Brief signal loss caused by a tape head clog, defect in the tape, debris, or other feature that causes an increase in the head-to tape spacing.
A dropout can also be caused by missing magnetic material. A video dropout generally appears as a white spot or streak on the video monitor. When several video dropouts occur per frame, the TV monitor will appear snowy. The frequent appearance of dropouts on playback is an indication that the tape or recorder is contaminated with debris and/or that the tape binder is deteriorating.
Video: Device for concealment of small erroneous fragments of video (drop-outs), e. g. errors produced because of defects, dirt or wear in magnetic recording media. Once detected these erroneous fragments are replaced by non-corrupted signal from spatially or temporally adjacent areas of TV picture.