一则:开机后电视屏幕显示无电视信号产生该故障的主要原因有:一是有线电视的电缆进线与机顶盒连接不好;二是调谐器供电不正常或调谐器损坏;三是解调器或传输流解复用器损坏。可用示波器分别检测解调器、解复用器等电路的输出数据、时钟、同步等信号,可查明故障原因。需注意的是:如用户欠交收视维护费,也可能收不到电视信号, A: The boot screen after the television signal without television The main reasons for the failure are: First, cable cable into the line with the set-top box is not good; Second, the tuner is not normal power supply or tuner damage; Third, the demodulator Or transport stream demultiplexer damaged. Oscilloscope available separately detect demodulator, demultiplexer and other circuit output data, clock, synchronization and other signals, to identify the cause of the malfunction. It should be noted that: If you owe pay TV maintenance fees, may not receive the television signal,