defective pixel
Technical term used in the context of LCD or other digital displays; refers to a pixel that does not function correctly, often appearing as a stuck or dead pixel.
This monitor has one defective pixel.
Please check the warranty conditions for defective pixels.
Compound of 不良 (defective) and 画素 (pixel). 画素 is a modern coinage from 画 (picture) and 素 (element), equivalent to 'pixel'.