LG 42LF561v picture dimming

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  • solval
    New Member
    • Jun 2021
    • 3
    • UK

    #1

    LG 42LF561v picture dimming

    Hey guys

    Our tv picture is quite dim, barely watchable now even with backlight and brightness settings set to 100% but like I say not a total picture failure so was wondering if the fault is with the led's or the power supply board?
    Obviously don't want to waste my time and money replacing the led's if the problem just manifest itself again further down the line.


    Took some readings at the led connector which has just the 2 wires feeding the led's.

    On standby the pos pin reads around 270v though sometimes slightly more and sometimes slightly less, this may not be important but idk why it does that!

    On stdby the - pin reads around 112v but drops quite rapidly to 99v and below.

    Powered On the + pin reads a steady 275v.
    Powered On the - pin reads 00.0

    I know it's only a entry level tv about 3 years old and probably not worth the hassle but kinda curious if I can fix it up. Would appreciate any help guys.
  • ReeceyBurger123
    Never Give Up !
    • May 2014
    • 7325
    • Britain

    #2
    Re: LG 42LF561v picture dimming

    Probably failing LEDs in the backlight, the 100% has prolly killed them.
    Please Do Not PM My Page Asking For Help Badcaps Is The Place For Advise, Page Linked For Business Reasons Only. Anyone Doing So Will Be Banned Instantly !

    https://www.facebook.com/Telford-Tel...7894576335359/

    Comment

    • alfatv
      Badcaps Veteran
      • Sep 2020
      • 353
      • Canada

      #3
      Re: LG 42LF561v picture dimming

      Originally posted by solval
      Powered On the + pin reads a steady 275v.
      Powered On the - pin reads 00.0
      Doesn't look right, could be open circuit, double check

      Comment

      • solval
        New Member
        • Jun 2021
        • 3
        • UK

        #4
        Re: LG 42LF561v picture dimming

        Originally posted by alfatv
        Doesn't look right, could be open circuit, double check
        Sorry for late reply. I did double check at the time. Will have another look tomorrow if I have the time. Sorry I'm not experienced in this at all and was hoping to see an easy fix like a blown cap on the board or something similar then I would have taken the board to a local repair shop to fix.

        Why would the - pin read zero, is that what you mean by an open circuit, possibly in the LEDs? Why the dim picture? Are all the LEDs only semi bright or could 1 or 2 of the presumably 4 LED strips have fried?

        On the male part of the LED connector there are 4 pins would it help if I read these? Though 2 of the 4 pins as far as I can see are not connecting to anything. Sorry for the dumb questions.

        Comment

        • sintv
          Member
          • Feb 2015
          • 37
          • scotland

          #5
          Re: LG 42LF561v picture dimming

          LGs have notoriously bad LED strips. Dismantle set and check strips preferably with power supply or youll have to turn it on without screen and screen panels to see what strips are out. Also if picture is blue, thats also LED problems. But your gonna have to strip it down.

          Comment

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