28P37 - Edge of screen distortion

Discussion in 'General TV Discussions Forum' started by Orwella, Oct 27, 2004.

  1. Orwella

    Orwella
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    Just got the above Tv and I am very pleased with it apart from one thing. I can see what I believe to be magnetic distortion lines occuring at the far left and right edges of the screen. I imagine this is caused by poor shielding of the side speakers and wonder if there is anything I can do to reduce this, or if it is worth my while getting a replacement from Allders.

    I have heard that I may be able to improve thins via the service menu but do not really want to play with this blindly.
     
  2. LV426

    LV426
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    Assuming this is a direct-view CRT (right?) then magnetic interference is much more likely to result in colour impurity (seen as staining) than bent lines (which is, I guess, what you are describing; if not, ignore me).

    Bent lines are not normally due to external magnetism. More probably:

    a) if constant in (mis)shape this is a geometry adjustment which you may be able to improve in the service menu

    b) if they vary in amount of "bend" depending on how bright the image is then this is caused by poor voltage regulation, caused in turn by a barely adequate (or inadequate) power supply. Whilst you may be able to partly offset some of it with a geometry adjustment, the only other thing you can do to limit the actual change, between bright and dark, is to reduce brightness and/or contrast to lower levels. Poor voltage regulation isn't fixable.

    Unfortunately, this is one area in which CRTs do not excel. The only sure route to perfect geometry and stability is LCD/Plasma direct view.
     
  3. Orwella

    Orwella
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    Thanks for that. Bent lines is exactly what I am seeing, and only under certain brightness/contrast conditions.

    As the TV (28" widescreen CRT) is brand new is it worth me getting a replacement from Allders?
     
  4. DRGL

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    A replacement would be the same. Different TV with better power regulation would be the answer ;)
     
  5. LV426

    LV426
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    A replacement won't necessarily be any better. This varied bending (depending on brightness) is a design factor; the PSU installed is built down to a price, rather than up to a standard, and they'll all be the same, more or less. It isn't considered a fault, and it's unlikely to be the case that your 28P37 is worse than the next. Virtually all brands exhibit the same thing, too. You have to go way upmarket to minimise the effect reliably - brands such as Loewe tend to be better specified in this type of area, but you pay for it.
     

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