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例1[机型]东鹏950[现象]屏显正常,重放光盘无图无声。[分析与检查]试用 CD 盘播放,声音正常,说明故障在 VCD 解压板部分。VCD 解压板最易出故障的元器件一是解压缩芯片CL480,二是晶振。用放大镜仔细观察 CL480的引脚是否有虚焊或脱焊等故障,检查后未发现异常。再检查40.5 MHz 晶振两端电压,比正常值0.9 V 偏差太多,而 CL480芯片工作电压5 V 正常,说明此晶振损坏。[措施]用一只好的晶振替换后,机器故障排除。
Example 1 [Model] Dongpeng 950 [Phenomenon] screen is normal, no disc playback picture silent. [Analysis and Inspection] Trial CD disc playback, the sound is normal, explain the fault in the VCD decompression board part. VCD decompression board is the most troublesome components First, unzip the chip CL480, and second, the crystal. Carefully observe with a magnifying glass CL480 pin whether Weld or de-soldering and other failures, no abnormalities after the inspection. Then check the voltage across the 40.5 MHz crystal oscillator too much deviation from the normal value of 0.9 V, while the CL480 chip operating voltage 5 V normal, indicating that the crystal damage. [Measures] Replace with a good crystal, the machine troubleshooting.