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Discussion Starter · #1 ·
I just took delivery of my Panasonic PT50-LC13 and noticed there are two very noticable black dots on the screen. One dot actually looks slightly bigger than the other. On closer inspection, the bigger dot almost looks like a piece of dust, as it doesn't seems to take up a slight bit more space than one pixel. They're most noticable on white backgrounds, but even on the blue background that's shown when it's tuned to a station with no reception, you can still see the two black dots from 8' away once you know where it is. At the store, I had inspected another Panasonic LC13, and I had noticed there were certain pixels that had a permanent green color. But those were very faint, and cannot be seen by me from more than a few inches out. So I had just assumed that dead pixels would be faint like those, which don't bother me at all. So now my question is, are these black dots also dead pixels? I'm currently planning on exchanging the set, but I'm wondering if I should be able to expect a set with a perfectly clean picture from 8' out? Or are things like this just a part of owning an LCD RPTV?
 

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I also noticed a couple small black dirt/dust specks on my screen (Panny 50 LCD). They arn't noticable from a couple feet away.


It appears that they are caught between the LCD screen and cover screen. Panasonic should clean up their act! I'm suprised because I've been to one of their factories and was impressed with their quality control.


I've only noticed a couple dead/off color pixals and again they aren't noticable from a couple feet away. All-in-all, I'm very pleased with my new set and will not trade it in for a new or different model. If I had a problem like you've described, I probably would have.


Keep us posted. Thanks.
 

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From what I understand, if you have any dead or stuck pixels, they will most likely stay that way. On the plus side, as I understand it, you should not later get more of these. They are either working or not working from manufacturing. At least, this is how I understand the technology to work.


Also, for those that don't realize it, there is a difference between a dead and a stuck pixel.


You have three panels (Red, Green, Blue) that are all overlaying each other. A pixel (on any of these panels) can either be stuck or dead (on or off). If a particular pixel in all thee panels was dead, it would always be black. If it was stuck on all three, it would always be white. If one panel had a stuck pixel, and a black screen was supposed to be shown, then that pixel would show up in that color of the panel it was stuck on (R, G, or B). If it were dead, it would affect that pixel's ability to render an accurate color, as one of the three primary colors for that pixel would be absent. You get the idea. I know most know this already, but for those that didn't, now you do.


Where-as with DLP, you either have a stuck mirror or you don't (on or off). If it's stick, it'll always either reflect or not reflect light, through all colors of the colorwheel.


So far, as best as I have been able to tell, I do not have any stuck pixels on my Hitachi, which to me is pretty amazing, because usually LCD panels will have at least a few stuck here and there.


Most manufacturers will consider this to be normal, and honestly, so would I. This would not make much difference unless it was stuck on, and it was very bright, and it was in or near the middle of the viewing screen, or where a black bar might normally be.


Just my .02
 

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I have one of those dirt/dust specks, it crosses over 2-3 pixels and if I put pressure with my hand on top of the set I can see the pixels and screen move slightly but the speck stays where it is.

I'm guessing the speck may be on the bulb.
 

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My 50CL13 also had two black specks that were not on the back surface of the screen but on the surface behind that screen. I could tell since when I pressed in the outer screen surface, the speck didn't move (like Arkid stated above).


I returned the unit to Circuit City and got a new one. Was surprised how good they were about this. Very easy.


Now the new one doesn't have any bad pixels ! and there are no black specsk! However I've noticed that the center of the screen has a whitish almost reflection-like image going from top of the screen to the bottom. I first thought it was my reflection from my white T-shirt but looking closer it was always centered in the middle of the screen from top to bottom no matter where I moved (left or right).


Could it be that the first screen is too close to the outer screen?


The picture isn't affected or the brightness level, just when you have the TV turned off, it has this whitish reflection-like image. Very weird!


Anybody else seeing this problem with their screen?


Willy
 

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Discussion Starter · #6 ·
wh88: I'm not sure if I have the same problem as you, but at certain angles, it does seem like there's a slight white-ish looking film on the center of my screen. It looks almost as if it's a huge oil smudge or something. But it doesn't affect TV viewing at all. Only semi-noticable with the TV off and looking at it an angle.


Man, trying to get a good screen is a real stressful thing. My replacement LC13 is being delivered tomorrow... keeping fingers and toes crossed that I don't have any black specks this time!
 

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While I do not have any black spec's on my screen but I do have a extreme amount of stuck blue/green pixel's on my screen about 20% of the screen is clean in the upper left corner the rest is freckled with them. Of course can't see them until up close but that is not the point. This set is in such demand here I have not ETA on a replacement. I just think somebody need's to invent some magical pixel dust to help all us out.
 

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Discussion Starter · #9 ·
chris: If you cannot see the two red pixels from where you're watching your TV, then count your blessings and keep it! It's just about impossible to get a perfect LCD screen... I'd be real happy if I could get a screen that looks perfect from 7' away.
 

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hehe I feel a little bit better knowing there all like that but I could see the pixel from 8 feet away only when the background is dark and I have to be looking for it.... I dont know any standards for LCD but is that bad then?
 

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well if you can see it then I would think it's more than 1 pixel maybe 4 grouped. I have 1 bad spot on my t.v. that is a group of 4-6 pixels that I can see from about 6' away but only if I am looking for it. But if it bothers you go ahead and get another set. I would get another if I could see it from my viewing position. If I had only a few stuck pixels on my set I would keep it but 80% of my screen is littered with them. Can't see 90% of them unless my nose is on the screen but hopefully my new one whenever it arrives will be better if not will keep getting new one's til I'm satisfied.
 

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Globetro,


I think we both have the same problem. I shined a flashlight at the front of the screen and moved it from left to right and as the beam passed through the center of the screen it reflected more light and showed a more reflective surface -> whitish. It was only viewable at an angle but much less noticeable head-on to the screen. This test actually indicated that the center spot had more reflection and the top and bottom sections were less reflective; the reflective spot was about the size of a small coconut.


It's almost like there's a ghost in the machine ...


I can live with this imperfection as it is not visible when the TV is on. No color fading or brightness issues from this screen.


Does anyone know of any access ports on the back of the TV to clean the screen or replace the lighting element?
 

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It could also be the effect of the lenticular screen, which is rather like a fresnel lens. You could be seeing the reflections from the tiny angles in the surface.
 

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CupertinoSlim,


I understand what you're saying, but my first 50CL13 did not have this ghosting problem.


Has anyone opened up the 50LC13 from the back yet?


The unit does not look to be easily serviceable.


Willy
 

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There have been many reports of this ghosty white spot from various of the slim RP sets. The general consensus is that it is from external light being collected by the set and being reflected back on to the screen from the mirror assembly.


ron
 

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Discussion Starter · #16 ·
Got my new LC13 delivered today to replace one that had two black dust specks in it. Well, this one has one very tiny black dot in the dead center. But I can barely notice it from where I sit, so I decided it's better to keep this one than to risk getting a worst one.


I hooked up my Samsung 931 DVD player up to it and the picture is phenomenal! Absolutely amazing... I'm blown away. I've only watched a bit of Star Wars Episode 2 and a bit of LOTR:TT, but so far it looks amazing. I don't know how much of this is due to the DVI connectoin and how much of it is just due to progressive scan (as my previous Sony DVD player didn't have progressive scan), but the combination of this Samsung with the Panasonic LCD RPTV is nothing short of amazing! OK, time to tear myself away from this TV and head back to work!
 

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I got my panny on Sept 5, and haven't seen any specks ie dead or stuck pixels. (knock on wood) I did notice the whitish haze in the center of the screen, especially toward the bottom. I hadn't thought about it much and went back and looked after reading this thread. It doesn't seem nearly as pronounced now and is really not noticable unless you're expressly looking for it. I'm about to decide that it is truly one of those "break - in " issues if that's even possible. Anyone else notice the haze sort of go away over time? -Headers
 

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Quote:
Originally posted by wh88



I returned the unit to Circuit City and got a new one. Was surprised how good they were about this. Very easy.

Why you buy from a good dealer....


Restocking fees and NO Return policy, or internet shipping fees are not fun on an RPTV.


It's bad enough when somthing goes wrong.... but much worse when you have to pay more because something went wrong- or your hands are tied
 

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I've opened mine up partially buy removing the screws around the frame - you can search one of the other forums for my post. Bottom line is that it appears the main mirror and the lens are easily cleanable as well as the inner most surface to the screen. The service manual shows that the screen is a sandwich which they recommend replacing as a unit but the sandwich does come apart.
 
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