故障现象:能正常开机,但按选曲播放键时,机内发出“吱吱”声,共两声,而后,数码显示器无显示,所有按键功能失灵。有时一切正常,正常时,无“吱吱”声。检修过程:开盖观察,发现故障出现时碟片没有转动,并伴有“吱吱”声,如碟片能转动则一切正常。该机已使用4年有余,分析可能是主电机因缺油或碳刷不良造成起动不良,使机器进入保护状态。向电机轴加少 Symptom: Normal boot, but press the play button, the machine issued a “creak” sound, a total of two, then the digital display no display, all key functions failed. Sometimes everything is normal, normal, no “creak” sound. Maintenance process: open lid observation found that the disc does not turn when the fault occurs, accompanied by “creak” sound, such as the disc can turn everything is normal. The machine has been used for more than 4 years, the analysis may be due to lack of oil or poor brush starter bad start, the machine into the protection state. Add less motor shaft