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I have pixel on my LCD that appears black only on a blue background; it works fine on other colors.

Black LCD Pixel

Is this a "stuck pixel" or "dead pixel"?

Ƭᴇcʜιᴇ007
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Mirkan
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1 Answers1

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Dead.

Stuck is ON, dead is OFF.

Pixels are created from sub-pixels of primary colors, typically red, green, and blue:

enter image description here

The reason the dead spot is visible only when blue is displayed is because it is a blue sub-pixel that is dead. When the background is blue, that is the only color on, and it stands out. When the background is another color, the other sub-pixels reproduce it or it is still bright and absent blue, which is less noticeable.

For example, you can see yellow because it is created from red plus green. A white pixel with a dead blue sub-pixel will produce yellow, which isn't very noticeable in a bright spot that small.

There is a guide at digitaltrends.com for various methods of attempting DIY fixes for stuck or dead pixels - though it must be noted that it's
a) very hit & miss &
b) potentially damaging to the rest of your screen if attempted too enthusiastically.

Tetsujin
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    and why it only appears on blue and works just fine on red , yellow , white , etc? – Mirkan Mar 13 '15 at 17:04
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    @Mirkan: Because it is a blue sub-pixel that is dead. When the background is blue, that is the only color on, and it stands out. When the background is another color, the other sub-pixels reproduce it or it is still bright and absent blue, which is less noticeable. – fixer1234 Mar 13 '15 at 17:13
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    You'd find on white that your dead pixel would actually be yellow [ie, red+green] though it would be hard to spot – Tetsujin Mar 13 '15 at 17:40