论文部分内容阅读
接触不良的故障往往难以寻找。以笔者排除六例这类故障的实例介绍给读者,供参考。 例一:珠海组装的日立HT-CD-529Z彩电,用户经常靠拍打外壳维持正常收看。开机检查发现电源开关(POWER)接通,电源指示灯能亮,电源按钮按下后,交流220伏能加到整流桥。而且行输出管集电极也得到了+103伏电压。但声、光、像皆无,后查行推动管Q402集电极电压为零伏。经查是开关变压器⑦脚焊点熔化(比较明显)与印刷线路板接触不实所致。
Poor contact is often difficult to find fault. I exclude six examples of such failures introduced to the reader for reference. Example 1: Hitachi assembled Hitachi HT-CD-529Z color TV, the user often by flapping the shell to maintain normal viewing. Power-on inspection found that the power switch (POWER) connected to the power indicator light, press the power button, the exchange of 220 volts can be added to the rectifier bridge. And row output tube collector has also been +103 volts. But the sound, light, like nothing, after the search line to promote the tube Q402 collector voltage is zero volts. The investigation is the switch transformer ⑦ feet solder melting (more obvious) and printed circuit board contact is not true.