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[例1]万利达N28型,开机后不能读取目录,但进出盒正常。分析检修:打开机壳,放入碟片通电试机,发现主导轴能正常转动,由此判断该机的电源、激光头、聚焦伺服电路正常。因为只有当激光头聚焦正常且有聚焦正常信号(FOK)送到CPU时,CPU才放出指令,开启主轴电机电源。退出碟片,通电观察,发现激光头无径向循迹动作,检查激光头组件,发现循迹线圈一引出端与排线焊点接触不良,重焊后试机恢复正常。 [例2]上海K99型,开机时一切正常,约半小时后图像声音突然消失,但屏显计时显示正常。分析检修:打开机壳观察,当故障现象出现时影碟片转动正常,由此判定该机的数字信号处理,伺服控制电路正常,故障可能在解压板,该机解压板主芯片用的
[Example 1] Malata N28 type, boot can not read the directory, but out of the box normal. Analysis and Maintenance: Open the case, put the disc power test machine and found the capstan can rotate normally, to determine the power of the machine, the laser head, focusing servo circuit is normal. Because only when the laser head and the focus of a normal signal focus (FOK) sent to the CPU, the CPU only issued a command to turn on the spindle motor power. Exit the disc, electricity observation and found no radial radial movement of the laser head, check the laser head assembly and found that the tracking coil leads to a poor contact with the cable soldering joints, re-welding test machine returned to normal. [Example 2] Shanghai K99 type, boot everything is normal, about half an hour after the image suddenly disappears, but the screen shows the normal timing. Analysis and Maintenance: Open the case observation, when the failure phenomenon occurs when the disc rotation is normal, which determine the machine’s digital signal processing, servo control circuit is normal, the fault may be in the decompression board, the aircraft decompression board with the main chip