彩电“吱吱”声故障较为常见,下面以松下TC—217机芯为例,谈谈彩电“吱吱”声产生的原因及判断方法和检修实例(见图1)。一、产生“吱吱”声故障的四种主要原因 1.滤波电容器开路:滤波电容C817开路将导致开关稳压器输出电压不稳定,且纹波增加,因此图像呈S型扭带且有黑横条,伴音出现交流声。此时T801还会发出“吱吱”声。 2.行频脉冲失控:行频同步脉冲来自行输出变压器,经过R806、D805来控制电源块STR50213—M的 TV “creak” sound more common fault, the following Panasonic Mocas TC-217 movement as an example, talk about the color TV “creak” sound causes and determine the method and maintenance example (Figure 1). First, there are four main causes of “creak” sound failure 1. Filter capacitor open circuit: the filter capacitor C817 open circuit will result in unstable switching regulator output voltage, and ripple increases, so the image was S-shaped twisted band and black Cross bar, accompanied by sound exchanges. At this point T801 will issue a “creak” sound. 2. Line frequency pulse out of control: line frequency sync pulse from the output transformer, after R806, D805 to control the power block STR50213-M