According to the above phenomenon, a preliminary judgment is track tracking or cassette tape body caused by bad. Insert replay with box, check the cassette tape, found no abnormalities. With AV cables connect camcorders and color monitor, press the track after tracking "+ / -" button, observe the screen in the middle of the noise still exists, doubt is tape with scratches. In a box of good quality video playback, article found that the noise is still appear in the middle of the screen, the top and bottom edges are green, blue or red, yellow and white ribbon, estimates the noise is caused by video signal loss here. Press the track to track "+ / -" button, after noise does not vary from track to track, the judge fault in video drum. Further observation, found a head near the drum fouling severely, causing cassette tape through the registry can't close to on the surface of magnetic head, make a video head can't cut into the right track on pick up signals, resulting in failure of the phenomenon. In suede leather head rod clean up dirt drum surface after insert replay with box, troubleshooting.js7service manual download site