Abstract: A car radio has the problem of auto-power-on at zero kilometers and after-sales stage, which will cause battery feeding and other consequences. Starting from the circuit principle of the radio, this paper tests the reason of triggering auto-power-on by means of oscilloscope and other tools, locks the failed electronic components, and makes metallographic slice analysis to find the reason of the failure of the electronic components. According to the failure phenomenon of electronic components, the packaging is further studied, the end factors are investigated one by one, and the unfavorable factors are optimized. The tracking results show that the improved component performance and higher yield significantly reduce the defect rate of the radio and improve customer satisfaction. This paper introduces the radio power supply circuit and analyzes the problem of auto-power-on, which provides some solutions for other on-board electrical faults.

Key words: Car radio; Auto-power-on; Power circuit; Static eliminator; ESD diode leakage current

摘要： 某汽车品牌收音机在零公里和售后阶段均存在自动开机的问题，会造成电瓶馈电等后 果。文章从该收音机电路原理出发，利用示波器等工具测试了触发自动开机的原因，锁定了 失效的电子元件，并对其进行了金相切片分析，找到了电子元件失效的原因。根据电子元件 的失效现象，进一步对其封装进行了研究，对各末端因素进行了逐一排查，对不利因素进行 了优化。跟踪结果表明，元件的性能改善和良率提升，大幅降低了该收音机缺陷率，提升了 客户满意度。文章对收音机电源电路的介绍和自动开机问题的分析方法为其他车载电器类故 障提供了一些解决思路。

关键词: 汽车收音机；自动开机；电源电路；静电抑制器；ESD 管漏电电流