(1)如果显像管灯丝亮,可以说明开关电源和行扫描电路工作正常,此时可重点检查亮度电路、视放电路或显像管供电电路;如果显像管的灯丝不亮,说明故障在开关电源和行扫描电路中。(2)将亮度电位器开到最大的位置,然后在关机时观察屏幕有无闪光或是亮点出现,若有说明机器的行扫描电 (1) If the tube lamp is bright, it can be shown that the switching power supply and the line scanning circuit work properly, this time can focus on the brightness circuit, video circuit or tube power supply circuit; if the tube filament is not lit, indicating the failure of the switching power supply and line scan Circuit. (2) The brightness potentiometer open to the maximum position, and then watch off the screen when there is no flash or bright spot appears, if there is line scanning machine description