Dead Pixels

[franster2]

Having just read the Dead Pixel article by Tom has convinced me: I don't think I'll be buying a flat panel monitor for a time. They're a way to expensive for such poor quality. Like Tom said, would you accept that sort of
thing in your automobile . .a crack in the windshield is okay? Well, as long as it's a little one. Ha. When flat panel engineering can produce something that works with out
dead pixels I'll begin reconsidering them as a viable monitor for my desk top. Thanks Tom. Ken in Michigan

 

[edwardz]

I must agree i was exited about an LCD <b>before</b> i read the article. I thought the fact that they didn'T talk about it anymore meant that it was no problem anymore. I remember reading about dead pixels before in tomshardware.com. I was suprised about Vincent saying:

"This is where I should apologize. I was not aware of this defective pixel problem before, but in the future we shall bear it in mind when running tests."

Hello? Did i miss something here? Never talked about it and then oh it's such a big thing I mean, get real. It's getting evident that we don't get good LCD reviews. There's way to much objective content. Other times you get the impression that they're watching their words or trying to please a company. And then you see an article like this that gives you the impression they want to make a scene. You get the impression you can't just rely on these articles to figure out weather to buy one or not anymore.

After reading that article I had just one question:
HOW BAD IS THIS PIXEL PROBLEM???

That's what i wanted to know. I mean a database of manufacturers is great but it's not what i want to know. In fact, that's not what you want to know. See how you're thinking? Evrything you said was negative... It's not all negative.


<font color=green><b> I'm a CyberPhile</b> </font color=green>

 

[franster2]

I don't know how I'd get along with out all the good reviews
on line, in THG, Extreme Tech, and Anand Tech. That Tom's
reviews have slid on this one point doesn't mean that he's not all over it like bees on honey now. Notice how his article challenges the manufacturers. I think they'd better
not pay Tom's Hardware to much lip service. Millions of viewers read his reviews. Tom's is rated one of the best in
the industry. Intel thinks highly of THG. In my estimate, there comes a time for new standards. That's what THG is implementing now.
In the past Tom has reviewed all kinds of parameters for
LCD's. He's just found another. Let's wait and see how the
manufacturers respond to this ultimatum by THG.

 

[GoSharks]

Interesting that Tom’s did not even attempt to ask the U.S. division of Hitachi. Our phone number and e-mail are on our site at Hitachi Displays.com. We are independent from Hitachi Displays Europe, they set their own standards.

Our policy in the U.S. is zero dead pixels and a maximum of 5 dead sub pixels before we will replace a unit.

We get an occasional customer who calls us up and complains but the majority of our customers either gets a good panel or they never notice. I cannot remember ever having to replace a unit for more than 5 dead sub pixels. Can it happen, yes however again this is very rare.

Dead pixels in fact are very rare, in fact I cannot remember ever seeing a dead pixel. Unfortunately dead sub pixels are common. They are even common on digital cameras, projectors and LCD TV’s. Plasma is not immune to dead pixels and in fact the occasional CRT monitor will have a phosphor spot missing that will look just like a dead pixel. So it is not just LCD monitors that have this problem.

Look at aperture grill CRT’s for example. The horizontal damping wires block the light from the phosphor behind them. If your run 1280 x 1024 resolution and the unit has two damping wires you could argue that all aperture grill CRT monitors have 2560 dead pixels.

What Tom also neglects to mention is most resellers have return policies. We at MonitorsDirect.com offer a 30 day return policy on any product. If you don’t like the unit for any reason, including dead pixels you can return it for a refund. Our policy states that you are responsible for shipping one way. In most cases we pay shipping when you buy the product so you would be responsible for return shipping. 17-inch LCD for example only costs $10 - $15 on average to ship so the risk is very low to the consumer.


Jim Witkowski
Chief Hardware Engineer
Hitachi Displays

<A HREF="http://www.monitorsdirect.com" target="_new">MonitorsDirect.com</A>

 

[flamethrower205]

You switch jobs? Congrats.
I do agree about the dead pixel thing- hardly noticeable. I mean a lot of the time people's monitors have dust or fingerprint stains (and thus oil) and water, which make a specific pixel/ region look like dead pixels. It's fine.

Hilbert space is a big place.

 

[Sky_Hacker]

>Interesting that Tom’s did not even attempt to ask the >U.S. division of Hitachi. Our phone number and e-mail are >on our site at Hitachi Displays.com. We are independent >from Hitachi Displays Europe, they set their own standards.

Tom put a a notice in his article for stuff like that, here i'll quote it for you

>"Note to manufacturers:

>If your brand has not been discussed, please send us your >answers right now and we'll update the article.
>If your answers are out of date, please send us your new >criteria and we'll update the article.

>Dead pixels in fact are very rare

perhaps in you LCD's, but i my self have not seen one LCD without at least one (i've seen about 15). but i'm sorry, when i open a lcd monitor package and find a little yellow slip that tries to explain the little green dot that will never go away i cant help but be a little pissed. i cant live without my computer for the shipping time it takes. and i will not buy another monitor simply so i can ship the screen should of been working in the first place. i didnt pay one thousand dollars to have to send it back. and when was the last time a monitor company warned me about this before i bought it?

*sigh* sorry if this seems like a flame, but i think that green dot on my retna makes me more aggressive.

 

[Dyltone]

I have the Dell (BenQ) 20.1" LCD and I don't have any dead pixels or even sub pixels for that matter. I've stared at it from top to bottom and side to side and can't find one. I thought I had one, but then I wiped it off 😉. Anyway, is there a test or a test pattern that would make finding these dead pixels easier?

My .02

 

[flamethrower205]

there's a distinction between a dead pixel and a dead subpixel. Many of the "dead pixels" you see are in fact dead subpixels, ie green or red or blue doesn't work correctly. For a pixel to be dead, all 3 would have to be totally dead (so it's rare). As the size of the panel increases, so does the complexity and cost, and thus probability of dead (sub)pixels. So on a 15" good chance it'll be fine, even on 17". Higher than that tho u'll prolly see a few.

Hilbert space is a big place.

 

[edwardz]

Thank you GoSharks and Flamethrower. You have answerd my question and I now have the psycoligical strength to go out there and get me an LCD screen of my choice.

<font color=green><b> I'm a CyberPhile</b> </font color=green>

 

[edwardz]

You have good points there franster. And i'm sorry if i sounded unthankful in my answer. I was just a little irritated i guess.
I'm looking forward like you to seeing manufacturers respond to this but they might just react by denying the importance of the problem like Mr. GoSharks did. In fact, I myself have 2048 "dead subpixels" on my CRT and still live with it.

<font color=green><b> I'm a CyberPhile</b> </font color=green>

 

[GoSharks]

Flame
No I did not switch jobs. As of January 1 we took over all sales, marketing and logistics of Hitachi Displays U.S.A. I still work for Cornerstone / MonitorsDirect and now Hitachi Displays.

Sky
We have notified Tom’s, we had no idea they where publishing this article, or we would have been happy to give them the information I posted here. They tried to contact Hitachi Europe and again we are not part of that group.

Flame is correct, if you see a green dot, this indicates a dead “SUB” pixel, not a dead pixel. Three adjacent dead sub pixels equals one pixel and having three adjacent sub pixels dead is extremely rare, in fact I have never seen one.

We know dead sub pixels are a nuisance, and the panel manufactures are doing everything they can to increase yields. Remember that on a 17 inch panel for example there is 3.9 Million transistors that all must function perfectly in a space separated by only tenths of a millimeter. LCD panels are essentially a big integrated circuit (IC). Even in the process of making IC’s some do not work, the difference is they can get hundreds of IC’s off of one wafer and the ones that don’t work they throw away. Because LCD’s are so large you get one per wafer and cannot just throw it away. The cost of this would need to be passed on to the end user, this would significantly raise the price of LCD monitors.

Jim Witkowski
Chief Hardware Engineer
MonitorsDirect

<A HREF="http://www.monitorsdirect.com" target="_new">MonitorsDirect.com</A>

 

[Sky_Hacker]

my bad..

 

[tombance]

Go for it. When I first got my LCD I had no dead (sub)pixels. However it looks like I have about 10 now because of the numerous times Ive sneezed on my monitor - yet they still dont bother me. Unless you look really close these things are tiny! And there is also the fact that I can just clean it off

<A HREF="http://service.futuremark.com/compare?2k1=5467618 " target="_new">Almost Breaking 12k!!</A>

 

[flamethrower205]

heheehehe, das what my monitor looks like too, except it's usually's my brothers' fingerprints.

Hilbert space is a big place.

 

[packrfan]

Dyltone-

One of the easiest ways to spot a dead pixel (or sub-pixel) is to display an all-white screen and then look for any defects. You'll then want to follow this same procedure, but with an all black screen. You need to do this because pixel defects, especially the lit variety, will appear and disappear depending on the color displayed on the screen. For example, on the EIZO L675 that I currently use, I have a sub-pixel defect that appears as a blue spot on a dark screen. However, this defect disappears when I use a white screen.

Test patterns will actually make finding a pixel defect more difficult.