采用全国联合设计电路的分立件黑白电视机,笔者曾装、修数百台次,在检修该机型的实践中,有两次维修困难重重,在克服困难的同时,也取得了一些宝贵意见,至今不忘。愿与同行交流,供参考。例1 故障现象:光栅小而暗,行不同步,伴音中有交流哼声. The use of the national joint design circuit of discrete black and white TV, I had installed, repair hundreds of times, in the maintenance of the model practice, there are two difficulties in maintenance, overcoming difficulties, but also made some valuable comments Never forget so far. Is willing to exchange with peers for reference. Example 1 Symptoms: the grating is small and dark, the line is not synchronized, there are hum in the sound.