Stuck Pixel Test

Use controlled color fields to identify a pixel or subpixel that stays lit in the wrong color and compare it with a true dead pixel.

Why this test is useful

A tiny point that keeps one color while the background changes may be a stuck subpixel rather than a completely dead pixel. Cycle through white, black and the primary colors. A real pixel anomaly usually behaves consistently at the same physical location while the background changes.

What makes a stuck pixel different

A stuck subpixel often keeps one colour state or behaves incorrectly only when certain colour channels are requested. That is why red, green, blue, white and black are more informative here than simply looking for a dark dot on one bright field.

Do not confuse observation with repair

Changing solid colours is useful for identifying how a stuck subpixel behaves, but the browser cannot electrically repair a transistor or guarantee that rapid flashing will restore it. Avoid pressing, rubbing or repeatedly flashing the panel as a supposed fix, especially when the manufacturer provides its own pixel care guidance.

Map the colour behaviour instead of looking only for a dot

Record what the same point does on red, green and blue. If it blends into one field but becomes the wrong colour on the other two, that pattern gives more information about a stuck subpixel state than its appearance on white alone. Check black as well: a point that remains visibly lit on black belongs to a different observation than a dark point that vanishes into black. The aim is to describe repeatable channel behaviour, not to promise a cure.

Before you start

• Clean the screen first so dust, fingerprints and dried cleaner are not mistaken for a panel defect.
• Start at the brightness you normally use. Extreme brightness can exaggerate some panel behavior and make the result less representative of daily use.
• When you notice a suspicious point or region, remember its exact position and repeat the same location with another pattern.

A reliable way to run the test

1. Cycle through white, black and the primary colors. A real pixel anomaly usually behaves consistently at the same physical location while the background changes.
2. When you notice a suspicious point or region, remember its exact position and repeat the same location with another pattern.
3. A tiny point that keeps one color while the background changes may be a stuck subpixel rather than a completely dead pixel.
4. A fixed bright point is easiest to see on black or very dark gray and may be a hot or stuck pixel.

How to read the result

A tiny point that keeps one color while the background changes may be a stuck subpixel rather than a completely dead pixel. Red, green and blue fields isolate the primary channels. A point that fails only when one channel is required can help narrow the issue to a subpixel. If a mark appears in a system screenshot, the cause may be software or rendered content rather than the physical panel. If it stays fixed on the panel but not in the screenshot, hardware becomes more plausible.

What to do next

• Cycle through white, black and the primary colors. A real pixel anomaly usually behaves consistently at the same physical location while the background changes.
• This test can reveal behavior but it does not repair pixels, backlight pressure, panel uniformity or burn in.
• A browser test does not decide whether a panel is inside a manufacturer tolerance. Use the maker pixel policy or warranty terms for that decision.

What this test cannot prove