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Samsung LN32A450C1D - With partial picture

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    Samsung LN32A450C1D - With partial picture

    As you can see in the picture, I have a Samsung LN32A450C1D that has a partial picture.

    The set doesn't appear to have any power issues. I'll re-cap the power board(Samwha caps) after I get the main issue resolved.

    TCON fuse shows 11.91 on both sides
    Sounds works

    Voltage Regulators are listed below - I not sure how to tell if one of these is bad.

    location -IC1001
    SPX1587AT
    0819LC
    pin 1= 1.456
    pin 2= 2.713
    pin 3= 4.91


    location -IC1002
    17-33
    0808AG
    pin 1=-.006
    pin 2= 3.276
    pin 3= 4.92


    location -IC1003
    SPX1587AT
    0819LC
    pin 1= 2.066
    pin 2= 3.323
    pin 3= 5.26


    location -IC1004
    RT9183
    12PGFAD11W
    pin 1= -.005
    pin 2= 1.181
    pin 3= 3.319

    location -IC1006
    1117
    0811HG
    pin 1= 1.255
    pin 2= 2.497
    pin 3= 5.25

    location -IC1008
    78M09A
    J7 1A
    pin 1= 12.06
    pin 2= -.006
    pin 3= 9.03

    location -IC1009
    KIA
    7805AF
    814
    pin 1= 9.03
    pin 2= -.006
    pin 3= 5.02
    Attached Files

    #2
    Re: Samsung LN32A450C1D - With partial picture

    Originally posted by ceconomon View Post
    Voltage Regulators are listed below - I not sure how to tell if one of these is bad.
    The part number/datasheet tells you the expected output voltage. If it has a suffix like -33, that means the output voltage should be 3.3V DC +/- 1% (some datasheets specify 2%).

    If there is no suffix, then it is an adjustable regulator and it should be pin 1 + 1.25V for the output of pin 2.

    location -IC1004
    RT9183
    12PGFAD11W
    pin 1= -.005
    pin 2= 1.181
    pin 3= 3.319
    IC1004 is suspect. At 1.181, it is 5.52% ((1.25-1.181)/1.25) out of spec as the output should be 1.25V DC.

    By the way, you should never have a negative voltage reading if you are using the proper ground. This implies your multimeter might be out of calibration.

    With your multimeter set to DC V, when you touch the two probes together, it should read 0.000V.
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      #3
      Re: Samsung LN32A450C1D - With partial picture

      I'll pull it off and test it using the technique you taught me in a previous post.

      Since this is a fix voltage regulator, I won't need to use any resistors. I'll be connecting 2 AA batteries together and checking the output on PIN2.

      Comment


        #4
        Re: Samsung LN32A450C1D - With partial picture

        Something doesn't seem right with my testing method or I don't fully understand how I should be testing the regulator.

        2xAA batteries=~3.0V

        PIN1 connected to Negative (GND)
        PIN3 connected to Positive

        Measure
        PIN1 to PIN3=3.057V
        PIN1 to PIN2=1.466V

        Shouldn't PIN2=1.2V per the spec sheet? (RT9183 12PGFAD11W)

        Comment


          #5
          Re: Samsung LN32A450C1D - With partial picture

          Originally posted by ceconomon View Post
          Shouldn't PIN2=1.2V per the spec sheet? (RT9183 12PGFAD11W)
          Oops, my bad.

          I didn't see the 2nd line in my initial scan of your results. You are correct it is a fixed 1.2V regulator so 1.181 is a good reading.
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            #6
            Re: Samsung LN32A450C1D - With partial picture

            Originally posted by ceconomon View Post
            Something doesn't seem right with my testing method or I don't fully understand how I should be testing the regulator.

            2xAA batteries=~3.0V

            PIN1 connected to Negative (GND)
            PIN3 connected to Positive

            Measure
            PIN1 to PIN3=3.057V
            PIN1 to PIN2=1.466V

            Shouldn't PIN2=1.2V per the spec sheet? (RT9183 12PGFAD11W)
            The datasheet lists two types of SOT-223 packages. Depending on which you have, VOUT could be pin 2 or pin 3.

            And yes, the output should be 1.2. If pin 2 is truly 1.466V, then that is a problem.
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              #7
              Re: Samsung LN32A450C1D - With partial picture

              It looks like you have the F-Type according to the datasheet from your initial readings.

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                #8
                Re: Samsung LN32A450C1D - With partial picture

                Did you measure the voltage regulator on the t-con board? There is one obvious one and maybe a DC-DC converter on the board?
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                  #9
                  Re: Samsung LN32A450C1D - With partial picture

                  Have you unplugged the lvds cable cleaned and reseated it?

                  Try gentle pressure on the tab bonds on the panel.
                  Please upload pictures using attachment function when ask for help on the repair
                  http://www.badcaps.net/forum/showthread.php?t=39740

                  Comment


                    #10
                    Re: Samsung LN32A450C1D - With partial picture

                    I measured the voltage several times with my testing rig and it was the same each time. I reattached the regulator to the main board and the readings were the same as before it was removed.

                    I gleened a little bit of knowledge from that excercise. I'm still not comfortable with the readings from the test.

                    Originally posted by retiredcaps View Post
                    Did you measure the voltage regulator on the t-con board? There is one obvious one and maybe a DC-DC converter on the board?
                    Here are the measurements from the regulator on the t-con board.

                    I can't seem to find any specs on this one.

                    K
                    A1718
                    Y 803

                    1=2.634
                    2=1.218
                    3=3.3.01


                    I took some better pictures of the TCON. I'm not sure about the second part you mentioned. I outlined two parts. The one listed aboved and :

                    24C64WP
                    K807P
                    Which appears to be an EPROM.


                    Originally posted by selldoor View Post
                    Have you unplugged the lvds cable cleaned and reseated it?

                    Try gentle pressure on the tab bonds on the panel.
                    The cable has been cleaned and reseated and there is no change in the picture.

                    I tore the panel down to where I could get to the tabs. I know now why it was so hard to get that metal trim off around the panel. If I'm not mistaken, that's piece of weather stripping. That means someone has tried to repair this set before. I see no re-work on any of the boards.

                    I carefully removed the weather stripping and applied light pressure on the tabs. The picture did not change when pressure was applied. I am hoping this rules out a tab bonding issue.
                    Attached Files

                    Comment


                      #11
                      Re: Samsung LN32A450C1D - With partial picture

                      Originally posted by ceconomon View Post
                      I can't seem to find any specs on this one.

                      K
                      A1718
                      Y 803

                      1=2.634
                      2=1.218
                      3=3.3.01
                      It looks like a PNP transistor. I don't know if the voltages are good or not, but at least it is not shorted otherwise the voltage readings would be the same.

                      http://pdf1.alldatasheet.com/datashe.../KTA1718D.html
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                        #12
                        Re: Samsung LN32A450C1D - With partial picture

                        Does anyone else have any input on this set?

                        I'm not sure if I have a bad panel or t-con at this point. I don't appear to have a tab bonding issue, so I'm leaning toward the t-con.

                        Comment


                          #13
                          Re: Samsung LN32A450C1D - With partial picture

                          If you can get a tcon for cheap (say $20), then it might be worth a try.

                          The front page on my local warmart flyer shows a Seiki 40 inch LCD HDTV (1080p) for $298.

                          I present the above pricing info just to give you an idea how much you should spend trying to fix a 32 inch tv.
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