Causes of flyback lines, one is a blanking circuit failure, make field blanking signal not to tube; 2 it is abnormal tube power supply circuit, make the blanking signal to by the electron beam; Third, tube failure. ZV8service manual download site
 ZV8service manual download site
Blanking flyback circuit failure to produce line is white, the image brightness and grating. Abnormal tube power supply circuit produces flyback line or at the same time accompanied by partial color, flyback lines with color, or brightness is too bright, image becomes weak, and so on. Tube failure is extremely, extremely. It will also produce brightness changes, lack of color, partial color, flyback lines with color, image becomes weak, such as fuzzy fault. ZV8service manual download site
(1) after startup screen appears to be covered with white flyback line, the image is normal, observe the screen brightness is normal, no partial color. So should check mainly blanking circuit. ZV8service manual download site
(2) use oscilloscope test put board Y blanking signal input terminals in the luminance signal lack of field. Measuring decoding block IC501 attending foot line only blanking signal waveform. Scanning measurement circuit IC701 pet-name ruby foot field blanking waveform is normal. To show that the fault IC701 pet-name ruby feet to 18 feet IC501 between circuits. ZV8service manual download site
(3) check R606, D601 found D601 open circuit, fault elimination after change the new diode.ZV8service manual download site