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例1 故障现象:通电后有电源功能显示,碟盘出入自如,但无法进入播放状态。分析与检修:磁盘不能播放,怀疑激光头不清洁或者电源不正常。打开机盖,对激光头进行检查,发现激光头很清洁,无脏污,检查各路电源供电也未发现明显故障。通电检查,发现光头不能上下移动;高度、倾斜电机不转动。此时,按重放键和数字选曲键功能显示正常。故怀疑故障可能出在电源电路;高度伺服和倾斜伺服部分有关电路,见图1所示。通过对该部分电路进行分析后,为确定故障部位,测量电源供电电压±12V、±5V,结果均正常,对高度电机和倾斜电机及有关驱动电路进行仔细检查也没发现问题。考虑到该机伺服系统为闭环系统,故怀疑系统控制电路有问题,检查微处理器IX2082AF的⑤脚电压为4.6V高电平,此时按播放键后变为低电平,说明微处理器工作基本正常。
Example 1 Symptom: After power on the power function shows that the disk easily accessible, but can not enter the playback state. Analysis and Maintenance: Disk can not play, doubt the laser head is not clean or the power is not normal. Open the lid, the laser head inspection and found that the laser head is very clean, no dirt, check the power supply of various roads did not find any obvious failure. Power check, found that the optical head can not move up and down; height, tilt motor does not rotate. At this point, press the play button and the number of selections key function is displayed properly. It is suspected that the fault may be in the power supply circuit; high servo and tilt servo part of the circuit, shown in Figure 1. Through the analysis of the part of the circuit, in order to determine the fault location, measuring the power supply voltage ± 12V, ± 5V, the results are normal, the height of the motor and the tilt motor and the drive circuit to conduct a careful examination found no problem. Taking into account the aircraft servo system is a closed-loop system, it is suspected system control circuit problems, check the microprocessor IX2082AF ⑤ pin voltage is 4.6V high, then press the play button to go low, indicating that the microprocessor Work is basically normal.