curious circular scratches on Panasonic 47wx49

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Archived from groups: alt.tv.tech.hdtv (More info?)

I've had this panny 47" for a year now and have been quite happy with
it but just recently I've noticed about 4 "scratches" that are in a
semi circle equi-distant from each other and about 8" long. The best
way I can describe it is if you had a bulls eye target outline and the
lines are very faint but I can see them when the screen goes to
bright white. It's on all channels I try.

Anybody want to hazard a guess as to why this is happening.

 

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Archived from groups: alt.tv.tech.hdtv (More info?)

"Elflan" <elflan@geocities.com> wrote in message
news:5b2e6a47.0406061820.7c4f83a9@posting.google.com...
> I've had this panny 47" for a year now and have been quite happy with
> it but just recently I've noticed about 4 "scratches" that are in a
> semi circle equi-distant from each other and about 8" long. The best
> way I can describe it is if you had a bulls eye target outline and the
> lines are very faint but I can see them when the screen goes to
> bright white. It's on all channels I try.
>
> Anybody want to hazard a guess as to why this is happening.

This is one guess. The screen of your set likely has two effective layers.
The front is a lenticular lens with vertical ridges and the back is a
fresnel lens with a very fine circular pattern. You typically do not see
the circular pattern. I have occasionally seen screens with contaminants
like dust, oils, or insect products that reside in the fresnel grooves and
make the pattern visible. The solution is to clean the screen if this is
the issue, but beware, the lenticular screen is broken easily and both can
be damaged. The problem may be between the screens and may require taking
them apart.

Leonard

 

[Guest]

Archived from groups: alt.tv.tech.hdtv (More info?)

"Leonard Caillouet" <no@no.com> wrote in message news:<MDYwc.58359
> >
> > Anybody want to hazard a guess as to why this is happening.
>
> This is one guess. The screen of your set likely has two effective layers.
> The front is a lenticular lens with vertical ridges and the back is a
> fresnel lens with a very fine circular pattern. You typically do not see
> the circular pattern. I have occasionally seen screens with contaminants
> like dust, oils, or insect products that reside in the fresnel grooves and
> make the pattern visible. The solution is to clean the screen if this is
> the issue, but beware, the lenticular screen is broken easily and both can
> be damaged. The problem may be between the screens and may require taking
> them apart.
>
> Leonard

Thanks much for that explanation.
When you mentioned fresnel, it's curious that I thought of that word
when I was attempting to describe my problem. Don't know exactly why.
The circular pattern is in the center of the screen.

I have a service plan that I've not used yet. I wonder if I had a
tech come out, he could clean it. It doesn't really bother me that
much but would want it fixed,(cleaned) if it something that's going to
get worse.

I was told that this screen naturally did not attract dust so I wonder
how the dust gets in between these layers?