Samsung 32" power supply BN44-0351B no backlight

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  • seve91
    Senior Member
    • Oct 2013
    • 75
    • Italy

    #61
    Re: Samsung 32" power supply BN44-0351B no backlight

    Originally posted by dskall
    Bright white which has a bluish tint. So I would say 5700K. Others will give yellowish tint
    unfortunately 5700k is too warm, i probably need 6500k.
    As you can see in the photo, you can easily find the replaced LEDs.



    Comment

    • dskall
      Badcaps Legend
      • Oct 2016
      • 2905
      • usa

      #62
      Re: Samsung 32" power supply BN44-0351B no backlight

      They look yellow to me. Look at color temp charts. Higher temps are bluer lower temps are yellow
      I assume no responsibility for any stupid suggestions I might post.

      Comment

      • seve91
        Senior Member
        • Oct 2013
        • 75
        • Italy

        #63
        Re: Samsung 32" power supply BN44-0351B no backlight

        Originally posted by R_J
        Why not try shorting PCS802S/B (e-c) if the QS801, etc. are ok the tv should turn on.
        Or try shorting QS871 e-c to see if the tv comes on
        Power on/off controls QS871, If QS871 is turned on it connects PCS802S/A to ground causing its led (in the optocoupler) to light.
        yes, shorting PCS802S/B works, backlight is on.So is the optocoupler dead?

        Comment

        • seve91
          Senior Member
          • Oct 2013
          • 75
          • Italy

          #64
          Re: Samsung 32" power supply BN44-0351B no backlight

          Originally posted by dskall
          They look yellow to me. Look at color temp charts. Higher temps are bluer lower temps are yellow
          yes, exactly! I bought 5700k as you said, but looks like yellow.
          Just bought 6500k...hope to solve the issue.
          Anyway the power supply is now working, backlight also...maybe it was a bad soldering problem in the optocoupler.

          Comment

          • diif
            Badcaps Legend
            • Feb 2014
            • 6978
            • England

            #65
            Re: Samsung 32" power supply BN44-0351B no backlight

            Where did you get the LEDs from ?
            Apart from the colour difference they also seem brighter.

            Comment

            • seve91
              Senior Member
              • Oct 2013
              • 75
              • Italy

              #66
              Re: Samsung 32" power supply BN44-0351B no backlight

              Originally posted by diif
              Where did you get the LEDs from ?
              Apart from the colour difference they also seem brighter.
              yes, exactly. Also the pinout is different. Can't find the exact model of LED installed in the backlight bar. I bought them from ebay.

              http://www.ebay.it/itm/10-pieces-OSR...53.m2749.l2649

              Now i've just bought these 6500k:
              http://www.ebay.it/itm/4x-10x-LUW-JD...53.m2749.l2649

              Comment

              • diif
                Badcaps Legend
                • Feb 2014
                • 6978
                • England

                #67
                Re: Samsung 32" power supply BN44-0351B no backlight

                I would think they are using their own LEDs in their TVs. Perhaps something like the LM561B.
                Attached Files

                Comment

                • dskall
                  Badcaps Legend
                  • Oct 2016
                  • 2905
                  • usa

                  #68
                  Re: Samsung 32" power supply BN44-0351B no backlight

                  Well again look at color chart. https://en.wikipedia.org/wiki/Color_temperature
                  Higher temps are bluer. Trouble is just because they list them as certain temp doesn't mean they are. If you get actual 5700k they will be yellow. I would contact seller and tell them you did not get right temp leds.
                  I assume no responsibility for any stupid suggestions I might post.

                  Comment

                  • seve91
                    Senior Member
                    • Oct 2013
                    • 75
                    • Italy

                    #69
                    Re: Samsung 32" power supply BN44-0351B no backlight

                    Originally posted by diif
                    I would think they are using their own LEDs in their TVs. Perhaps something like the LM561B.
                    Originally posted by dskall
                    Well again look at color chart. https://en.wikipedia.org/wiki/Color_temperature
                    Higher temps are bluer. Trouble is just because they list them as certain temp doesn't mean they are. If you get actual 5700k they will be yellow. I would contact seller and tell them you did not get right temp leds.
                    yes but almost impossible to find. Hope 6500k leds i've just bought got the right temp

                    Comment

                    • diif
                      Badcaps Legend
                      • Feb 2014
                      • 6978
                      • England

                      #70
                      Re: Samsung 32" power supply BN44-0351B no backlight

                      Originally posted by seve91
                      yes but almost impossible to find. Hope 6500k leds i've just bought got the right temp
                      Not really.
                      it.rs-online.com/web/c/display-e-optoelettronica/led-e-accessori/led-visibili/?searchTerm=LM561B

                      Not data sheet but shows a picture of the bottom of the LED not in the data sheet.
                      Attached Files
                      Last edited by diif; 09-04-2017, 01:43 PM. Reason: added datasheet

                      Comment

                      • seve91
                        Senior Member
                        • Oct 2013
                        • 75
                        • Italy

                        #71
                        Re: Samsung 32" power supply BN44-0351B no backlight

                        ok i've bought these leds, 14.62€ includes shipping. we will see if they got same temperature

                        Comment

                        • JamesPereira
                          New Member
                          • Feb 2018
                          • 1
                          • Portugal

                          #72
                          Re: Samsung 32" power supply BN44-0351B no backlight

                          I have the same problem in your model tv, i dont have backlight here is the pcs802s/b? Can you show me by picture? Thanks a lot

                          Comment

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