Samsung UE40MU61 no red led but backlight

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  • kevvort
    Member
    • May 2023
    • 10
    • Italy

    #1

    Samsung UE40MU61 no red led but backlight

    Hi all!
    I've a Samsung UE40MU61 that's not showing the red led when it's in stand-by nor turns on.
    I diagnosed the power board and looks like it's fine + if I disconnect the main board all the panel backlights turn on so I suppose, based on what I've found, that the power board should be ok.
    Then I moved to the main board BN41-02568B and after some googling I've found this forum where a lot of people reported that the issue could be in the FW contained in the W25Q40CL chip.
    I got my reader and dumped it but it doesn't look like it's corrupted because there's data in the first 0x1000 addresses.

    I also checked the joystick and voltages are ok but the red led voltage is totally missing.

    Do you have any tip for me? For being sure I'll attach my dumped firmware.

    Thanks a lot
    Attached Files
  • lotas
    Badcaps Legend
    • Jan 2016
    • 4578
    • Russia

    #2
    Re: Samsung UE40MU61 no red led but backlight

    What a strange Dump you have, it looks like a Dump from T-con (25Q80), you didn’t accidentally mix up the chips.

    Comment

    • kevvort
      Member
      • May 2023
      • 10
      • Italy

      #3
      Re: Samsung UE40MU61 no red led but backlight

      You were absolutely right, my bad... here as attachment my 1604 dump with a lot of FF in the first areas

      Just for curiosity: do you just restore the first 0x1000 addresses or do you do something else?
      Attached Files

      Comment

      • lotas
        Badcaps Legend
        • Jan 2016
        • 4578
        • Russia

        #4
        Re: Samsung UE40MU61 no red led but backlight

        Try it, do not forget about the Status Register, but I restore the "header" with the correct version of the software.
        Attached Files

        Comment

        • kevvort
          Member
          • May 2023
          • 10
          • Italy

          #5
          Re: Samsung UE40MU61 no red led but backlight

          Originally posted by lotas
          Try it, do not forget about the Status Register, but I restore the "header" with the correct version of the software.
          Got it and ok about the status register, I did it.
          Now the red led is on, I can turn on the TV but I've a black screen with backlight, then looks like it bootloops.

          Any tips?

          Comment

          • lotas
            Badcaps Legend
            • Jan 2016
            • 4578
            • Russia

            #6
            Re: Samsung UE40MU61 no red led but backlight

            Well, maybe they damaged or incorrectly, somehow they recorded a dump in 25Q80 (you didn’t do anything with it?).

            Comment

            • kevvort
              Member
              • May 2023
              • 10
              • Italy

              #7
              Re: Samsung UE40MU61 no red led but backlight

              Originally posted by lotas
              Well, maybe they damaged or incorrectly, somehow they recorded a dump in 25Q80 (you didn't do anything with it?).
              Unfortunately yes, I tried to restore the content but it's a 25Q80 and I dumped it as a 25Q40 so I miss half the data

              Are IC1604 and 1603 coupled? I think I can at least try to find a IC1603 dump and merge the first half with mine but I need to be very lucky...

              Do you think it's the best thing I can do other than beating my head?

              Comment

              • lotas
                Badcaps Legend
                • Jan 2016
                • 4578
                • Russia

                #8
                Re: Samsung UE40MU61 no red led but backlight

                Now you need to look for exactly the same dump 25q80 that was originally, it contains all the settings and data of your panel, what is the number of your panel?
                And the full model of the TV itself and the motherboard number BN94-xxxxx?
                Last edited by lotas; 05-15-2023, 04:45 PM.

                Comment

                • lotas
                  Badcaps Legend
                  • Jan 2016
                  • 4578
                  • Russia

                  #9
                  Re: Samsung UE40MU61 no red led but backlight

                  Originally posted by kevvort
                  Are IC1604 and 1603 coupled? I think I can at least try to find a IC1603 dump and merge the first half with mine but I need to be very lucky...
                  These are completely different dumps, and each is responsible for his own, and there is nothing to combine in them, there is no need to cross.

                  Comment

                  • Diah
                    Badcaps Legend
                    • Feb 2013
                    • 6363
                    • Germany

                    #10
                    Re: Samsung UE40MU61 no red led but backlight

                    since TV go to STB and turn on... all other issue can be solved by service menu call from STB

                    Comment

                    • kevvort
                      Member
                      • May 2023
                      • 10
                      • Italy

                      #11
                      Re: Samsung UE40MU61 no red led but backlight

                      TV full model: UE40MU6120KXZT
                      Board: Code: BN41-02568B
                      MODEL: BN41-02568B
                      MOEDL: KANT_M_BUILT_IN

                      So every dump should work or are there any keys that should match with other components?

                      Comment

                      • lotas
                        Badcaps Legend
                        • Jan 2016
                        • 4578
                        • Russia

                        #12
                        Re: Samsung UE40MU61 no red led but backlight

                        Originally posted by Diah
                        since TV go to STB and turn on... all other issue can be solved by service menu call from STB
                        What is the service menu if it completely killed the dump T-CON.

                        Comment

                        • lotas
                          Badcaps Legend
                          • Jan 2016
                          • 4578
                          • Russia

                          #13
                          Re: Samsung UE40MU61 no red led but backlight

                          Originally posted by kevvort
                          TV full model: UE40MU6120KXZT
                          Board: Code: BN41-02568B
                          MODEL: BN41-02568B
                          MOEDL: KANT_M_BUILT_IN

                          So every dump should work or are there any keys that should match with other components?
                          I need the number not BN41-xxxx, but the number BN94-xxxxx (it is on a white tag pasted on the motherboard), and I asked for the number, panel (matrix) model.

                          Comment

                          • Diah
                            Badcaps Legend
                            • Feb 2013
                            • 6363
                            • Germany

                            #14
                            Re: Samsung UE40MU61 no red led but backlight

                            Originally posted by lotas
                            What is the service menu if it completely killed the dump T-CON.
                            T-CON are for freq rate displaying.. S;M are simple rate don't depend on any high resolution T-CON support

                            Comment

                            • lotas
                              Badcaps Legend
                              • Jan 2016
                              • 4578
                              • Russia

                              #15
                              Re: Samsung UE40MU61 no red led but backlight

                              Originally posted by Diah
                              T-CON are for freq rate displaying.. S;M are simple rate don't depend on any high resolution T-CON support
                              In these models, if the dump T-CON (25Q80) is damaged, then there will be no image, only the backlight!
                              Last edited by lotas; 05-15-2023, 05:45 PM.

                              Comment

                              • lotas
                                Badcaps Legend
                                • Jan 2016
                                • 4578
                                • Russia

                                #16
                                Re: Samsung UE40MU61 no red led but backlight

                                kevvort try dump 25Q80
                                Attached Files

                                Comment

                                • Davi.p
                                  Hobbist Tech
                                  • Sep 2009
                                  • 4316
                                  • Italy - Milan

                                  #17
                                  Re: Samsung UE40MU61 no red led but backlight

                                  Hi, can you explain to me better? You have read the tcon memory as a 25Q40, after this you noticed was the wrong memory, so you haven't write any thing on that right? If this is the case you probably has a fault in the panel..

                                  Comment

                                  • kevvort
                                    Member
                                    • May 2023
                                    • 10
                                    • Italy

                                    #18
                                    Re: Samsung UE40MU61 no red led but backlight

                                    Originally posted by lotas
                                    kevvort try dump 25Q80
                                    Thank you Lotas, it worked!
                                    Now I'll test deeper if everything is fine but I think I'm ok.

                                    Comment

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