Estimate fault in video recording signal processing or head switch control circuit. Disassemble the machine, put the camera in state, a camera shooting scene, press start/stop button, observe the cassette tape is normal, respectively with the oscilloscope observation plug-in FP50013, 5, 8, 10 feet are recorded on video signal output, record video signal processing circuit is working properly. Pop-up batteries, shield under the welding head record/circuit. Then insert the battery and electricity camera start/stop button, observe IC5001 12 feet enter H.S W and 13 feet enter H.S W pulse signal waveform is normal. With a multimeter to check Q5009 base for low level (normal record of 0.7 V, replay to 0 V). Further examination Q5003 set motor without a 4.8 V voltage output; QR5001 base no voltage (normal is 4.7 V, constantly replay at 0 V). Along the circuit inspection system control microprocessor IC600418 feet (V.D REC output) in high level, normal, illustrate IC6004 18 feet to QR5001 base the printing plate open-circuit fault lines exist. Check carefully, this circuit has two tiny cracks, the after repair welding, pour the tape back replay, the machine back to normal.6Q9service manual download site