Sony KDFE50A10 LCD TV - are stuck pixels normal?

18 Sep 2005 9:28 PM

John

I just got a new Sony KDFE50A10 LCD TV. The very first thing I noticed
(and it's my only significant gripe) is that it had 3 noticeable
"stuck pixels" for lack of a better word. In Normal (4:3) mode or when
the screen is black you don't see them, but when there is picture
information these 3 spots show up as stuck blue pixels no matter what
the background color is. One of these spots covers a few adjacent
pixels. At my normal viewing distance (10') I can't see them, but it's
one of those things that bothers me because I know they are there and
they shouldn't be.

Are stuck pixels like this normal on LCD TVs or is this a defect for
which I should exchange this set?

I haven't seen any comments about stuck pixels which is why I'm
wondering if:
(1) I got a rare defective set.
(2) everyone else knows stuck pixels are normal so nobody bothers to
mention them because they are so minor during normal viewing.
(3) I didn't use the right words when searching the net about this.

Is this stuck pixel defect in the LCD screen itself or is there any
chance it might be some tiny specks of dust inside the optics that a
repairman could blow out causing the stuck pixels to go away?

18 Sep 2005 10:21 PM

John

I need to correct a mistake I made in my previous post. I said the
stuck pixels we're only visible when bright objects were behind them
and they were always blue.

That shows how bad my memory is. It turns out the 3 stuck pixels show
up at all times, even when in Normal (4:3) mode or when there is a
black background. 1 pixel is always deep blue and the other 2 are very
light green or yellow. I don't know if that matters in diagnosing this
problem. Sorry for the error.

19 Sep 2005 3:19 PM

Cail Young

On 19/9/05 7:28 AM, "John" <John@nospam.com> wrote:

> I haven't seen any comments about stuck pixels which is why I'm
> wondering if:
> (1) I got a rare defective set.

It's rare to have three so soon, but one isn't uncommon.

> Is this stuck pixel defect in the LCD screen itself or is there any
> chance it might be some tiny specks of dust inside the optics that a
> repairman could blow out causing the stuck pixels to go away?

There are no optics in a direct-view LCD set, just a backlight with an LCD
panel in front of it. Pixels (or in your case, subpixels, because they
aren't white) can get 'stuck on', it does happen rather often.

20 Sep 2005 3:29 AM

John

On Tue, 20 Sep 2005 01:19:33 +1000, Cail Young <nospam@anywhere.com>
wrote:

>On 19/9/05 7:28 AM, "John" <John@nospam.com> wrote:
>
>> I haven't seen any comments about stuck pixels which is why I'm
>> wondering if:
>> (1) I got a rare defective set.
>
>It's rare to have three so soon, but one isn't uncommon.

When you say "so soon", do you mean that they typically increase in
number over time? That's a scary thought.

So I could go to a bunch of trouble to exchange my set (which several
people have suggested I do) and if I'm lucky I could get a set without
any stuck pixels, but over time I could still end up with a bunch of
stuck pixels causing the exchange to be in vain?

Would you happen to know of any web sites discussing this subject and
how many stuck pixels one would expect to appear per year?

I guess I'm going to have to read up on the technology behind it to
understand why this happens.

>> Is this stuck pixel defect in the LCD screen itself or is there any
>> chance it might be some tiny specks of dust inside the optics that a
>> repairman could blow out causing the stuck pixels to go away?
>
>There are no optics in a direct-view LCD set, just a backlight with an LCD
>panel in front of it. Pixels (or in your case, subpixels, because they
>aren't white) can get 'stuck on', it does happen rather often.

It's interesting how it's actually several subpixels all of the same
color because they are more like small uniform color "blotches".

20 Sep 2005 9:54 PM

Cail Young

On 20/9/05 1:29 PM, "John" <John@nospam.com> wrote:

> It's interesting how it's actually several subpixels all of the same
> color because they are more like small uniform color "blotches".

That's different. Are you saying you have multiple adjacent pixels that are
gone? That's definitely a replacement candidate.

22 Sep 2005 3:15 PM

John

On Wed, 21 Sep 2005 07:54:59 +1000, Cail Young <nospam@anywhere.com>
wrote:

>On 20/9/05 1:29 PM, "John" <John@nospam.com> wrote:
>
>> It's interesting how it's actually several subpixels all of the same
>> color because they are more like small uniform color "blotches".
>
>That's different. Are you saying you have multiple adjacent pixels that are
>gone? That's definitely a replacement candidate.

When I posted, I hadn't read some long threads at avsforum.com and I
didn't realize the word "blotch" was used to describe another problem.

Apparently there is a "color blotch" problem due to polarization which
makes an overall discoloration depending on what's displayed on the
screen, and then there are stuck pixels which stay constant.

My problems are definitely stuck pixels, but when I say I have a few
of them, each occupies more than what looks like a single pixel up
close. They are uneven and look like they take up maybe 4 or 5
adjacent pixels which is why I called them blotches, but at a distance
of a few feet or more they look like a single pixel, and from 10' or
more I can't see them at all. I still want to exchange the unit, but
I'm up against supply problems plus I was misled (don't know if it was
intentional or unintentional) on what my extended warranty covered
(i.e. bulb replacement), so I'm mad at the store, and I don't know
what will happen.

I'll probably post another message about the warranty issue.

21 Sep 2005 2:34 PM

Dimitrios Tzortzakakis

--
Tzortzakakis Dimitrios
major in electrical engineering, freelance electrician
FH von Iraklion-Kreta, freiberuflicher Elektriker
dimtzort AT otenet DOT gr

Show quote Hide quote

? "John" <John@nospam.com> ?????? ??? ??????
news:432dda2f.3812910285@news.west.cox.net...
> I just got a new Sony KDFE50A10 LCD TV. The very first thing I noticed
> (and it's my only significant gripe) is that it had 3 noticeable
> "stuck pixels" for lack of a better word. In Normal (4:3) mode or when
> the screen is black you don't see them, but when there is picture
> information these 3 spots show up as stuck blue pixels no matter what
> the background color is. One of these spots covers a few adjacent
> pixels. At my normal viewing distance (10') I can't see them, but it's
> one of those things that bothers me because I know they are there and
> they shouldn't be.
>
> Are stuck pixels like this normal on LCD TVs or is this a defect for
> which I should exchange this set?
>

Doesn't that ring a bell?Yes, it's perfectly normal for a LCD or TFT screen
to have dead pixels.That's why some manufacturers give a 0-dead pixel
guarantee, for say, 3 years.I'm always telling to anyone who would care to
listen, that the TFT-LCD technology isn't better than CRT, just because it's
newer.Think of it:in a CRT, you have the cathode rays hitting the dots of
phosphorus and making them light, emitting blue, green, red. The cathode ray
can be easily deflected/accelerated, also manipulated.It's very easy to
construct excellent CRT tubes very cheaply.On the contrary, the LCD/TFT
consists of many pixels, each individually powered and controlled, so the
chances of failure are high, considering the million of pixels making a
screen, while the CRT only fails completely to display, if some of the three
cathode rays fails (blue/green/red) or usually the flyback transformer or
the anode voltage transformer.

didn't use the right words when searching the net about this.
Show quoteHide quote

>
> Is this stuck pixel defect in the LCD screen itself or is there any
> chance it might be some tiny specks of dust inside the optics that a
> repairman could blow out causing the stuck pixels to go away?
>

21 Sep 2005 7:33 PM

JoJo

sony model mentioned is a rear projection not true LCD

Dimitrios Tzortzakakis wrote:
Show quoteHide quote

> --
> Tzortzakakis Dimitrios
> major in electrical engineering, freelance electrician
> FH von Iraklion-Kreta, freiberuflicher Elektriker
> dimtzort AT otenet DOT gr
> ? "John" <John@nospam.com> ?????? ??? ??????
> news:432dda2f.3812910285@news.west.cox.net...
>
>>I just got a new Sony KDFE50A10 LCD TV. The very first thing I noticed
>>(and it's my only significant gripe) is that it had 3 noticeable
>>"stuck pixels" for lack of a better word. In Normal (4:3) mode or when
>>the screen is black you don't see them, but when there is picture
>>information these 3 spots show up as stuck blue pixels no matter what
>>the background color is. One of these spots covers a few adjacent
>>pixels. At my normal viewing distance (10') I can't see them, but it's
>>one of those things that bothers me because I know they are there and
>>they shouldn't be.
>>
>>Are stuck pixels like this normal on LCD TVs or is this a defect for
>>which I should exchange this set?
>>
>
> Doesn't that ring a bell?Yes, it's perfectly normal for a LCD or TFT screen
> to have dead pixels.That's why some manufacturers give a 0-dead pixel
> guarantee, for say, 3 years.I'm always telling to anyone who would care to
> listen, that the TFT-LCD technology isn't better than CRT, just because it's
> newer.Think of it:in a CRT, you have the cathode rays hitting the dots of
> phosphorus and making them light, emitting blue, green, red. The cathode ray
> can be easily deflected/accelerated, also manipulated.It's very easy to
> construct excellent CRT tubes very cheaply.On the contrary, the LCD/TFT
> consists of many pixels, each individually powered and controlled, so the
> chances of failure are high, considering the million of pixels making a
> screen, while the CRT only fails completely to display, if some of the three
> cathode rays fails (blue/green/red) or usually the flyback transformer or
> the anode voltage transformer.
>
>
>
>
>
> didn't use the right words when searching the net about this.
>
>>Is this stuck pixel defect in the LCD screen itself or is there any
>>chance it might be some tiny specks of dust inside the optics that a
>>repairman could blow out causing the stuck pixels to go away?
>>
>
>
>

24 Sep 2005 4:06 AM

Bill Sharpe

JoJo wrote:

> sony model mentioned is a rear projection not true LCD
>

That's probably why each defect looks like more than a single pixel.
I've got one white pixel that is noticeable only on a black screen on my
computer screen. I think of it as having only one bad artifact out of
hundreds of thousands of pixels.

Live with it. Stay ten feet back.

Bill

26 Sep 2005 3:18 PM

John

My replacement set has no dead or stuck pixels, but there are 4 pieces
of dirt sandwiched between pixels that you can see if you look really
closely. At even 3' back you can't see them, so I wouldn't return it
based on that. My only disappointment is the geometry is off a little
near the top... when I put a rectangle pattern the top of each side
goes in about 1/4". I wonder/hope there is a service setting where the
top half can be expanded slightly without changing the bottom (I know
computer monitors often have such an adjustment).

I'm also tempted by seeing a 55" Sony A20 set for $500 more assuming
they are still i nstock. Maybe I should've gotten the bigger set at
$100 per extra sq. inch. Decisions decisions... but either way I'll
either end up with the 50A10 or the 55A20.

On Fri, 23 Sep 2005 21:06:53 -0700, Bill Sharpe
<billsha***@nsadelphia.net> wrote:

Show quoteHide quote

>JoJo wrote:
>> sony model mentioned is a rear projection not true LCD
>>
>That's probably why each defect looks like more than a single pixel.
>I've got one white pixel that is noticeable only on a black screen on my
> computer screen. I think of it as having only one bad artifact out of
>hundreds of thousands of pixels.
>
>Live with it. Stay ten feet back.
>
>Bill