What is dead pixel?
A dark fixed pixel differs from a bright or colour-stuck subpixel. Clean the powered-off surface first, then inspect white, black, red, green and blue backgrounds. Check that the mark stays at the same physical location; a screenshot on another device can reveal a software artifact instead. Flashing patterns cannot repair physically dead pixels. Record the observation and verify the exact model’s official warranty policy.
Controlled comparison
Use the native resolution and a comfortable brightness. Keep room lighting stable and disable night colour filters while comparing tones.
Change one setting at a time. Record resolution, refresh rate, connection and overdrive or VRR settings, then repeat the same content.
What the result means
These visual patterns are not laboratory measurements. Confirm repeatable observations in ordinary content. Colour accuracy and pixel response require suitable instruments.