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本人检修一部使用过程中损坏后,送修理部维修又造成故障的NV-370录像机,整个过程涉及电源、磁鼓组件及其伺服、彩色信号处理、系统控制等电路,按检修次序介绍如下。现象一:接通电源时VTR开关不起作用,该指示灯恒亮(稍暗),显示屏不显示,各操作键失灵。检修:测电源REG 12V(TP1002)只有约5～6V,REG 5V(TP1001)为零。查TP1001对地电阻为零。采取分路断开方法找短路点,发现彩色信号处理二次集成块IC8001已更换过,第(40)脚焊点与集成块背面铝箔接触,而铝箔又与地线接触造成短路。排除短路,REG 5V恢复,REG 12V随之正常,操作键功能恢复。
I overhaul a damage to the use of the Department, sent to the maintenance department has caused the malfunction of NV-370 recorders, the entire process involves the power supply, drum components and servo, color signal processing, system control circuit, according to the maintenance order are as follows. Phenomenon one: Turn on the power when the VTR switch does not work, the indicator light constant (slightly dark), the display does not display, the operation key failure. Overhaul: measure the power REG 12V (TP1002) only about 5 ~ 6V, REG 5V (TP1001) is zero. Check TP1001 to ground resistance is zero. Take shunt disconnect method to find the short circuit point, found that color signal processing IC96 has been replaced by the second, the (40) foot solder joints with the back of the manifold aluminum foil contact, and aluminum foil and ground contact caused by a short circuit. Exclude short-circuit, REG 5V recovery, REG 12V followed normal, the operation key function recovery.