Insignia NS-50D40SNA14 backlight only stays on for a few minutes.

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  • mattpd
    Badcaps Veteran
    • Oct 2012
    • 302
    • USA
    #1

    Insignia NS-50D40SNA14 backlight only stays on for a few minutes.

    This is a LED set.

    When you turn it on and the screen is still black you can notice that the backlight is very uneven and splotchy.

    Once the picture comes up the set looks decent and is watchable. After about 15 minutes the backlight will shut off.

    I decided to heat the backlight driver area and was able to force the backlight to shut. So I thought I could replace the backlight driver and it would fix it, but it didn't. Same problem remains. I also changed to MOSFET that is in the same area but the problems remained.

    I then decided to heat up all the electrolytic caps I could find but this did not cause the backlight to shut down. Only heating the driver area would cause it.

    So instead I bought a new power board all together. It was a "no power" board from eBay, so I changed the fuse and replaced the two shorted FETs and it powered up fine. But just like the last board the backlight shuts off after about 15 minutes. So I am ready to rule out the board now.

    Could a bad LED string cause the backlight driver to overheat and shut off like this? Like I said the backlight coverage is very uneven and splotchy so maybe some of the LEDs are burnt out of malfunctioning? That's my theory at least.
    Tags: None
    • Diah
      Badcaps Legend
      • Feb 2013
      • 6435
      • Germany
      #2
      Re: Insignia NS-50D40SNA14 backlight only stays on for a few minutes.

      i had ones on Philips 65 size, it work fine and after less than 10 minutes BL get off, never found the reason until i had take it in parts and found 4 LEDs are flashing at normal working then they gone off so all BL went off and report error to NVM. would suggest take it in parts and watch by eyes to leds

        Comment

        • ReeceyBurger123
          Never Give Up !
          • May 2014
          • 7325
          • Britain
          #3
          Re: Insignia NS-50D40SNA14 backlight only stays on for a few minutes.

          If its a full array type of Led backlit Tv normally the little branch off connections break down and become intermittent. Try taking it apart and see if any of the Led strips start to flicker when it fails.
          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

            • mattpd
              Badcaps Veteran
              • Oct 2012
              • 302
              • USA
              #4
              Re: Insignia NS-50D40SNA14 backlight only stays on for a few minutes.

              I took it all the way apart to find an array of back light LEDS.

              There are 32 individual LEDS divided up on 8 strips with 4 LEDs on each strip.

              Out of the 32 LEDs two of them are not functioning. They are obviously burnt.

              I would like to replace these two faulty LEDs. Anyone know what package these are? And is there any way to tell what wattage they are?
              Attached Files

                Comment

                • Diah
                  Badcaps Legend
                  • Feb 2013
                  • 6435
                  • Germany
                  #5
                  Re: Insignia NS-50D40SNA14 backlight only stays on for a few minutes.

                  read my post on led back light suggestion

                  https://www.badcaps.net/forum/showpo...95&postcount=1

                    Comment

                    • ReeceyBurger123
                      Never Give Up !
                      • May 2014
                      • 7325
                      • Britain
                      #6
                      Re: Insignia NS-50D40SNA14 backlight only stays on for a few minutes.

                      They are 0.5w 3.5v 400ma Smt Leds. Finding replacements is hard and using 1w IMO makes the display look splotchy as they are too bright. I will link my method of repair which normally works out good.
                      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

                        • ReeceyBurger123
                          Never Give Up !
                          • May 2014
                          • 7325
                          • Britain
                          #7
                          Re: Insignia NS-50D40SNA14 backlight only stays on for a few minutes.

                          Link to video it also covers how to prevent the branch connectors from breaking down:

                          https://m.youtube.com/watch?v=RxwdC7V5Ue0
                          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

                            • mattpd
                              Badcaps Veteran
                              • Oct 2012
                              • 302
                              • USA
                              #8
                              Re: Insignia NS-50D40SNA14 backlight only stays on for a few minutes.

                              They are 3mmx3mm squares.

                              They look to be 5000k temperature.

                              The LEDs glow brightly around 5 volts.

                              Any help finding replacements?

                              The back looks like this:

                              EDIT: I just saw the posts above. Thanks.
                              Attached Files

                                Comment

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