huggy25
            Tom 66...... I have an LG37LC2DB television. Basically I would like to know if I could bring it to you to have a look at for me as it has a problem similar to Andy Bee 1
            where it will be ok for a while then it starts making loud crackling and pop noises and I lose the picture and it will not respond to the remote control.
            Thanks in advance.
            I don't really do TV repairs for people, as I don't have the time (just a student.) All I can suggest is you replace the mentioned capacitors; better yet, replace ALL of them, as they will fail eventually (Samwha are bad capacitors.)
            Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
            For service manual, schematic, boardview (board view), datasheet, cad - use our search.

            Comment

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