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Technical Problem (advice needed)

Discussion in 'Televisions' started by mrdave21, Feb 17, 2003.

  1. mrdave21

    mrdave21
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    Hi all,

    i am hoping that someone will have the expertise to guide me in the right direction as to what is going on. I have a Teac 51 cm TV (basic CRT), which has begun to output very poor picture quality. Basically, the problem is that dark colours come out WAY TOO DARK, to the point that some scenes (ie night scenes) are unwatchable. the problem also manifests in that faces are unrecogniseable (in most cases). To illustrate the problem, the blue-background the set has to unprogrammed channels (ie. where 'snow' would otherwise be), has at its worst, appeared black.

    The picture is generally fine for lighter colours, except occasionally they appear too bright- eg. people's faces will apear a bright orange instead of skin colour, or grass is very bright green. This makes for very strange viewing especially when combined with the accentuated dark's described above!!

    The only way i can watch the TV atm, is to put the brightness up very high, like 90/100. However, i do not really see this as a permanent solution, since it really shouldn't be that high.

    I am by no means an expert on AV stuff. i bought a surround sound system (kenwood) a few weeks ago, and admittedly, have had 2 100 watt bookshelf side speakers, and a 100 centre speaker quite close to the TV set (ignorance!). The archives suggest that this might cause "deguassing" (?) or "doming", however, the symptoms commonly referred to, dont seem to appear in my case. Usually people complain of coloured patches on the screen, or fixed discolouration. I have neither of these problems, simply that dark colours are way too dark (almost like there is no contrast amongst dark colours). Also, i have tried the suggested remedies, by turning the set off, and removing the speakers- however, the problem remains.

    Given the above, can anyone think of what might be the problem. I apologize if it is something simple and obvious, but i really just dont know. Thanks,

    Dave.
     
  2. mrdave21

    mrdave21
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    the specs, if they add any meaning are

    TV: Teac CT 5150H

    DVD: Kenwood DVF 3060
    Amp: KRF-V4060D

    Speakers, 100W Kenwood Speakers, LS-V120W

    I also have a PS2 hooked up to the above.
     
  3. Chris Muriel

    Chris Muriel
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    Sounds like a fault in the TV tube's drive circuitry ; you need an engineer familiar with that TV to tell you much more as not all CRTs are driven in the same way.

    Chris Muriel
     
  4. mrdave21

    mrdave21
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    Thanks, i guess i was also wondering whether i could have in any way caused this problem with the speakers being positioned too close to the TV (the middle speaker is on a shelf just below it, and left-right to either side, half a foot away). Could this be like the first signs of a degaussing problem?? Or does it sound like something more related to the tube circuitry, unrelated to the speaker positioning?? If so, what other signs might there be that the tube circuitry is stuffed (ie. if there are any- the colour problems may be conclusive/obvious in itself????)

    i read somewhere that the middle speaker should never be positioned below the set. Is this true??

    Thanks, and sorry for all the newbie type questions. If there is a faq or something that might be useful to me, could someone point me in that direction as well.

    Dave.

    BTW- what exactly is "doming"?? My searches have only revealed scant information.
     
  5. fraggle

    fraggle
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    If it was magnetic staining this would affect the colours, not the brightness/contrast levels.

    Check the contrast hasn't been wound all the way up and the brightness dropped a lot.

    If everythings as it should be and you can't get a good picture by adjusting brightness/contrast it does sound like a tube drive circuit fault.

    Depending on the age of the TV this could be just the excuse you're looking for to buy a nice shiney new w/s set :)
     

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