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    Westinghouse LVM-42w2 Pixel stripes

    Hello all,

    Glad I stumbled upon this forum--looks like a lot of helpful folks here. I've got a Westinghouse LVM-42w2 TV (actually it's technically just a monitor as it lacks any kind of TV tuner) that in the last month has developed horizontal "stripes" (for lack of a better word) of pixels. I tried all the usual stuff of unplugging from power for a few hours, making sure it had adequate cooling, and resetting all settings to defaults with no change.

    So I went to work testing all the inputs and resolutions. The first thing I determined is that they are not "stuck" pixels on the panel. I was able to make the stripes go away by switching to 640x480 resolution, on any input. The pixels also also change color and "dance" around on the screen. On some of the lower resolutions like 1024x768 and 1280x720 the stripes are present, larger, and towards the lower half of the screen. On 1920x1080 (the panel's native resolution) the stripes are smaller and show up towards the top of the screen. The stripes show up no matter what input I am using--HDMI, VGA, component are the ones I've tried (so both digital and analog inputs).

    Otherwise the picture is stable. I've watched various things despite the line for a few hours at a time with no other apparent problems.

    So having done a bit of research (I am no electronics expert, just a decent googler) my guess is that the problem lies in the T-Con board. From what I can tell, the T-Con basically "translates" the signals from the various inputs into the proper language the panel itself speaks. Perhaps a bad analogy, but that was my understanding of it. So given that the problem is not the panel itself (as evidenced by the fact that the stripes go away when the resolution is set to 640x480) and is not confined to any particular input, the T-Con seems to me to be a good place to start.

    But I thought I would run it by you guys to see if you think I'm on the right track or not. Looks like T-Con boards for this set are readily available on the net, but I wouldn't buy one without first taking the back off my set and looking at the particular board number.

    I've attached some photos of the effect I'm seeing. Would love to be able to get this set running again since it's only about three years old.

    Much appreciate any guidance!

    Dan
    Attached Files

    #2
    Re: Westinghouse LVM-42w2 Pixel stripes

    By your description this looks more like a scalar problem than a tcon problem. The scalar takes the input signal, scales it to fit the screen, then sends it to the LVDS cable to the tcon. The tcon translates the incoming LVDs signal into appropriate horizontal and vertical drive signals.

    PlainBill
    For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.

    Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.

    Comment


      #3
      Re: Westinghouse LVM-42w2 Pixel stripes

      Thanks very much for your reply PlainBill... this is exactly why I wanted to post here rather than just go on my uneducated assumption.

      And your reasoning makes sense. I guess if it were the tcon I would see this issue regardless of what resolution I was feeding the panel.

      OK so my follow-up question then (which you may not be able to answer since it probably varies) is where is the scalar? Looking at shopjimmy.com for my model number only pulls up two boards--the tcon and the mainboard (in addition to stuff like power supply and backlight inverter). Is the scalar usually present on the mainboard? Would you (or anyone else) be able to identify it if I took the back off the set and photographed the innards?

      Really appreciate the advice.

      Comment


        #4
        Re: Westinghouse LVM-42w2 Pixel stripes

        Originally posted by bookemdano View Post
        Thanks very much for your reply PlainBill... this is exactly why I wanted to post here rather than just go on my uneducated assumption.

        And your reasoning makes sense. I guess if it were the tcon I would see this issue regardless of what resolution I was feeding the panel.

        OK so my follow-up question then (which you may not be able to answer since it probably varies) is where is the scalar? Looking at shopjimmy.com for my model number only pulls up two boards--the tcon and the mainboard (in addition to stuff like power supply and backlight inverter). Is the scalar usually present on the mainboard? Would you (or anyone else) be able to identify it if I took the back off the set and photographed the innards?

        Really appreciate the advice.
        The scalar is part of the main board. It may be a separate chip, but I'd expect the function has been integrated into the graphics processor by now.

        I'd say it's time to see if you can purchase a main board.

        PlainBill
        For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.

        Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.

        Comment


          #5
          Re: Westinghouse LVM-42w2 Pixel stripes

          I found a matching mainboard on ebay pulled from a set which had a cracked panel (advertised as tested working). It arrived today and I just finished installing it. Problem solved!

          Thanks to you PlainBill I didn't waste time and money trying to replace the T-Con board first.

          Now hopefully this replacement will last me a couple more years at least.

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