pixel defect; dead pixel; stuck pixel
Technical term for a defective pixel on an LCD or similar display; often used in the context of quality checks for monitors, TVs, and smartphone screens. Compare with ドット抜け, which is sometimes used interchangeably.
See also: ドット抜け
I found a pixel defect on the new monitor, so I had it replaced.
Even a single dead pixel can ruin the impression of the whole screen.
Compound of ドット (dot, pixel) and 落ち (fall, drop, defect), literally 'dot defect'. The term likely arose from the visual effect of a pixel appearing to have 'fallen out' or failed.