现象:刚开机时图像、色彩和伴音都正常。十分钟后,图像逐渐模糊不清,但伴音正常。关机后再次开机又重复上述现象。 分析与检修:本故障的发生与开机时间长短有关,且每次出现故障的时间较为固定,据此可判断机内某元件的温度特性不良。故障出现时将预选器调在无节目的位置,仔细观 Phenomenon: just boot up images, color and sound are normal. Ten minutes later, the image gradually blurred, but the sound was normal. Power off again after the boot and repeat the above phenomenon. Analysis and Overhaul: The occurrence of this fault is related to the length of the startup time, and the time of each fault is relatively fixed, so that the temperature characteristics of some components in the machine can be judged badly. When the fault occurs, the preselector is adjusted to the position of no program and the view is carefully observed