Dead pixel or not?

Discussion in 'Mac Accessories' started by coldwaves, Apr 26, 2013.

  1. coldwaves macrumors regular

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    May 30, 2011
    #1
    I bought a used 24 inch cinema display a few weeks ago. I just noticed maybe two dead pixels (adjacent to each other) on the left side of the screen last night. I first thought it is just dust so I wipe off the screen. But it is still there. I open the glass cover and clean the inside of the glass as well as the surface of the LED panel. The dead pixel is still there. It disappear in black screen but is visible in all other colors. It is hard to say what color it is but it appears that it changes color when you look at different angle. Also, it seems the pixel moves when you look at it from different angles. I put the mouse pointer right under the pixel. Then if I move my head right to left, I can see the pixel move location compared to the pointer. This is rather confusing to me. Is it really a dead pixel or is it dirt somewhere? Thank you for your help!
     
  2. justperry macrumors 604

    justperry

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    #2
    Take a screenshot, if it is not on the screenshot and you cleaned the LCD panel it is/are dead pixel(s).
     
  3. skorpien macrumors 68020

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    Jan 14, 2008
    #3
    If it's moving when you move your head, it sounds like it could be a flaw in the glass. Have you tried turning it on with the glass removed? That would show whether they're actually dead pixels on the LCD panel or if it's due to something else in the glass.
     
  4. coldwaves thread starter macrumors regular

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    #4
    Thank you! Yes, it is moving. I put my mouse pointer right on the pixels. Since the mouse pointer is black, I cannot see it in that angle. But if I move around, I can see the "dead pixels" on the side of the mouse. This makes me feel it is potentially a dirt or scratch on the glass. But I use a flash light to exam the glass carefully when the display is off and I cannot see anything there. I remember the "dead pixels" are still there when I took of the glass cover when the display is on but I am not 100% sure my memory is correct. The fact that it is moving and it appears without the glass cover makes me very confusing. I will look at it again when I got home this evening.
     
  5. coldwaves thread starter macrumors regular

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    #5
    Thank you! It is not on the screenshot and I clean the glass several times. This seems to suggest that it is a dead pixel. But it also moves when I look at it from different angle. Is it possible that a dead pixel will appear to move when you look at it from different angle?
     
  6. coldwaves thread starter macrumors regular

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    #6
    I took of the glass cover and the dead pixels are still there. So I assume it is actually dead pixels. I took a picture of the pixels. It seems like it is not completely dark but just darker than the surrounding. Also, it seems three pixels are in trouble.
     

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  7. justperry, Apr 26, 2013
    Last edited: Apr 26, 2013

    justperry macrumors 604

    justperry

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    #7
    They don't seem 100% defect to me, you can still see them lighting up a bit, looks like a dark spot to me.
    Down below is yours magnified and there taken from google images, you can clearly see the difference.
    Your blue pixels are not affected at all, only the red and more so the green.

    [​IMG]

    [​IMG]

    [​IMG]
     

    Attached Files:

  8. coldwaves thread starter macrumors regular

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    #8
    I feel the same way. It does not seem to be typical dead pixels as I can still see them light up. Also, without zooming in, the spot does not appear black in a white background. It feels cyan or magenta depends on what angles you look at it. Do you think this can be fixed or not?
     
  9. justperry macrumors 604

    justperry

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    #9
    I know from years ago people would use a test program to "unstuck" frozen pixels, it is more or less an app which changes colours quickly, now, I don't know if this would help here, might try.

    There is some info on stuck pixels here:
    http://en.wikipedia.org/wiki/Defective_pixel
     
  10. coldwaves thread starter macrumors regular

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    May 30, 2011
    #10
    Thank you! I am not sure whether mine are stuck pixels or dead pixels. It seems like stuck pixels often show up as a certain color in completely black screen. But mine disappear in total black background but visible in all other colors. Also, it seems to move when I look at it in different angles. So it feels more like a dust particle. I open the glass cover and the spot is still there. So if it is indeed a trapped particle, it is probably between LCD layers. I tried to lightly tap the area but it does not move the spot at all.

    Anyway, it does not hurt to try the software. I will just run those for a few hours to see whether it helps or not. Report back later!
     
  11. justperry macrumors 604

    justperry

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    #11
    The reason they appear to change while looking at a different angle is two folded, one, because the glass and LCD are relatively far apart, the other one is that your panel does not seem to have a wide angle view.
     
  12. coldwaves thread starter macrumors regular

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    #12
    It is moving compared to the mouse pointer, not a fix spot in the glass cover. I put the mouse pointer right under the spot but it seems to move to the left when I look at it from left or right when I look at it from right. This is confusing to me. It seems to be counterintuitive.
     
  13. justperry macrumors 604

    justperry

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    #13
    This almost indicated the spot is in front of the pixels, not the pixels themselves.
     
  14. coldwaves thread starter macrumors regular

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    May 30, 2011
    #14
    This makes sense. It seems to be something inside the LED panel. It is still there after taking off the front glass panel. I gently wipe the LED panel directly and it is still there. I run the software where you flash color in the affected area and it does not help. I guess I will just live with it and see if it goes away itself. It is not a big dot and is not obvious unless it is on a totally white background. So I guess it is what it is. Hope it fixes itself some time.
     
  15. justperry macrumors 604

    justperry

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    #15
    I have an old Powerbook, it has a soft LCD display, you don't need to be super gentle with it, it can stand a bit of pressure.

    It wouldn't bother me as well, it already an older mac and if it is not in the middle of the display it's not that bad.
    Now, if it was a brand new rMBP I would be fuming.;)
     
  16. coldwaves thread starter macrumors regular

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    #16
    I agree. I got this 24 inch cinema display from Ebay and I believe it was bought in 08. Couple of dead pixels for a 5 year old display are acceptable for me. Plus it is not right in the center. I will just live with it. Thank you for all of your suggestions!
     
  17. mm201 macrumors regular

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