A look into dead pixels- 2007 - BeHardware
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Written by Vincent Alzieu

Published on May 4, 2007

URL: http://www.behardware.com/art/lire/666/


Page 1

Introduction

Introduction
We start off assuming you know what a dead pixel and the ISO norm are. If this isn’t the case, you may first want to go to the next page before reading on.

Two years after our first article on dead pixels, we wanted to come back to the subject, partly to update the information, and also to take a closer look at defective pixels with the manufacturers themselves.

We sent them questionnaires asking them to spell out exactly what their policies are, if they were a little more lenient in practice, and also how many of their screens are affected by this problem.

This is something we wanted to delve into two years ago, but without success. Attitudes have indeed changed since and several manufacturers responded with credible information. We would like to take the opportunity here to thank Acer, Eizo, Iiyama, LaCie and Packard Bell for choosing to be more transparent.


Hyundaï also responded, however, we thought their answers were a little too optimistic.

So, we have something new. Manufacturers have answered about the real risks of dead pixels!
What percentage of screens are affected?
We asked manufacturers as well as a major on-line retailer, whom we promised confidentiality, and all we can say is that this is a significant number. The figures of this “secret” source should be trustworthy and representative.

  • Acer and Iiyama responded : less than 1 % of screens have defects – this includes all types. This means power source defects, etc.
  • LaCie and Packard Bell said : less than 0.05 % of screens have dead pixel problems. LaCie’s response is credible as their products are destined for professionals and are checked. Packard bell seemed to be a little too optimist, in our opinion, for a general public manufacturer...
  • Eizo, who checks their screens one by one before packaging, said : less than 0.01 % of screens are affected by dead pixels.

    Finally, our “mysterious informant” gave a figure of:
  • 3 to 5 % of returns on entry level models, all defects included. Dead pixels only represent 1 %, while the rest are due to backlighting and especially power source defects (for example noisy power supply ).
  • 0.3 % of returns of major brand names are due to dead pixels upon delivery.

    Obviously, they do not have the figures for dead pixels in the long term, because this is no longer their problem. We had to go directly to manufacturers for this info and they only indicate the number of screens that have this defect right out of the packaging. Either way, from our experience, this is quite rare.

    All info seemed rather coherent (except Hyundaï and Packard Bell seemed little too confident) and the real risk of dead pixels appears to be around 0.5 %.
    Should you take an optional dead pixel policy?
    Theoretically, no. A 22 inch screen generally costs around 400 euros. If 1 % are potentially defective, the cost of a fair warranty option should be 0.5 % x 400 = 2 euros. Most often, it’s twenty times this amount that brands ask for in offering this policy.

    Intentions of reassuring the buyer can sometimes go against manufacturers. After screens have been picked through by those who sign up for this option, this could mean that the left over defective ones are for those who don’t take this additional coverage. It can be illogical to believe that we (those who don’t opt for the policy) have more chances of getting a screen with dead pixels in stores.

    In the end, it’s better to have overall policies and particularly, those that are offered by on-line stores. On-line sales are protected by consumer laws (article L. 121-16), which give you seven days after you receive the product to make an exchange or get your money back. The seller cannot apply any penalties and you only have to pay the return postage fee. This is by far the best guarantee against dead pixels.


  • Page 2
    The ISO 13406-2 norm

    A standard norm : The ISO 13406-2
    The evolution from CRT (tube screen) to LCD technology has at least one major problem: dead pixels. Like all industrial products, LCD screens follow several standards. The main ones come from the international organization, ISO, who made such norms as the ISO 9002. For LCD screens there is the 13406-2 and from it comes several screen characteristics; response time (see this article on this subject), viewing angles, contrast ratio, brightness (more on this here ), etc. Based on the fact that a liquid crystal panel can’t be perfect, the ISO 13406-2 also introduced rules regarding defective pixels in relation to screen size.
    What is a dead pixel?
    The norm defines three types of defects.
    Type 1 is for pixels stuck (“hot pixels”) in the “up position” while type 2 is for those stuck in a “low position”. In other words, this corresponds to pixels that remain in white or black regardless of the picture displayed. This may sound alarming, but this is compensated by the brightness of surrounding pixels which reduces this defect to some effect. There is one type of dead pixel left…


    Type 3 concerns sub-pixels. If you take a closer look at your screen you will see that each pixel is actually made of three sub-pixels sitting side by side: one red, green and blue. A type three error designates the malfunctioning of one of these red, green, or blue components. This time the result is a very bothersome red, green or blue dot on your screen, called a “stuck pixel”.

    ISO answered our questions regarding the defect rate for LCD screens. The norm was developed for small screen sizes inferior to 15” intended for use by manufacturers. Since then, however, LCDs are omnipresent, sizes have increased and resolution has changed from 1024 x 768 for the 15" LCD, to 1280 x 1024 for the 17 and 19", to 1600 x 1200 for the 20”, and finally up to 2560x1600 pixels on 30”s.
    What the norm says
    The ISO 13406-2 norm defines 4 classes of screens. The strictest and best one, “class 1”, allows no defects. The worst, “class 4” authorizes up to 1344 pixels and faulty sub-pixels on a 20” screen! Fortunately, no manufacturers use this class and almost all use class 2 to establish their warranties.


    A case in point : BenQ and its FP series (not the T).

    On the FP series, BenQ applies the Class II of the ISO norm. Their 19” monitors are equipped with 1280 x 1024 panels, and thus have 1280 x 1024 = 1,310,720 pixels.

    Type 1 : 2 x 1,310,720 / 1,000,000 = 2.62144 dead pixels tolerated
    Type 2 : 2 x 1,310,720 / 1,000,000 = 2.62144 dead pixels tolerated
    Type 3 : 5 x 1,310,720 / 1,000,000 = 6.5536 dead pixels tolerated

    If we first take type I errors into account this means 2.62144 white pixels are acceptable.
    2 white ones and BenQ doesn’t exchange the screen
    3 whites and we are above the tolerance level and the guarantee comes into play.

    If we continue with this principle, BenQ will make an exchange if you have:
  • 3 white pixels or
  • 3 black pixels, or
  • 7 defective sub-pixels.
    On the other hand, if your screen has two white pixels, two black and six colored, BenQ could reply that they are still within the norm and refuse a return.

    The norm applied to 17, 19, 20, 22, 23, 24, 26, 27, and 30 inches

    Applied to current diagonals, Class II tolerance allows the following errors :


    By default some screens are Class I

    If a screen is ISO 13406 certified, but the manufacturer doesn’t indicate the class, it’s automatically a Class I, or in other words, is guaranteed for zero dead pixels

    Excerpt of the norm :

    ISO 13406-2:2001(F), p39, chapter 7.20, Pixel defects
    It’s agreed that flat panel-type screens are in the Pixel class I concerning defects (refer to 3.4.13 Pixel defects). In the contrary case, the manufacturer must specify the defect Pixel class of the screen.


    Now, let’s move on to what each manufacturer says...


  • Page 3
    Acer

    Acer
    The first manufacturer interviewed gave us the first responses. Attitudes sure have changes since two years ago, when it was unthinkable to ask about defect rates. We tried and hit a wall. Here, Acer’s answers are clear and concise:

    1 – BeH : From how many dead pixels will you replace a LCD screen ? Does your exchange policy match the ISO 13406-II norm?


  • We take returns starting from 2 pixels in the middle or an overall total of 4 defective pixels – no distinction is made between a plain pixel (black or white) or colored sub-pixels (red, green, blue). This goes for all Acer screens up to 26 inches. We don’t have any 27”or 30” monitors.

    BeH note to readers: Acer says that it follows the ISO norm as well as applying its own policy. Actually, the more advantageous of the two is applied to the client’s situation.

    2 – BeH : What percentage of screens is affected by the problem of dead pixels according to you ?

  • Less than 1 % : This percentage corresponds to the total number of defects on our monitors (including power source problems, electronic, etc...).

    3 – BeH: Why not offer a standard zero dead pixels warranty?

  • We prefer to satisfy a larger number of buyers by offering a guarantee that goes further than the ISO 13406-II norm

    4 – BeH : How much would you evaluate the additional cost of a zero dead pixel policy to be ?

  • This is something we are studying at the moment.


  • Page 4
    Apple

    Apple
    Unfortunately, Apple didn’t take the time to respond to our questions. We found their warranty conditions on their website. So much for our questions.

    For dead pixel sources, there are pre- and post-2006.

    Before: everything was resolved case by case and there was no official policy.

    After 2006: the ISO 13406-II became the base for all of their screens, however, it is still recommended that you call Apple if you have a problem, even if it doesn't’t correspond to the norm’s specifications.

    This also applies to iMacs of all diagonals.

    Apple being one of the rare manufacturers to offer screens up to 30” gives us the following full table:


    Once again, this is only indicative and we think that Apple would be understanding if you found 20 dead sub pixels on a 30” right out of the box, or even a 19” or 18”. So, where is the limit? This American manufacturer chooses to be a little vague.


    Page 5
    Asus

    Asus
    A late comer to the LCD market, Asus set itself apart from the competition by adopting a ZBD policy, or Zero Bright Dot. Literally, this means zero bright dead pixels.

    There are actually two conditions to this:

  • Only bright pixels and sub-pixels are covered by the warranty. This means the white, red, green and blue and, therefore, not the black. However, from our experience, the latter are very subtle, less annoying and their effect is minimal.

  • Next, the warranty is valuable “only” for the thirty days after you buy the screen. After this, it falls back to the classic ISO 13406-2. Once again, from experience we can say that dead pixels are starting defects and it’s rare that they appear in the long term.

    Good job Asus! They actually opened a website devoted to explaining this warranty. If only their rivals would follow this initiative...





  • Page 6
    Belinea

    Belinea
    Unfortunately, Maxdata didn’t take the time to answer our questions. We found their warranty conditions on their website. So much for our questions.

    Concerning their dead pixel warranties, it’s very simple. All of their product technical sheets offer the same one, the ISO 13406-II.


    This table is different from the one , which we published two years ago. At that time, Belinea told us they were following a rather original policy, where they would replace the screen if they found over three consecutive dead pixels or 4 throughout the screen, whatever its size. It was better before Belinea took its turn in opting for the ISO norm.


    Page 7
    BenQ

    BenQ
    Unfortunately, BenQ didn't take the time to answer our questions. We found their warranty conditions on their website. So much for our questions. We however found a way to discuss the problem with the manufacturer.



    BenQ remains the last major manufacturer to use the section 3 of the ISO norm for some of its products (the T series, available in Europe but not in the US).

    You can find this out by going on their website (French version). Once this is downloaded, you can find the specific procedure and guidelines for returning a screen with defective pixels.

    There we find (translated from French as we couldn't find the corresponding English document) :

    1. Determining if a pixel is really defective
    • A defective pixel can be declared defective if all of the following criteria are met:
    • Pixels should not change state, this means:
    i. The color doesn’t change
    ii. Brightness doesn’t change
    iii. Contrast doesn’t change

    The defect is permanent, which means:
    o In and out of the operating system (Windows) the problem should persist.
    o The pixel should stay in the same place.
    Note: if all of these criteria are met, the pixel is defined as a defective pixel.

    2. Number of pixels
    Commercial monitors starting from 2005


    If the number of pixels is greater than the authorized number, the monitor can be subject to
    a RMA request.
    In certain cases, an exchange can be possible if there is a single defective pixel.
    For more information contact our Hotline.


    A good point is the part that says, “In certain cases, an exchange can be possible if there is a single defective pixel.” In which cases? This is a mystery and you will have to call the Hotline (available on the website for each country).

    A bad point is that the T series is under a ISO 13406-III type warranty. We recommend you simplify things and not buy one of this series, which are luckily becoming rarer. If by chance, someone gives you one, below you will find its warranty conditions.

    Mostly likely, however, you will have one of the FP series, which is covered by the ISO 13406-2 :


    To summarize, have you and your friends stay away from the “T”.


    Page 8
    Dell

    Dell
    Unfortunately, Dell didn’t take the time to answer our questions. We found their warranty conditions on their website. So much for our questions.

    Dell didn’t respond, but our research on their site (not an easy task as we couldn’t find it in specifications or screen info) suggests that they have the same policy as two years ago.

    In really digging you find on a Dell.com support page :

    During the manufacturing process, it is not uncommon for one or more pixels to be fixed in an unchanging state. The visible result is a fixed pixel that appears as an extremely tiny dark or bright discolored spot.
    In almost every case, these fixed pixels are hard to notice and do not detract from the display quality or usability. A display with 1 to 5 fixed pixels is within the industry standards, and is therefore considered an acceptable display. LCD/Plasma screens that do not meet this industry standard are rarely passed on after manufacturing.


    This is summed up in the following official table:


    On the one hand, the guidelines are advantageous compared to the ISO for larger screens. On the other hand, this makes us a little uneasy when we buy an expensive screen, which Dell does happily offer.

    Actually, we know from experience that Dell’s warranty service is quite understanding. We know of several examples where clients exchanged screens right after they received them after finding backlighting or dead pixel defects.

    It’s just too bad Dell doesn’t offer a more interesting official warranty.


    Page 9
    Eizo

    Eizo
    Eizo is part of the upper crust for screens. They are a recognized worldwide for the quality and reliability of their monitors... even if there are so few users that have these products on their desk tops.

    Another interesting point is that they say they follow the ISO norm, but are known to be accommodating. If the dead pixel is in the middle of the screen, it’s replaced.

    Eizo took the time to respond (we thank them) and they even went as far as giving us the dead pixel defect rates. According to them, less than 0.01 % or less than one screen in 10,000 is subject to this type of problem.

    1 – BeH : From how many dead pixels will you replace a LCD screen ? Does your exchange policy match the ISO 13406-II norm?


    2 – BeH : What percentage of screens is affected by the problem of dead pixels according to you ?

  • Less than 0.01 %

    3 – BeH : Why not offer a standard zero dead pixels warranty ?

  • EIZO not being a panel manufacturer, we use panels that are supplied according to development plans, however, this is in accordance with the ISO 13406-II international norm, which is imposed by panel manufacturers.

    4 – BeH : How much would you evaluate the additional cost of a zero dead pixel policy to be?

  • The additional cost would not be interesting for the client, given the current low risk of detection of this type of defect.

  • Page 10
    Fujitsu-Siemens

    Fujitsu-Siemens
    Fujitsu-Siemens responded to our questionnaire, except to one part, the percentage of screens affected by this problem. Otherwise, this manufacturer is the only one to offer an optional zero dead pixel warranty, which you can sign up for here directly on the website, within 30 days of purchase.

    So in reality, you take your screen out of the box and don’t find a dead pixel. You won’t need this option. Or you have defective pixels and have purchased your screen from a store that will not exchange it for some reason. In this case, you are covered. It isn’t free at 39 euros per year, 59 € for 2 years, and 69 € for 3 years. You will also find on the same page, a warranty for theft or breakage, which is a little more expensive (39/69/89 € for 1/2/3 years). Without this, the screen is covered under classic conditions with replacement after 3 dead black or white pixels or 7 colored sub pixels.

    Obviously, we would prefer the optional warranty to be included, especially given this manufacturer’s urgent recommendations to do so. In fact, we read on their website, There is nothing more annoying than one or two small dots on a screen ! All the more so because manufacturers allow up to five defective pixels before intervening.

    For this reason, we have started the Defective Pixel Warranty, which becomes comes into effect even with one black dot.

    In terms of cost, if you decide to have your screen repaired, this is not under a standard warranty and the whole matrix will have to be replaced (600 € including labor ), or twice the cost of the product. With a very low price, defective pixel insurance (from 39 € to 69 €) you are safe, even for one dead pixel!
    .

    Outside of this guarantee, we have the classic ISO 13406-2.

    1 – BeH : From how many dead pixels will you replace a LCD screen ? Does your exchange policy match the ISO 13406-II norm ?


    2 – BeH : If there is a single defective pixel on the side of the screen, will you replace it ?

  • No

    3 – BeH : If there is a single defective pixel in the middle of the screen will you replace it?

  • No

    4 – BeH : What percentage of screens is affected by the problem of dead pixels according to you ?

  • No response.

    5 – BeH : Why not offer a standard zero dead pixels warranty ?

  • All of our screens are tested once they come off the production line, however, there are often problems due to poor transport. On the other hand, to guarantee them would significantly increase prices and affect their competitiveness on the market.

    6 – BeH : How much would you evaluate the additional cost of a zero dead pixel policy to be?

  • We offer a "0 defective pixel" policy on our service website, to which each client can direct access by internet.

    If clients were ready to pay the price for a “zero defect” product , the “zero defective pixel” warranty would become standard.


  • Page 11
    HP

    HP
    HP started to scare us with their first response on the phone, “HP will not answer the questionnaire”. We were a slightly surprised and had to insist a little to get some answers:

    What? The world’s largest seller and manufacturer of computers and screens that are linked to these computers doesn’t want to comment on its warranty policy?
    Finally, the American giant revised its position and wrote us enthusiastically that they officially follow the ISO 13406-II policy. Unofficially, they sometimes go beyond this and let’s just say that it is the minimum on which they base their policy. After this, it is case by case and without any warranty beyond what is legally required.

    This announcement, however, is in contradiction with what they say (in French) on the main HP website.. There they say that except in four cases, all of their monitory follow the 3-5-5 rule: a max of 3 sub-pixels or bright defective pixels (white or colored), a max of 5 black, or a total of bright + black of 5. This is for all diagonals.


    The only solution is to contact HP if you have a problem.


    Page 12
    Hyundaï

    Hyundaï
    Hyundaï partially responded to our questionnaire. Unfortunately, their answers lacked a bit of clarity and surprised us. For example, they didn’t clearly answer the question of which norm their screens follow.

    In referring to the Hyundaï website, we find in the international version that screens adhere to the ISO 13406-2 norm.


    After this, to the part concerning the percentage of their screens affected, Hyundaï told us : Less than 0.01 %. If such a response can be credible with someone like Eizo, who we know personally verifies each screen before it is packaged, we don’t believe it could be true for Hyundaï. Less than 1 screen in 10,000 that is sold is affected ? At times we have enjoyed their screens, however this seems more like just marketing.


    Page 13
    Iiyama

    Iiyama
    Pronounced, i-i-yama, there are two i’s. After this, the manufacturers' rep wanted to explain the situation, which was a little complex:

    The foundation is the famous norm IEEE13406-2... But in reality the situation is a little different:
    - First of all, we don’t distinguish between sub pixels and pixels, or the color, but rather we simply say defective pixel.

    - If there is a single defective pixel in the middle, there is systematically an exchange on the spot, within 48 hours, and this for the 3 years of the warranty, whatever the type or size of screen.

    - For pixels on the sides, it is a little more complicated. This depends essentially on the size of the screen:
    - A 17 or 19" is covered only if there are more than 3 pixels
    - For larger sizes, there has to be more than 4 pixels

    Also, sometimes our technical service will have the client referred directly to us in the case of large claims.
    Either way, in order to avoid any confusion, we ask for a numeric photograph of the screen to evaluate the discomfort for all requests for exchange.


    Bravo Iiyama !
    Back to the questionnaire, then.

    1 – BeH : From how many dead pixels will you replace a LCD screen ? Does your exchange policy match the ISO 13406-II norm ?


    2 – BeH : If there is a single defective pixel on the side of the screen, will you replace it ?

  • Less than 1 %

    3 – BeH : Why not offer a standard zero dead pixels warranty ?

  • We are in the process of making this decision.

    4 – BeH : How much would you evaluate the additional cost of a zero dead pixel policy to be?

  • We don’t have the info to give you an accurate response.

    Then Iiyama added :

    Our particularity is to not distinguish the type of defective pixel. Also, we always reserve the right to a commercial arbitrage for all claims. Finally, our screens do have an onsite exchange policy for 3 years.


  • Page 14
    Nec

    Nec
    Nec Display Solutions quickly answered our questionnaire. In short, for them it’s the ISO 13406-2 and then they could not respond to the following questions. This is unfortunate, especially from a company that targets for excellence and image professionals, a group that doesn’t tolerate defects too well.

    If we surf their site a little, we find something different than what they told us. There we read in the FAQs (translated from the French website) :

    What do dead pixels mean in liquid crystal displays?

    In manufacturing, millions of transistors are mounted into each liquid crystal screen. Certain manufacturing restrictions sometimes result in dead pixels. A "dead pixel" can be in the form of a contrasted or black dot. A contrasted point is visible when the displayed image is entirely gray. A black dot is visible when the displayed image is entirely red, green, or blue.

    According to our manufacturing norms, up to 10 dead pixels are permitted. However, when they are grouped, we judge this on a case by case basis depending on the missing colors and the distance between pixels.


    Below adds to their official response :



    Page 15
    LaCie

    LaCie
    LaCie has a similar reputation to Eizo’s. LaCie’s advantage is that they are one of the best examples for dead pixel warranties and all of their screens are guaranteed against any black or white pixel. After this there is a small paradox. LaCie says that its products are ISO-13406-2 minimum certified but they filled our table with more lax values for sub pixels than the ISO norm. A mistake?

    1 – BeH : Starting with how many dead pixels will you replace an LCD screen ? Does your exchange policy match the ISO 13406-II norm?


    For LCD 17 and 19"s (1280 x 1024 pixels) :
    We replace the screen from the moment you find a single dead pixel, whether it is black or white, and a max of 8 sub-pixels

    For LCD 20 and 21 format 4/3" (1600 x 1200 pixels) :
    We replace the screen the moment you find a single dead pixel, whether it’s black or white, and a max of 10 sub-pixels (LaCie 321), 9 sub-pixels (LaCie 320)

    LCD 23, 24, 26, 27" (1920 x 1200 pixels) :
    We replace the screen the moment you find a single dead pixel, whether it’s black or white, and a max of 8 sub-pixels overall (LaCie 526)


    2 – BeH : What percentage of screens is affected by the problem of dead pixels according to you ?

  • Less than 0.05 %

    3 – BeH : How much would you evaluate the additional cost of a zero dead pixel policy to be?

  • No response.

  • Page 16
    LG

    LG
    Unfortunately, LG didn’t take the time to answer our questions. We found their warranty conditions on their website. So much for our questions.

    LG didn’t respond, but a small tour of their website showed us that they tightened up their exchange policy.

    In our previous inquiry, they said that exchange was possible starting with 2 black or white pixels for 17 or 19”s if they were in a diameter of 10 cm. Now, this rather original policy is no longer valid. LG has joined the club and follows the ISO 13406-2.




    Page 17
    Packard Bell

    Packard Bell
    If you don’t always find Packard Bell screens in stores, this manufacturer automatically sells many with its central units. And they took the time to answer our questions.

    1 – BeH : From how many dead pixels will you replace a LCD screen ? Does your exchange policy match the ISO 13406-II norm ?


    In the table it looks simple, however the manufacturer sent us more material which complements the ISO norm. It slightly complicates things, but in the end it’s the consumer that benefits:

  • To determine if a LCD screen is defective, follow the steps below. Note that a bad pixel is one that always has the same color no matter what is displayed on the screen:

    1. Count the total number of bad pixels. If there are ten or more, the screen is defective. If there are less than ten, continue with the following step.

    2.Count the number of pixels of the same color. If there are six or more of the same color, the screen is defective. If there are less than six, continue on to the next step.

    3.If two bad pixels are horizontally continuous and they are the same color, the screen is defective. Note that if the pixels are vertically continuous or are not of the same color, the screen is considered OK.
    If you have bad pixels, but they don’t correspond to the descriptions in steps 1, 2 or 3, the screen is OK.


    3 – BeH : What percentage of screens is affected by the problem of dead pixels according to you ?

  • Less than 0.05 %

    4 – BeH : Why not offer a standard zero dead pixels warranty ?

  • No response.

    5 – BeH : How much would you evaluate the additional cost of a zero dead pixel policy?

  • We don’t have the technical expertise to give you an accurate answer.


  • Page 18
    Philips

    Philips
    Philips, who responded to our questionnaire, pointed out that they offer some products in the ISO13406 class 1, which guarantees the user 0 defective pixels in the manufacturing process and in the warranty for 3 years . This is called, « Perfect Panel » and is available on the 17" 170B7CS and 170PES and 19" 190B7CS models. It’s the only one of its type on the market. .

    Besides these screens, it’s complicated... it varies from one screen to another, from one series to the next, etc. Happy reading !

    1 – BeH : From how many dead pixels will you replace a LCD screen ? Does your exchange policy match the ISO 13406-II norm ?


    3 – BeH : What percentage of screens is affected by the problem of dead pixels according to you ?

  • No response.

    4 – BeH : Why not offer a standard zero dead pixels warranty ?

  • It is offered on certain models.

    5 – BeH : How much would you evaluate the additional cost of a zero dead pixel policy?

  • No response.

  • Page 19
    Samsung

    Samsung
    Unfortunately, Samsung didn’t take the time to answer our questions. We found their warranty conditions on their website. So much for our questions.

    Samsung didn’t answer us. On their website, we read that their screens are covered by the ISO 13406-2 warranty, without going into detail. They give the norm and that’s it. This manufacturer, however, does offer two other ways to know more about the norm, (that very few people know about anyway) :

    - in the FAQ section, we find this text :
    Regarding pixel defects, Samsung monitors are conform to the ISO 13406-2 Class 2 norm.
    For more information on this standard, consult the page
    http://www.iso.org/iso/fr/CatalogueDetailPage.CatalogueDetail?CSNUMBER=25670
    . This sends us to an ISO page, which offers its description for 216 Swiss francs. Thanks a lot!

    - another option, this time in the monitor technical sheets , when we click on the “13406-2”, we read :
    The ISO norm 13406 indicates the limit for defective elements for display products, which use flat screens. The maximum number of defective elements varies in function to the class to the product (Class I, II, III, IV). Samsung monitors belong to Class II. For more information, please contact Support Services.. It’s not any clearer, but we hope to actually have a human voice in the end to explain things.

    Translated into figures, this gives us :


    Samsung thus has gone backwards, because two years ago it planned on having a zero dead pixel policy on at least some of its products.


    Page 20
    ViewSonic

    ViewSonic
    ViewSonic is also a model in terms of resolving dead pixel defects. All of their screens are guaranteed against white or black pixels. After this, for colored ones it depends on the type of screen :

    The zero dead pixel guarantee – permanent black or white – is standard for all series.
    The VP series benefits from a zero stuck pixel policy – a red, blue, or green dot on a dark background for up to 28 days after purchase.


    1 – BeH : Starting with how many dead pixels will you replace an LCD screen ? Does your exchange policy match the ISO 13406-II norm ?


    2 – BeH : What percentage of screens is affected by the problem of dead pixels according to you ?

  • No answer.

    3 – BeH : Why not offer a standard zero dead pixels warranty ?

  • Our zero dead pixel warranty – permanent black or white pixels – is standard for all series.
    The VP series additionally benefits from a zero sub pixel warranty – red, blue or green dot on a dark background for up to 28 days after purchase.


    4 – BeH : How much would you evaluate the additional cost of a zero dead pixel policy?

  • No response.

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