论文部分内容阅读
故障现象:开机“三无”,有“吱吱”叫声。分析检修;彩电“三无”故障的“病灶”大都在开关电源和行输出电路(参看图1)。开机有“吱”叫声,说明电源起振工作,分析是电源自激振荡频率未被行脉冲同步,故而引起“吱吱”叫声。电源与行脉冲“失步”的原因,一般是开关电源厚膜电路IC_(801)②脚引入的行回扫脉冲消失或幅值低落所致。如果手头有示波器,可以从
Symptom: boot “three no”, “creak” sound. Analysis and maintenance; color TV “three no” fault “lesions” mostly in the switching power supply and row output circuit (see Figure 1). Boot has a “squeak” sounds, indicating the power supply start-up work, the analysis is the power supply self-excited oscillation frequency is not synchronized pulse, which caused “creak” sounds. Power and line pulse “out of step,” the reason is generally switching power supply thick film circuit IC_ (801) ② feet into the retrace pulse disappears or the amplitude of low. If you have an oscilloscope on hand, you can