"Michael Kennedy" wrote in message
...

"AZ Nomad" wrote in message
...
On Sat, 4 Sep 2010 00:18:51 +0900, Michael Kennedy
wrote:

"Meat Plow" wrote in message
news On Fri, 03 Sep 2010 23:45:09 +0900, Michael Kennedy wrote:

I don't have this tv in hand now and also don't have the make and
model
of this display at the moment but all I am looking for is general
information for now.

This tv has a smudged / blurry area on the screen. It looks almost
like
it is dirty from a oily hand but it doesn't wipe off. It is not a
rectangular area.

I am not familar with the common failure modes of Plasma displays.
What
is your best guess would cause this.

Thanks in advance,

Mike

Since it only covers a non-symmetrical portion of the screen my
guestimate would be the screen itself.


Thanks for the insight Meat.

These aren't affected by magnets the way CRT sets are they? Sorry for the
stupid questions, but I have never taken apart, owned or even used a
plasma
display. I am only familiar with the VERY basic principles of operation
and
know it uses phosphors which are similar to a CRT but uses some other
method
to illuminate the phosphors. I guess uses some kind of micro printed
circuitry similar to an LCD display, but I could be totally wrong about
that.

There is no convergance nor is there any concept of focussing. The
pixels are fixed in size and location and nothing can affect that.

That's the question I was wondering.. Thanks!
I've got a little better idea of how this thing works now. Before it was
all speculation.


It was not unknown for plasma cells on older panels to develop a 'memory' of
some bright content that had been displayed, resulting in a sort of visible
'stain'. In the worst case, this could cause permanent damage to the cells
in the area, but often, the effect could be negated with a special service
mode that did an intense white wipe of the panel. I'm pretty sure that
modern panels don't suffer from this problem, and are much less susceptible
to cell burn from high intensity static displays, but if the set is more
than a few years old, it might be worth checking to see if there is a
service mode that carries out a panel wipe. It may even be available as a
user function through one of the menus.

Have a read of

http://en.wikipedia.org/wiki/Plasma_display

For a good description of the principles involved

Arfa