机型:莺歌牌145—V 现象:有杂音、无光栅。分析:此现象说明故障主要在行扫描部分,多半是因无中、高压导致无光。检修:测电源+18V、+12V电压正常,而行输出管6BG_5c极为+12V,据此可确定为行停振所致,但测6BG_4、6BG_5、6BG_6均正常,行频线圈及电容也完好,换行输出变压器也无效,拆换了大部分行扫描有关元 Model: Ying song card 145-V phenomenon: a noise, no grating. Analysis: This phenomenon shows that the main part of the fault line scan, mostly due to no medium and high pressure led to no light. Overhaul: measure the power + 18V, + 12V voltage is normal, and the output tube 6BG_5c very + 12V, which can be identified as the line stop vibration caused, but measured 6BG_4,6BG_5,6BG_6 are normal, line frequency coil and capacitor are intact, Line output transformer is also invalid, replaced most of the line scan related elements