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DSE GE6987 LCD TV main board (303C3393073) - DDR SDRAM voltage

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    DSE GE6987 LCD TV main board (303C3393073) - DDR SDRAM voltage

    This board is almost identical to the Haier 55E3500, and in both controllers, DDR SDRAM is integrated.
    When connected to a power supply and LCD controller tester, a brief "Loading" message appeared before the picture snowed out, but it did start up OK under unknown circumstances.
    An analysis of the circuit revealed that the DDR 1.8V regulator was set for 1.5V (270R between regulator Adjust-Output and 56R between regulator Adjust-GND; 120R between Adjust-GND sets output voltage to 1.8V); even though the Haier circuit uses the MSD3393 (ATSC) as its controller, the GE6987 uses the MSD6306 (DVB) with the same pinout.
    Searching for sets which used the MSD6306 (and a block diagram of this IC) revealed that some use a 1.5V DDR voltage while others used 1.8V; the absolute maximum voltage for DDR3 (1.5V +/- 0.075V) SDRAM is 1.975V, so changing the voltage of the DDR regulator to 1.8V with a 240R resistor added between Adjust-Output (even though there was a minor risk of catastrophic failure) resulted in consistent startup of this board without excessive current draw.
    My first choice in quality Japanese electrolytics is Nippon Chemi-Con, which has been in business since 1931... the quality of electronics is dependent on the quality of the electrolytics.

    #2
    Re: DSE GE6987 LCD TV main board (303C3393073) - DDR SDRAM voltage

    May I ask?

    What is the difference between MSD6306 and MSD3393LUM? is that because V-Chip Control or integrated Internet or Android system?

    Study MSD3393LUM
    https://www.badcaps.net/forum/showthread.php?t=60902
    Last edited by capwizard; 01-12-2019, 04:33 AM.

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      #3
      Re: DSE GE6987 LCD TV main board (303C3393073) - DDR SDRAM voltage

      Originally posted by capwizard View Post
      What is the difference between MSD6306 and MSD3393LUM?https://www.badcaps.net/forum/showthread.php?t=60902
      The MSD6306 is DVB while the MSD3393 is ATSC.
      My first choice in quality Japanese electrolytics is Nippon Chemi-Con, which has been in business since 1931... the quality of electronics is dependent on the quality of the electrolytics.

      Comment


        #4
        Re: DSE GE6987 LCD TV main board (303C3393073) - DDR SDRAM voltage

        Originally posted by japlytic View Post
        The MSD6306 is DVB while the MSD3393 is ATSC.
        oh Thank you.

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