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例1 机型:NV——L15。 故障现象:磁带进盒后能快进和倒带,但不能重放和记录、也不能出盒。 分析与检修:根据此机故障现象,估计与鼓电机转动有关,因为在装盒或快进倒带时,鼓电机是静止不动的,而只有在重放(记录)或出盒时,鼓电机才被启动,为了证实这一推断,可人为地使机器先进入结露保护状态(用手触摸潮湿传感电阻表面),使鼓电机旋转起来,再在这一状态下进行装盒,这时发现:当主导电机同时转动时,故障即出现。这说明故障不在主电路板,而是由于电源的负载能力下降所致。根据以往经验,应重点检查电源与滤波电路,卸下电源单元盒,去掉屏蔽罩后发现:滤波电容C_1108外层塑壳已脱落,用手触摸,发现电容发热。焊下测试,无充放电现象。用一只100μF/400V电容代换后,机器恢复正常。
Example 1 Model: NV - L15. Symptom: The tape into the box can be fast forward and rewind, but can not replay and record, can not be out of the box. Analysis and Maintenance: According to this machine fault phenomenon, it is estimated that the rotation of the drum motor is concerned because the drum motor is stationary when loading or rewinding, and only when playing back (recording) or removing the drum The motor was started, in order to confirm this inference, can artificially make the machine first into the dew protection state (hand touching the surface of the wet sensing resistor), so that the drum motor is rotated, and then in this state the boxing, which When found: When the dominant motor while turning, the fault that appears. This shows that the fault is not the main circuit board, but due to the power of the load capacity decline. According to past experience, should focus on checking the power supply and filter circuit, remove the power supply unit box, remove the shield and found: C_1108 filter capacitor outer shell has fallen off, touch and found that the capacitor fever. Welding test, no charge and discharge phenomenon. Replacement with a 100μF / 400V capacitor, the machine back to normal.