Color Channel Test

Check red, green and blue channels separately so a failed or inconsistent subpixel is easier to isolate.

Why this test is useful

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. Cycle through white, black and the primary colors. A real pixel anomaly usually behaves consistently at the same physical location while the background changes.

Why channel testing is a different job

This test is not primarily looking for one dead or stuck point. It deliberately drives red, green and blue channels separately so you can compare channel uniformity, isolate a colour specific response, and see whether a suspicious point changes when a particular subpixel channel is requested.

Before you start

• Clean the screen first so dust, fingerprints and dried cleaner are not mistaken for a panel defect.
• Temporarily disable Night Light, reading modes and strong color filters when the goal is to compare channels or neutral tones.
• Start at the brightness you normally use. Extreme brightness can exaggerate some panel behavior and make the result less representative of daily use.

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. 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.
3. Inspect the whole panel in an ordered path from one corner to the other rather than staring only at the center.
4. When you notice a suspicious point or region, remember its exact position and repeat the same location with another pattern.

How to read the result

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. A tiny point that keeps one color while the background changes may be a stuck subpixel rather than a completely dead pixel. 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.
• 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.
• 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