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故障现象:能正常搜索自动存台(手动可搜索、可存储),但预置开关S615置“正常”(即NORMAL)状态时,图声跑得无影无踪,屏上只有雪花点。再把S615置“预置”(即PRESET)状态,图声恢复正常。反复将S615上下拨动,机器重复上述现象。遂又转换频道,发现用户原来在15号节目中也存有十频道节目,当S615置“预置”状态时,出现情况与上述刚好相反,即图声消失。分析与检修:鉴于上述情况,初步确定是AFC(或AFT)频率发生偏移。将AFC(AFT)中周T103做轻微调动,重复上述步骤,观其变化,故障依旧。然后配合调
Symptom: can automatically search for automatic storage platform (manually searchable, can be stored), but the preset switch S615 set “normal” (ie NORMAL) state, the sound of the sound ran without a trace, the screen only snowflakes point. Then S615 home “preset” (ie PRESET) state, the sound returned to normal. S615 repeatedly dial up and down, the machine repeat the above phenomenon. And then change the channel and found that the user had in the original No. 15 program also has ten channels show, when S615 home “preset” state, the situation just the opposite and the above, that sound disappeared. Analysis and Maintenance: In view of the above situation, it is initially determined that AFC (or AFT) frequency offset. AFC (AFT) in the week T103 do a slight transfer, repeat the above steps, view the changes, the fault still. Then with tune