Before I Tear Into This Panel...

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  • mmartell
    Badcaps Legend
    • Oct 2013
    • 3189
    • Canada
    #1

    Before I Tear Into This Panel...

    Is there a way to tell if the LED driver circuits are working properly ?

    It's a Samsung UN46D7000 which works (when it's not rebooting) because the bottom quarter of the screen is darker than the rest of the panel. Of course I suspect bad led(s) but would like to be prudent before cracking this thing open.

    So what measurements and how to take them ?
    Tags: None
    • mmartell
      Badcaps Legend
      • Oct 2013
      • 3189
      • Canada
      #2
      Re: Before I Tear Into This Panel...

      Sorry, pic of the led connectors coming shortly, have to get my son off the bus

        Comment

        • mmartell
          Badcaps Legend
          • Oct 2013
          • 3189
          • Canada
          #3
          Re: Before I Tear Into This Panel...

          Some pics...
          Attached Files

            Comment

            • mmartell
              Badcaps Legend
              • Oct 2013
              • 3189
              • Canada
              #4
              Re: Before I Tear Into This Panel...

              I've measured the voltages at the four long electrolytic caps in the first pic while the set was on and stable. The top three had about 147v on them and stable. The bottom one (as seen on the pic) was fluctuating around 295v! plus or minus 5v.

              Any input on what I'm seeing here ?

                Comment

                • freakaftr8
                  Badcaps Legend
                  • Oct 2012
                  • 3743
                  • USA
                  #5
                  Re: Before I Tear Into This Panel...

                  This may be because its connected to the output of the dead string of leds so there is no load on the circuit.

                  May be normal.
                  Did I leave the soldering iron on?

                    Comment

                    • budm
                      Badcaps Legend
                      • Feb 2010
                      • 40746
                      • USA
                      #6
                      Re: Before I Tear Into This Panel...

                      Originally posted by freakaftr8
                      this may be because its connected to the output of the dead string of leds so there is no load on the circuit.

                      May be normal.
                      +1, more likely open LED string.
                      Never stop learning
                      Basic LCD TV and Monitor troubleshooting guides.
                      http://www.badcaps.net/forum/showthr...956#post305956

                      Voltage Regulator (LDO) testing:
                      http://www.badcaps.net/forum/showthr...999#post300999

                      Inverter testing using old CFL:
                      http://www.badcaps.net/forum/showthr...er+testing+cfl

                      Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                      http://s807.photobucket.com/user/budm/library/

                      TV Factory reset codes listing:
                      http://www.badcaps.net/forum/showthread.php?t=24809

                        Comment

                        • mmartell
                          Badcaps Legend
                          • Oct 2013
                          • 3189
                          • Canada
                          #7
                          Re: Before I Tear Into This Panel...

                          Ok guys that's good enough for me. Next step is to open it up and try to be gentle

                            Comment

                            • mmartell
                              Badcaps Legend
                              • Oct 2013
                              • 3189
                              • Canada
                              #8
                              Re: Before I Tear Into This Panel...

                              Okay so after a few hours this one is repaired. How ?

                              This is what they mean by "Labour" as in Parts and Labour. After getting the back off and peeling the last panel (diffuser?) back slightly to see the led connector it seemed a little crooked. Sure enough when I pushed in on the one side it "clicked". I plugged it in right away and was presented with solid even lighting.

                              The connector pic is after it was seated and just for documentation. The connector in question is for the right side strip. One vertical strip per side, and I will note it is a different assembly than those used in the D6000 I disassembled previously.
                              Attached Files

                                Comment

                                • freakaftr8
                                  Badcaps Legend
                                  • Oct 2012
                                  • 3743
                                  • USA
                                  #9
                                  Re: Before I Tear Into This Panel...

                                  That's awesome when its a happy ending. Lol
                                  Did I leave the soldering iron on?

                                    Comment

                                    • budm
                                      Badcaps Legend
                                      • Feb 2010
                                      • 40746
                                      • USA
                                      #10
                                      Re: Before I Tear Into This Panel...

                                      Great! So the picture of the connector, is it located inside the panel?
                                      Last edited by budm; 02-28-2015, 12:45 AM.
                                      Never stop learning
                                      Basic LCD TV and Monitor troubleshooting guides.
                                      http://www.badcaps.net/forum/showthr...956#post305956

                                      Voltage Regulator (LDO) testing:
                                      http://www.badcaps.net/forum/showthr...999#post300999

                                      Inverter testing using old CFL:
                                      http://www.badcaps.net/forum/showthr...er+testing+cfl

                                      Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                                      http://s807.photobucket.com/user/budm/library/

                                      TV Factory reset codes listing:
                                      http://www.badcaps.net/forum/showthread.php?t=24809

                                        Comment

                                        • freakaftr8
                                          Badcaps Legend
                                          • Oct 2012
                                          • 3743
                                          • USA
                                          #11
                                          Re: Before I Tear Into This Panel...

                                          This setup is identical to the UN40ES6100 I repaired a few months ago. That one had a bad led driver but I got into the panel too have a look anyway.
                                          Did I leave the soldering iron on?

                                            Comment

                                            • mmartell
                                              Badcaps Legend
                                              • Oct 2013
                                              • 3189
                                              • Canada
                                              #12
                                              Re: Before I Tear Into This Panel...

                                              Originally posted by budm
                                              Great! So the picture of the connector, is it located inside the panel?
                                              Yes bud, required a complete teardown. The backlight assembly had the diffuser or reflector glued to it so it needed to be peeled back slightly to gain access to the led strip connector behind it.

                                                Comment

                                                • mmartell
                                                  Badcaps Legend
                                                  • Oct 2013
                                                  • 3189
                                                  • Canada
                                                  #13
                                                  Re: Before I Tear Into This Panel...

                                                  Originally posted by freakaftr8
                                                  This setup is identical to the UN40ES6100 I repaired a few months ago. That one had a bad led driver but I got into the panel too have a look anyway.
                                                  Hah you are very adventurous, I would only do this as a last resort. Aside from breaking the lcd panel itself I'm worried about marking up the layers so fingerprints and dust etc is visible after reassembly. I used two fresh garbage bags to cover assembly while I was working on the backlight.

                                                    Comment

                                                    • freakaftr8
                                                      Badcaps Legend
                                                      • Oct 2012
                                                      • 3743
                                                      • USA
                                                      #14
                                                      Re: Before I Tear Into This Panel...

                                                      THats a good idea! I use the same thing. Lol
                                                      Did I leave the soldering iron on?

                                                        Comment

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