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42LG30 Vetical bars

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    #1

    42LG30 Vetical bars

    A friend found this in the trash. Powering it on the screen starts up solid black then the bars "wash" in as seen in the picture. There are 2 ribbons that go to the panel from the tcon board. If we disconnect the one side the bars appear as soon as the backlight comes on and it's across the entire screen. If the other side is disconnected the bars are there but the other half is white.

    I would think by having one ribbon connected and the other disconnected one half would be white but it's not the case with the one side. We did check the voltages coming from the power supply and they all check out as per the legend on the board. If we hit the menu button nothing shows up on the screen.

    We did try and hook a source up on the screen and started hitting the source button and did get audio. The bars do start to strobe. The tcon board is very cheap ($13) with free shipping.

    So the million dollar question is: Does this appear to be a faulty tcon, main or panel. I don't think it's the main board since the tv turns on/off and the source can be changed but from my experience in this area i'm usually wrong . Just want to get some feedback before investing a dime on this tv.

    Thanks
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    #2
    Re: 42LG30 Vetical bars

    Looks like t-con or panel to me, my bet would be on t-con, worth a $13 gamble for a free TV. Fading lines are characteristic of LCD driver problems -- the main board can't usually cause that.
    Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
    For service manual, schematic, boardview (board view), datasheet, cad - use our search.

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      #3
      Re: 42LG30 Vetical bars

      I placed the order. I'll update this thread when i get the board. Hopefully it's not the panel but for the price it's worth the gamble.

      Thanks

      Comment

        #4
        Re: 42LG30 Vetical bars

        Originally posted by Mr Bill View Post
        The tcon board is very cheap ($13) with free shipping.
        With the recent USPS $7 hike across all International shipping options, I can't even get an empty box filled with air shipped to Canada for $13.
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          #5
          Re: 42LG30 Vetical bars

          Tom, since I'm dealing with a fading to black Toshiba TV and you are saying that can also be a panel driver IC problem, that is possible that all of them are failing at once?

          Comment

            #6
            Re: 42LG30 Vetical bars

            How likely is it that all ICs would fail simultaneously?
            Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
            For service manual, schematic, boardview (board view), datasheet, cad - use our search.

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              #7
              Re: 42LG30 Vetical bars

              Yes.

              Comment

                #8
                Re: 42LG30 Vetical bars

                I don't understand what you mean.
                Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                Comment

                  #9
                  Re: 42LG30 Vetical bars

                  It's possible that all tab drivers to go bad at the same time?
                  Only like that can the whole screen go black, no?

                  Comment

                    #10
                    Re: 42LG30 Vetical bars

                    Unless the t-con kills them, which is very rare. The 15V would have to go out of control. HOWEVER, one failed IC can cause the others to malfunction.
                    Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                    For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                    Comment

                      #11
                      Re: 42LG30 Vetical bars

                      I got the replacement tcon today and the display is exactly like before. We will just pull the power supply and inverter and ebay them. Then recycle the rest.

                      Comment

                        #12
                        Re: 42LG30 Vetical bars

                        Before i strip the tv down and recylce it i thought i would show a video of what it's doing. My friend is stubborn and wants to exhaust all options before the tv is completley killed.

                        I said in post #1 that there was audio. I was WRONG. i've tried several times today with different devices and i cannot get any audio. He wants to know if the main board could be a "likely" cause for this fault. I think pesonally it's the panel but without audio i could be wrong. SO i told him i would update this thread one last time and get hopefully a few opinions.

                        http://www.youtube.com/watch?v=N_0Hi...ature=youtu.be

                        Comment

                          #13
                          Re: 42LG30 Vetical bars

                          although you can't see any video to tell where you are on the screen using the remote control or side buttons cycle through the inputs slowly, try turning up the audio. what do you have as your source? dvd player? Cable TV Box?

                          Do you see any signs of anything other than the vertical bars when pushing the Menu button? one other suggestion is to heat the top of the panel area with a hair dryer and also try slightly twisting the panel with the back off, sometimes one or both of these methods can temporarily return to a normal screen if the panel is bad or has bad tab bonds.
                          Last edited by MisterD; 02-25-2013, 12:05 AM.

                          Comment

                            #14
                            Re: 42LG30 Vetical bars

                            Fading lines are panel or t-con only; the main board deals with discrete values and it's pretty uncommon for it to produce an output that fades in such a way. One thing I did notice is that TV sure takes a long time to boot. I don't know for sure if it's normal but it seems odd. Does this TV have an RS232 port on the rear?
                            Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                            For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                            Comment

                              #15
                              Re: 42LG30 Vetical bars

                              I thought the same thing about the tv turning on slowly. It does have a RS232 port on the back of the set.

                              Comment

                                #16
                                Re: 42LG30 Vetical bars

                                Using the RS232 port you can hook it up to a computer, and send it commands. There's usually a full list in the LG operations manual. Commands may be used to adjust the volume, switch sources etc to check main board operation.
                                Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                                For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                                Comment

                                  #17
                                  Re: 42LG30 Vetical bars

                                  i'll have to look and see if one of my older computers in the basement has a COM port on it. My current computer doesn't have a COM port on it. Does this take some special software to run?

                                  Comment

                                    #18
                                    Re: 42LG30 Vetical bars

                                    Just ordinary RS232, the baud rate, parity and other settings are printed in the manual, you use HyperTerminal to send the commands.

                                    You can use a device such as this: http://www.ebay.com/itm/USB-2-0-to-R...item2c58ade216
                                    Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                                    For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                                    Comment

                                      #19
                                      Re: 42LG30 Vetical bars

                                      Originally posted by MisterD View Post
                                      although you can't see any video to tell where you are on the screen using the remote control or side buttons cycle through the inputs slowly, try turning up the audio. what do you have as your source? dvd player? Cable TV Box?

                                      Do you see any signs of anything other than the vertical bars when pushing the Menu button? one other suggestion is to heat the top of the panel area with a hair dryer and also try slightly twisting the panel with the back off, sometimes one or both of these methods can temporarily return to a normal screen if the panel is bad or has bad tab bonds.
                                      ? Have you tried this?

                                      Comment

                                        #20
                                        Re: 42LG30 Vetical bars

                                        Twisting = nothing
                                        Heating tabs = nothing
                                        Hitting the menu, volume, channel keys = nothing
                                        I've tried a dvd player with component, av, & HDMI and i cannot get sound even though i've set the player up on a working set then swapped the cables over to this tv. I even ran straight cable to the tv. I don't have a remote though i thought about (not done yet) setting up a universal remote to see if i can change the source.

                                        I ordered the RS232 cable Tom recommended to try the Hyper Terminal commands to see if the set will change sources. If the main board wasn't so expensive i'd almost try it but i don't want to risk the $$$.

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