42" Vizio No Picture has Backlight

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  • MisterD
    Badcaps Veteran
    • Oct 2012
    • 668
    • United States

    #1

    42" Vizio No Picture has Backlight

    This is a newer LED/LCD TV, has LED for Backlighting and an LCD Display Panel.
    It does power on but has no display, has only a blank grayish screen with no video, I tried hooking up a dvd player as a source but since I can not see any images on the tv screen I can't tell what input mode is selected. with this set is was easier to measure voltages on the small fuses on both the Mainboard and T-Con Board. instead of measuring at the power supply connectors and taking a chance on the meter probe slipping and shorting out.
    It has all dc voltages present, 5 volts, 12 volts and 18 volts. I measured these on both sides of the fuses to ensure the fuses are good as well as voltages being present. I noticed that the processor under the metal shield on the mainboard is generating some heat so hopefully it is working, but the heat sink on the T-Con stays cool even after leaving the set on for over 1 hour. I removed and reinstalled the T-Con board therefore re-seated attached ribbon cables and visually inspected the board. At this point I think the T-Con board has failed and is causing the problem, I do have another posting on this set but could not edit the heading or delete the post and I felt like the heading was misleading. Model Vizio XVT3D424SV. please reply back, your help is appreciated. Thanks!
  • XmouseX
    Senior Member
    • Aug 2011
    • 158
    • US

    #2
    Re: 42" Vizio No Picture has Backlight

    Pictures of the main board? Also have you checked the Voltage regulators on the main board?

    Comment

    • MisterD
      Badcaps Veteran
      • Oct 2012
      • 668
      • United States

      #3
      Re: 42" Vizio No Picture has Backlight

      Originally posted by XmouseX
      Pictures of the main board? Also have you checked the Voltage regulators on the main board?
      Being a newer set this main board does not have the typical AMC1117 Voltage regulators, here's some pictures I found on the net of the same exact boards this set uses. I have only checked the voltages on the fuses.
      Attached Files

      Comment

      • MisterD
        Badcaps Veteran
        • Oct 2012
        • 668
        • United States

        #4
        Re: 42" Vizio No Picture has Backlight

        Originally posted by MisterD
        Being a newer set this main board does not have the typical AMC1117 Voltage regulators, here's some pictures I found on the net of the same exact boards this set uses. I have only checked the voltages on the fuses.
        More Main Board Pictures
        Attached Files

        Comment

        • XmouseX
          Senior Member
          • Aug 2011
          • 158
          • US

          #5
          Re: 42" Vizio No Picture has Backlight

          Sorry to ask, but can I get a close up picture of the area where the back light cable plugs in. Like a 2 inches perimeter around the connector. Also are all your surface mounted fuses good?

          Comment

          • MisterD
            Badcaps Veteran
            • Oct 2012
            • 668
            • United States

            #6
            Re: 42" Vizio No Picture has Backlight

            Originally posted by XmouseX
            Sorry to ask, but can I get a close up picture of the area where the back light cable plugs in. Like a 2 inches perimeter around the connector. Also are all your surface mounted fuses good?
            The backlights are working and they are LED, they are powered directly from the power supply board therefore there's no need for inverter boards. Do you still want a close up picture of where the back light cables plugs in?
            Thanks!

            Comment

            • MisterD
              Badcaps Veteran
              • Oct 2012
              • 668
              • United States

              #7
              Re: 42" Vizio No Picture has Backlight

              Okay, I seem to be at a Stand Still with this one, being a newer LED TV, I'm not getting much help. I went ahead and ordered a replacement T-Con Board in hopes that it will fix my problem. Thanks.

              Comment

              • MisterD
                Badcaps Veteran
                • Oct 2012
                • 668
                • United States

                #8
                Re: 42" Vizio No Picture has Backlight

                Question: If the backlights are working and the LCD Panel is not doing anything, does it still let the backlight shine through to form a white or grayish screen? in other words does the LCD Sceen have to be working in order to see anything such as a white display with no picture? or is that just the backlight you see on the screen?

                Comment

                • budm
                  Badcaps Legend
                  • Feb 2010
                  • 40746
                  • USA

                  #9
                  Re: 42" Vizio No Picture has Backlight

                  You can easily verify that by disconnecting the cable to the LVDS cable from the T-CON.
                  http://s807.photobucket.com/albums/y...t=DSCF1912.jpg
                  But the high contrast screen, you may not easily see the glow.
                  Never stop learning
                  Basic LCD TV and Monitor troubleshooting guides.
                  http://www.badcaps.net/forum/showthr...956#post305956

                  Voltage Regulator (LDO) testing:
                  http://www.badcaps.net/forum/showthr...999#post300999

                  Inverter testing using old CFL:
                  http://www.badcaps.net/forum/showthr...er+testing+cfl

                  Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                  http://s807.photobucket.com/user/budm/library/

                  TV Factory reset codes listing:
                  http://www.badcaps.net/forum/showthread.php?t=24809

                  Comment

                  • MisterD
                    Badcaps Veteran
                    • Oct 2012
                    • 668
                    • United States

                    #10
                    Re: 42" Vizio No Picture has Backlight

                    bud, can you tell me which cable or cables to disconnect from the T-Con ? here are more pictures from my actual tv I'm working on. Thanks.
                    Attached Files

                    Comment

                    • budm
                      Badcaps Legend
                      • Feb 2010
                      • 40746
                      • USA

                      #11
                      Re: 42" Vizio No Picture has Backlight

                      Not sure if the backlights will still come on if you remove the LVDS cable and the power cables.
                      Attached Files
                      Never stop learning
                      Basic LCD TV and Monitor troubleshooting guides.
                      http://www.badcaps.net/forum/showthr...956#post305956

                      Voltage Regulator (LDO) testing:
                      http://www.badcaps.net/forum/showthr...999#post300999

                      Inverter testing using old CFL:
                      http://www.badcaps.net/forum/showthr...er+testing+cfl

                      Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                      http://s807.photobucket.com/user/budm/library/

                      TV Factory reset codes listing:
                      http://www.badcaps.net/forum/showthread.php?t=24809

                      Comment

                      • MisterD
                        Badcaps Veteran
                        • Oct 2012
                        • 668
                        • United States

                        #12
                        Re: 42" Vizio No Picture has Backlight

                        I also tried to get sound by hooking up a dvd player to the RCA Composite and audio input jacks and pushing the input button on the remote control but no results, but I did notice the brightness change while pushing the remote input button several times.

                        Comment

                        • budm
                          Badcaps Legend
                          • Feb 2010
                          • 40746
                          • USA

                          #13
                          Re: 42" Vizio No Picture has Backlight

                          If you have backlights which its job is for the light source only so you can see pictures on the screen, the it sounds like the T-CON may be bad or video processing may be bad, but since you are not getting the sound (not 100% sure) then the main board may have problem, it can be FIRMWARE is corrupted or bad EEPROM. I wish I have the answer.
                          Never stop learning
                          Basic LCD TV and Monitor troubleshooting guides.
                          http://www.badcaps.net/forum/showthr...956#post305956

                          Voltage Regulator (LDO) testing:
                          http://www.badcaps.net/forum/showthr...999#post300999

                          Inverter testing using old CFL:
                          http://www.badcaps.net/forum/showthr...er+testing+cfl

                          Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                          http://s807.photobucket.com/user/budm/library/

                          TV Factory reset codes listing:
                          http://www.badcaps.net/forum/showthread.php?t=24809

                          Comment

                          • MisterD
                            Badcaps Veteran
                            • Oct 2012
                            • 668
                            • United States

                            #14
                            Re: 42" Vizio No Picture has Backlight

                            If you look at the bottom of the mainboard just above the RGB Connector there are small black plastic squares the one on the left is labeled "audio" it's a small audio jack the one on the right has a gray cover over it and it is labeled "optical" when I push the input selector on the remote there is a red light behind the gray cover on the optical jack, if I leave the input so the red light stays on the tv will shut itself off in 1 minute or less, I'm not sure why and was also wondering what the small audio jack is for? Thanks

                            Comment

                            • MisterD
                              Badcaps Veteran
                              • Oct 2012
                              • 668
                              • United States

                              #15
                              Re: 42" Vizio No Picture has Backlight

                              Originally posted by budm
                              If you have backlights which its job is for the light source only so you can see pictures on the screen, the it sounds like the T-CON may be bad or video processing may be bad, but since you are not getting the sound (not 100% sure) then the main board may have problem, it can be FIRMWARE is corrupted or bad EEPROM. I wish I have the answer.
                              The T-CON board I ordered is on the way, I should get it soon, I hope that will fix it, I will keep you posted. Thanks.

                              Comment

                              • budm
                                Badcaps Legend
                                • Feb 2010
                                • 40746
                                • USA

                                #16
                                Re: 42" Vizio No Picture has Backlight

                                That is what is called TOSLINK using Optical (light source such as red LED you are seeing) for digital audio. The small 3.5mm AUDIO may be for the PC Audio input which is close to tghe PC VGA connector.
                                http://en.wikipedia.org/wiki/TOSLINK
                                Last edited by budm; 11-09-2012, 03:13 PM.
                                Never stop learning
                                Basic LCD TV and Monitor troubleshooting guides.
                                http://www.badcaps.net/forum/showthr...956#post305956

                                Voltage Regulator (LDO) testing:
                                http://www.badcaps.net/forum/showthr...999#post300999

                                Inverter testing using old CFL:
                                http://www.badcaps.net/forum/showthr...er+testing+cfl

                                Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                                http://s807.photobucket.com/user/budm/library/

                                TV Factory reset codes listing:
                                http://www.badcaps.net/forum/showthread.php?t=24809

                                Comment

                                • MisterD
                                  Badcaps Veteran
                                  • Oct 2012
                                  • 668
                                  • United States

                                  #17
                                  Re: 42" Vizio No Picture has Backlight

                                  Originally posted by budm
                                  That is what is called TOSLINK using Optical (light source such as red LED you are seeing) for digital audio. The small 3.5mm AUDIO may be for the PC Audio input which is close to tghe PC VGA connector.
                                  http://en.wikipedia.org/wiki/TOSLINK
                                  Okay, Thanks!

                                  Comment

                                  • MisterD
                                    Badcaps Veteran
                                    • Oct 2012
                                    • 668
                                    • United States

                                    #18
                                    Re: 42" Vizio No Picture has Backlight

                                    Originally posted by budm
                                    If you have backlights which its job is for the light source only so you can see pictures on the screen, the it sounds like the T-CON may be bad or video processing may be bad, but since you are not getting the sound (not 100% sure) then the main board may have problem, it can be FIRMWARE is corrupted or bad EEPROM. I wish I have the answer.
                                    Hi Budm, After trying different input sources again I did get sound, I'm using a dvd player with composite video/rca jacks/audio in, since there is no video and you can't see what input you select I figured out each time you push the input button on the remote it takes at least 7 seconds to take affect so I actually would do this, push input on the remote wait 10 seconds, push input again and wait 10 seconds, I kept doing this and eventually got the right one and Bingo we have sound. Now I'll be real glad to get my new/used T-Con Board. Thanks again.

                                    Comment

                                    • budm
                                      Badcaps Legend
                                      • Feb 2010
                                      • 40746
                                      • USA

                                      #19
                                      Re: 42" Vizio No Picture has Backlight

                                      How expensive is the T-CON?
                                      Never stop learning
                                      Basic LCD TV and Monitor troubleshooting guides.
                                      http://www.badcaps.net/forum/showthr...956#post305956

                                      Voltage Regulator (LDO) testing:
                                      http://www.badcaps.net/forum/showthr...999#post300999

                                      Inverter testing using old CFL:
                                      http://www.badcaps.net/forum/showthr...er+testing+cfl

                                      Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                                      http://s807.photobucket.com/user/budm/library/

                                      TV Factory reset codes listing:
                                      http://www.badcaps.net/forum/showthread.php?t=24809

                                      Comment

                                      • MisterD
                                        Badcaps Veteran
                                        • Oct 2012
                                        • 668
                                        • United States

                                        #20
                                        Re: 42" Vizio No Picture has Backlight

                                        $54.99 Free Shipping from E-Bay.

                                        Comment

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