Magnetic shielding problem with RPTV?

Discussion in 'Archived Threads 2001-2004' started by Brian Cal, Jan 7, 2002.

  1. Brian Cal

    Brian Cal Stunt Coordinator

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    I've had my Toshiba 57H81 for about 5 months now. On top of the set is the JBL S-center, and about 10 inches on either side of the set are the JBL S-38 mains. All of these speakers are magnetically shielded. About 3 feet to the right of the TV is a JBL PB12 subwoofer, which I'm not sure is magnetically shielded or not.

    The problem is that two nights ago I noticed a very small discolorization on the right side of the screen, a problem I always thought resulted when there is magnetic interference. The spot is very small, only about half the size of a penny, but I'm afraid if I let it go it will grow much bigger over time. On my old 27" direct view I had some speakers that weren't magnetically shieled sitting too close to the tv and it resulted in a permanent color "splotch" about the size of a golf ball. I DO NOT want this happening with my RPTV.

    I'm a little confused as to why the spot is there, since I thought magnetic intereference wasn't as much of a problem with RPTVs as it was with direct views, and also since I thought setting my subwoofer 3 feet from the tv would be plenty of distance to avoid any potential interference.

    Could my sub really be interfering with the TV's CRTs, or could the problem lie elsewhere? Any advice would be greatly appreciated, I'm freaking out.
     
  2. Glenn Overholt

    Glenn Overholt Producer

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    I know it isn't with the speakers. I was so strongly corrected on this several months ago.

    With a direct view, the magnet on the neck of the TV tube aligns the phosphors in the tube to produce the picture, and having an unshielded speaker nearby introduces problems...

    However, with an RPTV, there is no tube, and no neck, and thus no magnet or phosphors, so no interference.

    I don't know. Maybe a bug landed on one of the lenses?

    Glenn
     
  3. Kevin P

    Kevin P Screenwriter

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    A small area of discoloration doesn't sound like a magnetic shielding problem to me. On a RPTV, with three separate CRTs, unshielded speakers would cause problems with convergence more than anything else.

    What color is the splotch? It's probably dirt on or inside a lens, or on a CRT surface (or less likely, a defect in the CRT). If you display a white screen (on the AVIA DVD, or during a show, commercial or DVD menu with a white background), if the splotch is yellow, the problem is with the blue CRT or lens. If it's magenta (purple), the problem is with the green CRT or lens. If it's cyan (light blue) it's the red CRT or lens.

    KJP
     
  4. JimHal

    JimHal Stunt Coordinator

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    I had a similiar problem. However, after looking close I had three spots, yellow, green and purplish.

    I had a fingerprint on the mirror.

    Maybe it is just a little dirt on the mirror. Or like others have said, it could be a little dirt on a particular gun.

    Good luck.
     
  5. Brian Cal

    Brian Cal Stunt Coordinator

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    Thanks for all the replies. The discoloration is most prominent on a white or yellow background, and from memory I know it's blue over a yellow background, but I'm not sure what color it is over white (blue also, I think).

    So it sounds like the mirror or lenses might be dirty? How does something like that happen? Everything was fine up until two nights ago.

     

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