故障现象: 接收电视节目时,荧屏上有光栅,但看不到图象,也听不到伴音。分析检修: 当出现以上故障时,可能有两种情况:其一,光栅上有雪花状噪声点出现,扬声器中有噪声,但是收不到图象和伴音。这说明故障源位于天线系统及调谐器电路上。初步判断方法可用电笔放置在天线插孔处,将铜轴芯线及屏 Symptom: When you receive a TV program, there is a raster on the screen, but you can not see the picture and you can not hear the sound. Analysis and maintenance: When the above failure occurs, there may be two situations: First, there is a snowflake on the grating noise point, there is noise in the speaker, but can not receive images and sound. This shows that the source of the fault is located on the antenna system and on the tuner circuit. The initial method can be used to determine the pen placed in the antenna jack, the copper shaft and screen