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LCD Screens. Zero Pixel Warranties....

Discussion in 'Hobby Electronics' started by Running Through The Forest, Jul 16, 2004.

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  1. Bloody hell it's like getting blood out of a stone

    In my quest to buy a flat panel screen for my PC I have never heard so much
    double talk. OK didn't shop around much because here in SA there ain't
    an awful lot of decent stores to shop in for computer stuff....

    First port of call was Radio Rentals and they flat out refused to hop on the topic
    of a "zero dead pixels" warranty for any of the LCD stuff they sell.

    Next port of call was a shop in Tea Tree Plaza where I found some more screens
    to look at. Even they couldn't say anything more about pixel warranties.

    Why is it such a touchy topic?

    Surely if the screen has dead pixels it's not fit for the purpose it was intended. so why
    is it so topical?
     
  2. Jackie

    Jackie Guest

    If you have access to APC magazine, just recently they had an issue that
    covered this topic in detail.

    A search on their website may even reveal the article.

    Basically don't be bluffed by stores. If you purchase a unit and it
    develops a dead pixel, you have every right to return it regardless of
    what the seller says!

    Jackie
     
  3. DalienX

    DalienX Guest

    i would consider dead pixels to be coverd in the standard warranty. the
    bit about "defective manufacturing" should it.

    Ive never even seen an lcd screen with a dead pixle, except one on a
    laptop i know had been dropped, and dead pixles were the least of its
    problems..
     
  4. Richard

    Richard Guest

    If manufacturers rejected monitors with at least one dead pixels then
    a lot of monitors would get rejected and the price for what is already
    an expensive item would be a lot higher.
     
  5. Lord-Data

    Lord-Data Guest

    Because its not the retailers problem?
    The specifics of it all is by the manufacturers .. buy from someone with a
    satisfaction policy .. Officeworks, for example, has a 30 day return policy,
    regardless of what the reason .. I'd imagine a lot of others do too ..

    Sony has a high series display line which comes with a 0 dead pixel waranty,
    but of course, you pay for the privilage.

    Like otherwise mentioned, the LCD manurfacturing process is rather
    expensive, and very prone to pixel failures. While a lot of money and time
    has been invested in improving the process, there are always going to be
    undetected failures.. The extra screening processes drive the costs up
    significantly .. so if you want a 100% garuntee of 0 dead pixels, pay for a
    high series Sony monitor (X series?) and be happy ..
     
  6. thegoons

    thegoons Guest

    SOme of the higher-end Sony monitors do have zero dead pixel guarantees.
    Harris Technology website http://www.ht.com.au gives some details in the
    description text for the higher-end Sony monitors about zero dead pixel
    policies.

    However, if you specifically tell a retailer that you specifically require
    your monitor to have zero dead pixels, then for the lifetime of the
    wanrranty you should be able to take it back. In reality, this is going to
    be near impossible, however if you had the patience to follow up with your
    local consumer affairs authority or small claims/consumer affairs
    tribunal/court, then they would
    likely find in your favour if you explained that the goods were "not as
    described" and "unfit for the purpose intended". You had also relied on the
    salesman's professional skills/judgment to offer that product based on your
    request.
     
  7. Hi,

    I have seen LCD's with dead pixels. Cheaper ones. Recent was a 15" ACER with
    bright dot in the middle of the screen.

    Viewsonic used to make V520 and V720 (15" and 17" respectively) with 0 dead
    pixels warranty.
    Samsung is selling monitors with 7-days 0 bad pixels warranty.

    I prefer Mitsubishi monitors and sold quite a few of 15" and 17" ones -- all
    turned out to be free of bad pixels, even so Misthubishi does not
    guarrantees it.

    I own a DV175 -- great monitor. Sold about 5 of this model so far -- all
    were OK.

    Rudolf
     
  8. Krusty

    Krusty Guest

    DICKHEAD
     
  9. DalienX

    DalienX Guest

    acer? cheap? i paid $700 for my 15 inch acer. wouldnt exactly call that
    cheap. oh and mine doesn't have any dead pixels.
     
  10. acer? cheap? i paid $700 for my 15 inch acer. wouldnt exactly call that
    Mitsubishi cost about $30-$40 more. Getting a "cheap" one does necessarily
    mean there will be dead pixels, although chances are higher than with more
    expensive ones.

    BTW, I should have the stock of VERY GOOD LCD monitors soon (I am waiting
    for info from USA). Those wil have AV inputs and picture quality is much
    higher than of normal consumer grade monitors. Price, unfortunately, is
    higher too. I will post more info when I have it.

    Rudolf
     



  11. I shall do a google.


    Do you know which month of APC it was?






    John
     


  12. Actually they've left it up to me to search out the policies for the
    brands that they sell which is quite odd if you ask me..... I am
    buying a BenQ.

    The demo one seemed OK had no bad spots and I will plug this
    one in at the store before I take it home.
     


  13. Well that was mature
     



  14. As I mentioned in another reply it's a very interesting topic this.

    The store has more or less said to me that I should be searching out
    the manufacturers policy on the net which I found rather odd, since if
    I have any problems I will be marching back there with the screen in
    order to fix it.

    Strange policy indeed.
     
  15. Lord-Data

    Lord-Data Guest

    LG L1800P 18" here .. much better pic quality than my old 17" Diamond View
    ... I guess i've gone from a cheapy CRT to a high end LCD, but its a VERY
    nice monitor with brilliant picture quality .. bought this one ex-display
    from work so i know it has no dead pixels (got to thoroughly inspect it
    prior to purchase) .. I think LGs warantee on pixels is > 1 dead pixel in
    center area (so 1 only does not count), or 3 outside center area.. but its
    all good for me ..

    And I do not believe LCDs develop dead pixels .. they are 90% of the time a
    manurfacturing process side effect.. LCDs usually only develop dead pixels
    due to damage.. ie, a major impact or drop.

    Also, most dead pixels people see are not true dead pixels, but dead
    sub-pixels, which often are defined even further in warantys.. a dead
    sub-pixel is usually seen as a pixel that wont go a particular colour, or
    stays a particular colour on certain backgrounds .. ie, when the screen is
    most colours you can't see it, but when its black it stays red, or something
    ... my nokia 6600 has one dead sub pixel .. behaves this way .. when the
    screen around it is black (or i guess, more correctly, when it is meant to
    be black), it glows red .. slightly distracting, but i'm used to it now :)

    It'd be the ones that glow a colour when theyr meant to be white that would
    be the worst .. a single bright red pixel on a white background would be
    really annoying :)
     
  16. What about pixels that stay black and just will not change?

    Wouldn't that be more of a problem especially near the centre?
     
  17. Fred

    Fred Guest

  18. Lord-Data

    Lord-Data Guest

    thats usually an actual "Dead pixel" .. a dead pixel is when a pixel wont do
    anythign ..

    a dad subpixel is when it affects only one of the 3 small pixles that make
    up a pixel ..

    most proper "dead pixels" are black ..

    warantys usually cover 1 or 2 dead pixels, but needs to be 4 or 5 dead sub
    pixels to be equiv..
     
  19. From the BenQ web site

    BenQ Australia

    LCD Monitors: LCD Defect Policy
    ----------------------------------
    Due to the cost of producing LCD panels, panel manufacturers
    have set limits as to how many defective dots (or sub-pixels)
    are deemed to be acceptable for a standard LCD panel. The goal
    in setting such limits is to maintain a reasonable price of the
    panel while minimizing distraction from defective dots.


    What is a Bright and or a Dark Dot?
    ----------------------------------
    A pixel (picture element) consists of one red and one green and
    one blue dot or sub pixel. A standard 15" LCD panel with a resolution
    of 1024 x 768 pixels has a total of 786,432 pixels or 2,359,296 dots.
    17", 18.i" or 19" LCD panels have almost 4 million dots, while a
    20.1" LCD has more than 5.5 million dots.

    Each dot is driven by an individual transistor. If a transistor becomes
    defective, the corresponding dot may be permanently lit (a bright dot)
    or may not light (a dark dot). For a manufacturer to guarantee that all
    LCD panels are totally defect free would lead to a much higher cost of
    manufacture.

    Defective Pixel Specifications

    1. Total Defective Dots
    The specifications for the number of defects that are deemed to be
    acceptable for each size of LCD panel are:

    LCD Panel Size Maximum Number of Maximum Number Total Dots
    Bright Dots Dark Dots (Maximum)
    15"/38.1 cm 2 3 5
    17"/43.2cm 3 4 7
    18.1"/46cm 4 4 9
    19"/48.3cm 4 5 9
    20.1"/51.lcm 5 5 10





    2. No Bright Dots in the Central Area of the LCD Panel.
    -------------------------------------------------------
    The central third (1/3) bright dots area of the BenQ LCD panel is
    as illustrated below, taking up one of the height and width of the
    panel (one ninth of the area). No may occur in this area. * Please
    note that the FP767 ver2 white/red and the FP791 have a no bright
    dot policy for the 1st
    year*

    _________________________________________________________
    | | | |
    | | | |
    | 1/9 | 1/9 | 1/9 |
    | | | |
    |________________|______________________|_______________|
    | | | |
    | | No Bright | |
    | 1/9 | In This | 1/9 |
    | | Area | |
    |________________|______________________|_______________|
    | | | |
    | | | |
    | 1/9 | 1/9 | 1/9 |
    | | | |
    |________________|______________________|_______________|


    * Please note that the FP767 ver2 white/red and the FP791 have a
    no bright dot policy for the 1st year*



    LCD Monitor Pixel Spec. Revision 3, 12’~ March. 2004
     
  20. Alex Gibson

    Alex Gibson Guest

    If you have good eye sight, it might not be a big deal.
    For me(and those with glasses) it is a big deal, using an lcd has completely
    got rid of eyestrain, and if I need to can sit in front of the monitor for
    more than eight hours without
    headaches or other problems.

    Quality ? Don't know I've only ever used Samsung.

    I've been using lcds at home for three years and wouldn't go back.
    They are also great if you don't have much space.

    The Samsung 171MP I've used for nearly three years hasn't got a
    single dead pixel yet.
    The Samsung 171s I have also doesn't have any dead pixels but the screen
    doesn't give as good contrast or brightness as the 171MP.

    Alex
     
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