Emerson LTDN42V68US Red Standby Only

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  • fharris1977
    Senior Member
    • May 2017
    • 132
    • United States
    #1

    Emerson LTDN42V68US Red Standby Only

    Hello. I have an Emerson lcd set and it won't turn on with remote or button board on set. It shows a solid red standby led. I suspected the eeprom(N10) so I replaced it but still same results. I still suspect the main board as the culprit, please correct me if I'm wrong. If it is the main board could antone direct me to repairing it? Thanks in advance.
    Attached Files
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    • nomoresonys
      Badcaps Legend
      • Jan 2013
      • 12128
      • U.S.
      #2
      Re: Emerson LTDN42V68US Red Standby Only

      Try test #3 below, try to do it just as directed, pin number, pin description, voltage both off/standby and when power is applied.

        Comment

        • fharris1977
          Senior Member
          • May 2017
          • 132
          • United States
          #3
          Re: Emerson LTDN42V68US Red Standby Only

          Normal Power Applied

          1.88v 1.89v (1)m5v
          1.89v 1.89v (2)m5v
          0.00v 0.00v (3)gnd
          0.00v 0.00v (4)gnd
          0.01v 0.01v (5)sw
          1.87v 1.86v (6)brt
          0.00v 0.00v (7)gnd
          4.20v 4.20v (8)12v
          4.21v 4.20v (9)12v
          5.267v 5.267v (10)s5v
          5.267v 5.267v (11)s5v
          3.919v 3.919v (12)stb
          0.00v 0.00v (13)gnd
          0.00v 0.00v (14)gnd

          12.42v 12.45v (15)12v
          12.42v 12.45v (16)12v
          0.00v 0.00v (17)gnd
          0.00v 0.00v (18)gnd
          4.33v 4.35v (19)12v
          0.001v 0.001v (20)gnd
          2.045v 2.055v (21)m5v
          0.001v 0.001v (22)gnd
          0.001v 0.001v (23)gnd
          2.055v 2.065v (24)m5v
          2.065v 2.075v (25)m5v
          0.001v 0.001v (26)gnd
          0.001v 0.001v (27)gnd
          Attached Files

            Comment

            • R_J
              Badcaps Legend
              • Jun 2012
              • 9535
              • Canada
              #4
              Re: Emerson LTDN42V68US Red Standby Only

              I see at least one bad cap C929 and maybe C945, 2200µf/25v but these are for the +12v supply. The M5v is low but that voltage is switched by V924 so check that you have +5 volts on jumper wire W914. If the +5volts is ok, try changing C937 (1µf/50v) If the +5v is low it could be that C935, C936 & C938 are also bad
              Last edited by R_J; 06-23-2020, 05:57 PM.

                Comment

                • fharris1977
                  Senior Member
                  • May 2017
                  • 132
                  • United States
                  #5
                  Re: Emerson LTDN42V68US Red Standby Only

                  Originally posted by nomoresonys
                  Try test #3 below, try to do it just as directed, pin number, pin description, voltage both off/standby and when power is applied.
                  Normal Power Applied

                  1.88v 1.89v (1)m5v
                  1.89v 1.89v (2)m5v
                  0.00v 0.00v (3)gnd
                  0.00v 0.00v (4)gnd
                  0.01v 0.01v (5)sw
                  1.87v 1.86v (6)brt
                  0.00v 0.00v (7)gnd
                  4.20v 4.20v (8)12v
                  4.21v 4.20v (9)12v
                  5.267v 5.267v (10)s5v
                  5.267v 5.267v (11)s5v
                  3.919v 3.919v (12)stb
                  0.00v 0.00v (13)gnd
                  0.00v 0.00v (14)gnd

                  12.42v 12.45v (15)12v
                  12.42v 12.45v (16)12v
                  0.00v 0.00v (17)gnd
                  0.00v 0.00v (18)gnd
                  4.33v 4.35v (19)12v
                  0.001v 0.001v (20)gnd
                  2.045v 2.055v (21)m5v
                  0.001v 0.001v (22)gnd
                  0.001v 0.001v (23)gnd
                  2.055v 2.065v (24)m5v
                  2.065v 2.075v (25)m5v
                  0.001v 0.001v (26)gnd
                  0.001v 0.001v (27)gnd

                    Comment

                    • nomoresonys
                      Badcaps Legend
                      • Jan 2013
                      • 12128
                      • U.S.
                      #6
                      Re: Emerson LTDN42V68US Red Standby Only

                      Yep, switch out at least that bulging cap, then try it, suppose if you wanted to be a little more proactive you could change out all the caps in that area, some folks would change out all the electrolytic caps on the board.
                      Last edited by nomoresonys; 06-24-2020, 02:06 PM.

                        Comment

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