高士达ＴＰ一９２０放像机特殊故障检修一例故障现象：快进、倒带正常，重放数秒后自动停机保护。分析与检修：笔者对多台单放机同样故障进行检修，发现都是由于收带盘旋转传感器检测电路发生故障引起。该电路主要由收带盘下的光敏组件（型号“１Ａ”）与大板上的开关管Ｑ... High Top TP-920 a special video playback troubleshooting example Symptom: Fast forward, rewind normal, replay automatically shut down after a few seconds to protect. Analysis and Overhaul: The author of more than one single put the same fault repair machine and found that are due to the closing plate rotation sensor detection circuit caused the malfunction. The circuit consists of a photosensitive assembly under the take-up reel (type “1A”) and the switch on the board Q ...