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[例1]开机三无。测C807两端如有300V电压,则故障原因大多为R803(56kΩ/3W)开路,导致开关电源停振,无输出。 [例2]无光栅,有轻微“嘶嘶”声。此故障多为R409(6.8kΩ/3W)或R416(2kΩ/3W)开路,导致行输出级不工作所致。 [例3]无光栅,但伴音正常。若故障时测12V稳压管Q407的e极电压为8V,则故障原因为Q407(2SC495)质量变劣。更换新件后机器工作正常。 [例4]无图像,噪波点正常。这时若测高频头TU无
[Example 1] boot three no. Measured C807 both ends if 300V voltage, the cause of the malfunction are mostly R803 (56kΩ / 3W) open circuit, leading to switching power supply stop vibration, no output. [Example 2] No grating, slight “hissing” sound. This fault is mostly R409 (6.8kΩ / 3W) or R416 (2kΩ / 3W) open circuit, resulting in row output stage does not work. [Example 3] No grating, but the sound is normal. If the fault is measured 12V regulator Q407 e pole voltage is 8V, then the reason for the failure Q407 (2SC495) quality deterioration. After replacing the new piece of equipment is working properly. [Example 4] No image, normal noise point. At this time if the TU tuner without head