With a box of first image good quality video playback, the monitor screen color image and sound signals are normal. In this way, failure may be video recording signal processing or head switch control circuit. Disassemble the machine, put the camera in CAM status, aim the camera shooting scene, camera start/stop button, watch tape is normal, connectors, each in the oscilloscope observation FP5001 {3}, {5}, {8}, {10} feet all have records of FM signal output, record video signal processing circuit is working properly. Pop-up batteries and recorded under the welding head/circuit shielded enclosure, and then insert the battery, electric camera start/stop button, observe IC5001 {12} feet enter H? SW and {13} feet enter H? ASW pulse signal waveform is normal. With a multimeter to check Q5009 base as the low level, normal record to 0. 7 v, replay to 0 v (see chart). Further examination Q5003 collector output of 4. 7 V voltage was lost, check QR5001 base no voltage (normal record of 4. 7 V, replay to 0 V), along the circuit inspection system control microprocessor IC6004 {and} feet (V is the picture? DREC output), a high level 4. 8 v normal, explain IC6004 {and} feet to QR5001 base this piece of open circuit fault lines exist. Careful examination revealed two tiny cracks, the printed circuit with a soldering iron repair welding connecting lines, pour the tape back after record replay, working properly.NKfservice manual download site