Samsung UN55H8000AFXZA No Backlight, LED Strips OK

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  • alfredomfr1
    Badcaps Veteran
    • Oct 2014
    • 318
    • usa

    #21
    Re: Samsung UN55H8000AFXZA No Backlight, LED Strips OK

    Ic9951
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    • R_J
      Badcaps Legend
      • Jun 2012
      • 9558
      • Canada

      #22
      Re: Samsung UN55H8000AFXZA No Backlight, LED Strips OK

      Originally posted by alfredomfr1
      Q9951 and Q9952 OK, R9988 and R9958 OK
      IC 9951: NCP1034DG
      10k R9972 and R9973 are OK when tested out but R9973 only read 68 ohm in the circuit. All components on the picture are OK
      If you are measuring 68Ω across Q9951 G~S I suspect the drive ic is bad. If you look at the voltages on the ic you will see pins 10 & 11 are both 10v, this suggests to me that the (internal fet) between Vs and HDrv is shorted D~S

      The ic's pin 10 connects to one side of R9987 (68Ω) the other side of the resistor connects to Q9951 source, so when you measure across R9973 you are actually reading R9987
      Last edited by R_J; 03-17-2020, 04:15 PM.

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      • alfredomfr1
        Badcaps Veteran
        • Oct 2014
        • 318
        • usa

        #23
        Re: Samsung UN55H8000AFXZA No Backlight, LED Strips OK

        R_J You are totally right. IC replaced, TV working !!!.
        Thanks to You, budm and Vinceroger69 for the appreciate help.

        Comment

        • R_J
          Badcaps Legend
          • Jun 2012
          • 9558
          • Canada

          #24
          Re: Samsung UN55H8000AFXZA No Backlight, LED Strips OK

          Good to here, thanks for letting us know.

          Comment

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