Clean before testing
Turn the screen off and clean it using the maker’s recommended method. Dust and dried marks can look exactly like pixel defects.
Use five solid colors
Open the fullscreen dead pixel test. Check black for bright points, white for dark points, then red, green, and blue for subpixel faults.
Verify suspicious points
Change colors and viewing distance. A mark on the surface may shift in appearance, while a panel pixel stays aligned with the pixel grid. Do not press or rub the panel.
Check the policy
Display makers use different pixel-defect policies. Record the position and appearance, then consult the warranty or retailer return terms.