论文部分内容阅读
实例10 一台长虹C2919P型大屏幕彩电,出现开机“三无”故障。分析与检修:开盖后首先进行外观检查,发现保险丝F801(T4 A/250V)管内发黑,已烧断,说明后级电路或元件存在短路现象。用万用表电阻档测量桥式整流、滤波输出端的电阻值仅有1.5Ω,接近短路。采用开路法,逐个焊脱该输出端并联元件以判定故障点。当断开滤波电容C809(560μF/450V)时,短路故障消除。可见C809已被击穿短路(见图18所示)。
Example 10 Changhong C2919P large screen color TV, there boot “three no” fault. Analysis and Overhaul: After the appearance of the first open lid inspection and found fuse F801 (T4 A / 250V) tube black, has been blown, indicating a short circuit or component circuit. With multimeter resistance bridge measurement bridge rectifier, filter output resistance of only 1.5Ω, close to short circuit. Using open circuit, one by one soldering the output parallel components to determine the point of failure. The short circuit fault is eliminated when the C809 filter capacitor (560μF / 450V) is disconnected. It can be seen C809 has been short-circuit breakdown (see Figure 18).