故障现象:录像机在模拟输入状态时,图像的行中心位置发生偏移。 故障现象分析 众所周知,图像信号一行周期为64μs,扫描正程52μs,扫描回程12μs。图像信号起点相对于行消隐脉冲前沿时间为12μs,相对于行同步脉冲前沿时间为10μs,图像信号只有在正程的52μs内出现,才能获得一行正确的图像信号。从本机故障现象上看,图像信号起点相对于行同步脉冲前沿时间已发 Symptom: When the VTR is in the analog input state, the line center position of the image is shifted. Fault phenomenon analysis As we all know, the image signal line cycle of 64μs, scan the right 52μs, scan back 12μs. The beginning of the image signal relative to the line blanking pulse leading edge time of 12μs, relative to the line sync pulse leading edge time of 10μs, the image signal only in the positive 52μs appear in order to obtain a line of correct image signal. From the point of view of the local fault phenomenon, the beginning of the image signal relative to the line sync pulse front time has been sent