Plasma TV Foggy area
Michael Kennedy
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
Meat Plow
Since it only covers a non-symmetrical portion of the screen my
guestimate would be the screen itself.
--
Live Fast, Die Young and Leave a Pretty Corpse
Randy Day
mi...@nospam.com says...
Someone used solvent to clean the screen?
--- news://freenews.netfront.net/ - complaints: ne...@netfront.net ---
Michael Kennedy
"Meat Plow" <mhy...@yahoo.com> wrote in message
news:pan.2010.09...@hahahahahahahah.nutz.I.am...
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.
Michael Kennedy
"Randy Day" <rand...@sasktel.netx> wrote in message
news:MPG.26eaccdb1...@202.177.16.121...
> In article <VridnT16DI5klBzR...@giganews.com>,
> mi...@nospam.com says...
>> 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.
>
> Someone used solvent to clean the screen?
>
Interesting idea.. That's a case where the screen could be fixed... I will
have a close look at it in a couple of days.
The price is right on this thing, but I don't want to sink money into it if
the screen is about to crap out.. Since that's the one piece that cant be
repaired.
Meat Plow
The phosphors are illuminated by bursts of plasma emitting a UV light not
an electron beam. Cells are filled with gases including a small amount of
mercury. Each cell is capable of the three primary colors and depending
on the amount of electricity applied to the cell controls the intensity.
That's about it for my understanding.
AZ Nomad
There is no convergance nor is there any concept of focussing. The
pixels are fixed in size and location and nothing can affect that.
Michael Kennedy
Hmm.. Interesting. Plasma bursts.Hence why it's called a Plasma display..
Thanks for the basic run down.
Michael Kennedy
"AZ Nomad" <azno...@PremoveOBthisOX.COM> wrote in message
news:slrni825ad.g...@ip70-176-155-130.ph.ph.cox.net...
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.
Michael Kennedy
complicated arangement...
Meat Plow
What fascinates me still is the workings of a DLP.
Michael Kennedy
Agreed.. Quite amazing what can be done with a silicon chip.
William Sommerwerck
A good suggestion.
It's hard to imagine a plasma screen being "out of focus", as there is
nothing /to/ focus -- that I'm aware of.
Ken
Aren't the front of the screens made of glass??? If so, how would a
solvent affect the screen?
Michael Kennedy
"Ken" <K...@invalid.com> wrote in message
news:i5r82t$qsj$1...@news.eternal-september.org...
Yes but its coated with an anti-glare surface. Just like any quality CRT
monitor had. That as well could be destroyed if you used a solvent based
cleaner on it.
Plain...@yawho.com
wrote:
As has already been suggested, it must be someting on the surface of
the panel itself. Use of a cleaner is one possibility. Another is
some sort of grease or other material.
Some replacement panels have a protective film. If that was not
removed at the factory, or it left a residue, that would be a possible
result. IMHO, that's an extreme long shot.
One good source of information on Plasma displays is to Google 'Plasma
training manual Scribd' This will bring up a number of training
manuals. The LG ones in particular have much information on the
actual construction of the panel. The down side is it is the
translation was horrible.
PlainBill
Jamie
soot to cover the inside of the screen a bit?
Jamie
Arfa Daily
"Michael Kennedy" <mi...@nospam.com> wrote in message
news:7vqdnYbfH6htixzR...@giganews.com...
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
Mark Zacharias
Lets not get ahead of ourselves - do we know for sure it's really a plasma
and not an LCD? My customers often confuse the two.
If not damage to anti-glare coating which has been suggested, it does sound
more like an LCD type problem to me.
Mark Z.
Meat Plow
If the screen protector was damaged by some solvent it would be easy to
tell using a little oblique lighting
mike
Dust/Dirt gets sucked in by fans and deposits itself
on any available internal surface.
Arfa Daily
"Mark Zacharias" <mark_za...@sbcglobal.net> wrote in message
news:4c821684$0$6000$c3e...@news.astraweb.com...
To be honest Mark, I'm not sure that as described, it actually sounds like
any kind of display technology fault that I have seen. I would be struggling
to think of any kind of LCD problem that would result in an irregular
smudgy-looking mark, unless it was an actual physical mark on the surface of
the panel ...
Arfa
Michael Kennedy
"Arfa Daily" <arfa....@ntlworld.com> wrote in message
news:D6Lgo.38838$Kp4....@newsfe22.ams2...
I will let you know if I finally get a chance to see this thing again.. I
saw it very briefly and it wasn't a major flaw. Had I not been told about
it, I'm not sure that I would have noticed right off. Seeing it I thought
it was a very strange fault if electronic, but I haven't seen a plasma fail
except in getting darker or burn-in. Anyway. . Hopefully I will see it
tomorrow and solve this mystery.
Michael Kennedy
Ok I got another look at this TV. It is a Hitachi W32-P5000
Upon close inspection it appears that there is something on the inside of
the front glass.
You can tell by looking closely moving side to side and watching pixels go
from blury to clear
My next question is that is the front glass typically seperate from the
plasma display or is it part of the
display like an LCD tv. If it is indeed seperate it would be an easy fix.
My best guess is
that its seperate but as I said I dont know anything about these and dont
want to drop $160
on something that I cant fix.
By the way, thanks everyone for all of the insight. This group has always
helped me in my
electronic ventures.
Michael Kennedy
Forgive me if this is a double post. It seems that it didn't work.
I had a closer look at the TV today. It is a Hitachi W32-P5000.
Upon closer inspection it appears that the "fog" is on the inside of the
front glass. I can tell by looking closely and moving side to side. The
pixels were obviously clear and the front glass is fogged.
The next question is that if the front glass is attached to the Plasma
display.
If its not this should be an easy fix.
Meat Plow
You'd have to get ahold of someone who has either tried to separate the
front glass or who has successfully separated it. This is going to be a
real challenge because it is not something that is normally done. I don't
think I'd toss $160 at the owner either for the chance to find out on my
own.
William Sommerwerck
"in touch with tomorrow" was Toshiba's slogan). I'm not so sure this is a
case of the protective front surface pulling away from the panel.
Bob Villa
>The next question is that if the front glass is attached to the Plasma
display.
If its not this should be an easy fix
I would pass on this unless you can live with it as it is. I am
definitely no expert but it sounds like and internally caused flaw or
manufacture flaw that was not originally seen by the owner.
Michael Kennedy
"William Sommerwerck" <grizzle...@comcast.net> wrote in message
news:i62pa5$b5$1...@news.eternal-september.org...
My best guess by looking at it is something that is on the inside of the
panel, but certainly not the actual pixels. It is definitely tolerable. If
anyone saw it they would think the TV just needed to be cleaned in that
spot.
Meat Plow
The construction on the viewing side is a dielectric layer then the front
glass. Sandwiched in the dielectric are electrodes. I think the front
glass seals the gas cells so there would be no chance of removing it if
this is the case. I don't know what the dielectric is made of, possible
glass with an oxide coating. If that were the case one would assume that
seals the cells.
William Sommerwerck
> inside of the panel, but certainly not the actual pixels. It is
> definitely tolerable. If anyone saw it they would think the
> TV just needed to be cleaned in that spot.
It would drive me stark raving bonkers.
Meat Plow
My son for some untold reason scratched the glossy protective cover on my
51" Panasonic rear projector. It was done with a pencil and maybe an inch
long vertical. It took me a very long time to stop staring at that
particular spot that wasn't anywhere near the center of the screen. I
think too that it would be too much of a distraction for me to watch a
set with a big smudge anywhere on the screen.