Weird curved lines on TV?

Discussion in 'Archived Threads 2001-2004' started by Martin Fontaine, Jul 8, 2002.

  1. Martin Fontaine

    Martin Fontaine Supporting Actor

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    This would seem to be like a magnetic problem, as if some lines were going from the sides of the TV toward the center away from the top and bottom.

    A drawing is needed to understand:
    Code:
    +---------------+
     | /// \ |
     |---/// \---|
     |---// \---|
     |---\ //---|
     |---\ ///---|
     | \ /// |
     +---------------+

    Of course there are more lines and they are more curved than the drawing above. Sort of like, back in elementary school, when they showed us basic physics with magnets and lead powder drawing lines on the sheet showing the magnetic field. It looks more or less like this pattern.

    The thing is, I only noticed these for about a week or 2, and the only things that changed is that I tweaked the service menu's V/H Size and V/H Position to reduce overscan and brought my SNES out of the closet to play some good old games (In CS5.1!!) I notice it more when playing SNES (The line pattern stay put) than when watching DVDs (In which case, the line pattern seems to flicker a bit) And is mainly noticable when the color is almost constant for most of the frame (When navigating through a cave in FF3 or when someone's head is in the middle with a constant background such as a wall behind).

    What causes this? And is there chances of permanent damage to my TV?

    The TV is question is a 4 year old Panasonic 27", the DVD player is routed to a Kenwood VR-509 for S-Video switching, the SNES is using Composite Cable (Again routed through receiver) But the receiver routing hasn't changed since I started noticing the problem so I doubt that is the cause. I have a pair of Paradigm Titans on each sides (about 2 feet from the TV) and a Paradigm CC-170 on top (But that one is shielded) but the speakers have been there since mid april so I would have noticed it by now if they were the cause.
     
  2. RyanDinan

    RyanDinan Stunt Coordinator

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    It sounds like the TV (the CRT) has become magnetized, and needs to be degaussed.
    Most modern computer monitors have this feature built-in, as they are typically around unshielded speakers and such. Even though your speakers are shielded, they can still cause this to happen over a period of time...

    I would call Panasonic and have them send someone out - if your set is still under warranty. If not, you may want to get an estimate from a local repair shop - and see if that's really the problem....

    Good luck,

    Ryan
     
  3. Daniel V

    Daniel V Auditioning

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    Hey....

    He's right you know, the screen could have been magnified! If you have somthing with a strong magnet in it, it could bee a subwoofer or some speakers, then try vto remove them from your screen! If it doesn't help, then have someone that knows something about the problem to check on it!

    , Daniel
     
  4. Martin Fontaine

    Martin Fontaine Supporting Actor

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    Ok, but anything that could possibly have magnets (Speakers) have been there for a lot longer than I've noticed the problem.

    But don't magnetic fields on a TV produce colored spots? Not lines? When watching a 480i source (TV or DVD since my TV/DVD Player are not progressive scan) then the lines seem to be flickering to I guess it's not permanent and that whatever could be done (Degaussing?) would fix it. But when viewing a 240p image (The SNES and most old game consoles where displaying 60 fps but only on every other lines so I guess that mode would be called 240p) then the lines are stable, not colored though, just darker than the image that is there. It's mostly noticable when it's an even surface.
     
  5. Martin Fontaine

    Martin Fontaine Supporting Actor

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    I went in the service menus, and played with the Vertical Size setting, and putting it back to what it was removed the lines. So the cause really is sort of an optical illusion caused by the proximity of the scan lines with the curvature of the screen. Nothing to worry about, and since it rarely shows, I'd rather have that than 6% overscan!
     

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