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例1 故障现象:使用中出现有时不能检索曲目现象。放一段时间后不能放音,但重放指示正常。分析检修:拆开机壳,放入唱片能正常出入盒。重放时,唱片不旋转,但激光头能前后左右作聚焦寻迹动作。从侧面观察物镜无红光反射,测量CXA1081第⑤脚有高低电平变化.说明已送出“CD“开启指令。再测激光驱动管Q_1(2SA952)集电极电压,在放音或停止状态,电平无变化。由于触摸Q_1感觉烫手,更换Q_1后,故障依旧。测量激光二极管,发现已击穿损坏。更换
Example 1 Symptom: Occurred in use sometimes can not retrieve the track phenomenon. Put a period of time can not play, but the playback instructions are normal. Analysis and maintenance: open the case, put the record into the box can be normal. When playback, the record does not rotate, but the laser head can focus around tracing action. There is no red reflection from the side of the objective lens and the level of the ⑤ pin of CXA1081 is measured, indicating that ”CD " ON command has been sent. Re-test laser driver tube Q_1 (2SA952) collector voltage, playback or stop state, the level of no change. As touch Q_1 feel hot, replace Q_1, the fault still. Measure the laser diode and found that the breakdown has been damaged. replace