例1 故障现象:东鹏950型VCD机重放时读碟时间太长,且画面频繁出现“马赛克”和停顿现象。分析检修:打开机盖,先用无水酒精棉球清洁激光头物镜,但无明显效果,用CD唱片试放,声音中断现象同样严重,手动激光头寻迹轨从头至尾滑畅无阻,说明激光头机械运行也正常。再检查激光功率电位器也无异常。由于故障出现无规律,分析电源供电不稳定将会造成电路工作 Example 1 Symptom: Dongpeng 950 VCD player playback time is too long when reading, and the picture appears frequently “mosaic” and pause phenomenon. Analysis and Maintenance: Open the lid, clean the laser head objective with anhydrous alcohol cotton ball first, but no obvious effect, try to release with a CD record, the same sound interruption phenomenon, manual laser tracking track from start to finish smooth, indicating Laser head mechanical operation is also normal. Then check the laser power potentiometer is no exception. Due to irregularities appear, analysis of power supply instability will cause the circuit to work