Un50mu6070 Mainboard issue

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  • petersor
    Member
    • Feb 2020
    • 43
    • United States

    #121
    Got it. Thanks for the clarification. I'll give that a try today.

    Rich

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    • petersor
      Member
      • Feb 2020
      • 43
      • United States

      #122
      No shorts on the data lines. With the jumper in place, the behavior of the TV is the same with both LVDS connected, left connected only, right connected only and both disconnected . . . 1-2 second flash of the standby light with about 15 ~ 18 seconds between flashes. Same as before.

      Rich

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      • lotas
        Badcaps Legend
        • Jan 2016
        • 4451
        • Russia

        #123
        Disconnect the wi-fi module, also check these contacts for resistance to ground (LAN).
        Attached Files

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        • petersor
          Member
          • Feb 2020
          • 43
          • United States

          #124
          No change with WiFi disconnected - The jumper is still installed on the LVDS - should I remove that?

          The LAN IC (0524P) doesn't have any shorts (except the center pin 3 which is the ground pin . . .

          Comment

          • petersor
            Member
            • Feb 2020
            • 43
            • United States

            #125
            I hooked a 13V power supply up to the main board and measured voltages on the coils - some are steady and some drop to 0 as the board power cycles. . . . The board was not connected to the TV when I took the measurements. Not sure if this is helpful



            Click image for larger version  Name:	Coil Voltages.jpg Views:	0 Size:	3.12 MB ID:	3570111

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            • petersor
              Member
              • Feb 2020
              • 43
              • United States

              #126
              One other possible clue - The audio amplifier IC (TAS5749M) has a warm, not hot, spot in one corner . . . .that comes and goes as the board powers up and down.

              Click image for larger version

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              • petersor
                Member
                • Feb 2020
                • 43
                • United States

                #127
                lotas - Anything else I can try on this board or is it unrepairable?

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                • lotas
                  Badcaps Legend
                  • Jan 2016
                  • 4451
                  • Russia

                  #128
                  Check with this table (voltage / resistance), the problem may be in the eeprom 24C512 firmware or in the eMMC, maybe in the processor itself, I'll dump dump 25c512 for diagnostics...
                  Only your dump (24C512) must be saved.
                  Attached Files
                  Last edited by lotas; 02-14-2025, 10:16 AM.

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                  • petersor
                    Member
                    • Feb 2020
                    • 43
                    • United States

                    #129
                    Thanks. I'll take a look tomorrow.

                    Comment

                    • petersor
                      Member
                      • Feb 2020
                      • 43
                      • United States

                      #130
                      here are the voltage and resistance reading I measured:

                      Click image for larger version

Name:	Voltage & Resistance Results.jpg
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                      • lotas
                        Badcaps Legend
                        • Jan 2016
                        • 4451
                        • Russia

                        #131
                        The measurements were made without a jumper (no t-con output voltages)?

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                        • petersor
                          Member
                          • Feb 2020
                          • 43
                          • United States

                          #132
                          Correct - no jumper.

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                          • lotas
                            Badcaps Legend
                            • Jan 2016
                            • 4451
                            • Russia

                            #133

                            It is necessary with a jumper to see the remaining voltages.​

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                            • petersor
                              Member
                              • Feb 2020
                              • 43
                              • United States

                              #134
                              OK. I'll add the jumper back and test again. Thanks for your patience.

                              Comment

                              • petersor
                                Member
                                • Feb 2020
                                • 43
                                • United States

                                #135
                                Voltages and resistances are the same with the jumper in place.

                                Click image for larger version

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                                Attached Files

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                                • Diah
                                  Badcaps Legend
                                  • Feb 2013
                                  • 6335
                                  • Germany

                                  #136
                                  from yours measurement and test with Jumper and with out, it tell you have cut off of the I2C from the SoC. its 99% BGA. need to refllow

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                                  • lotas
                                    Badcaps Legend
                                    • Jan 2016
                                    • 4451
                                    • Russia

                                    #137
                                    What panel do you have, number CY-xxxxxx?

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                                    • lotas
                                      Badcaps Legend
                                      • Jan 2016
                                      • 4451
                                      • Russia

                                      #138
                                      Originally posted by petersor
                                      Voltages and resistances are the same with the jumper in place.

                                      Click image for larger version

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ID:	3573307
                                      This chassis also had problems with the crystal falling off the substrate, remove the radiator and blow on the crystal with a soldering station for 30 seconds at a temperature of 200-250C.

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                                      • petersor
                                        Member
                                        • Feb 2020
                                        • 43
                                        • United States

                                        #139
                                        I'll check the panel number when I get back to the house tomorrow. I'll try reflowing the crystals first and if that doesn't help, I'll try the main processor . . .

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                                        • petersor
                                          Member
                                          • Feb 2020
                                          • 43
                                          • United States

                                          #140
                                          Panel number is CY-GK050HGAV5H

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