Scan the full field for dead or stuck pixels — tiny dots that stay dark or stay colored. Look for tint shifts: the field should be perfectly uniform edge to edge, with no pink, green or yellow cast. Check for banding near dark corners and any brightness falloff toward the bezels.

Check the red+blue mix and secondary hue accuracy. Run it fullscreen and clean the screen first — dust and smudges masquerade as pixel defects. Dim ambient light so your eyes adapt and faint defects stand out.

Judge black in a fully dark room and white in a bright one — ambient light changes what your eyes can resolve. For warranty claims, photograph the defect with a locked exposure in a dark room so the defect is provably on the panel, not glare.