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故障现象:该机在放入碟片后,能够转动,但读不出总曲目,然后显示屏显示“NO DISC”。分析检修:首先不放入碟片观察,托盘进入后,激光头有红光射出,亮度基本正常,且物镜也上下做聚焦动作。测CPU(U7)⑦脚电压,发现检索期间电压始终为4.5 V,不发生变化。说明CPU没有接收到碟片识别信号。
Symptom: The machine can turn after putting the disc, but can not read the total track, then the display shows “NO DISC”. Analysis and maintenance: First, do not put the disc observation, the tray into the laser head with red light output, the brightness of the basic normal, and the objective lens up and down to do the focusing action. Measuring CPU (U7) ⑦ pin voltage, found that the voltage during the search is always 4.5 V, does not change. Description CPU did not receive the disc identification signal.