论文部分内容阅读
故障现象:插上电源插头接电源开关后,显示功能无显示,机器无任何反应。分析与检修:现象说明电源电路有故障,卸开机盖。对电源电路进行检查,发现交流保险丝F1已熔断,将其更换后,显示功能恢复正常。测量输出端电压,发现无±5V,该机电源电路图如1所示。由电源变压器第一组桥堆输出的±14V电压间跨接两只串联电容(4700μF/25V),中点接地,组成非稳压±14V直流电压对电路板供电。第二组桥堆正端经滤波电容滤
Symptom: Plug in the power plug connected to the power switch, the display no display, the machine without any reaction. Analysis and Maintenance: Phenomenon Description power supply circuit failure, unloading the lid. Check the power circuit and found that the exchange fuse F1 has blown, the replacement, the display function returned to normal. Measuring the output voltage, found no ± 5V, the machine power circuit shown in Figure 1. Two series capacitors (4700μF / 25V) are connected across the ± 14V voltage output from the first set of bridge transformers of the power transformer. The midpoint is grounded and the unregulated ± 14V DC voltage is used to power the circuit board. The second group of positive bridge filter capacitor filter