了解在线测试仪的读者,均知道有这么一句行话。“在线测试时不通过的芯片不一定是损坏的;测试通过的芯片一定是没有损坏的。”它的解释为,如器件受在线影响或抗干扰时,结果可能不通过,对此不难理解。那么,是否损坏的芯片在进行测试时,均会得出“不通过”呢?回答确实不能肯定。笔者与同行均遇到过,明明芯片已损坏了(确切地说换上这个芯片板子就不工作了),但测试结果是通过的。权威解释为这是测试仪自身工作原理(后驱动技术)所致。故此我们不能过分依赖在线测试仪(尽管各厂家宣传的很玄)的作用,否则将使维修电路板的工作误入歧途。
维修技巧之二
在无任何原理图状况下要对一块比较陌生的电路板进行维修,以往的所谓“经验”就难有作为,尽管硬件功底深厚的人对维修充满信心,但如果方法不当,工作起来照样事倍功半。那么,怎样做才能提高维修效呢?根据我公司进口设备维修中心统计出来的资料,应遵循以下几个步骤、按顺序有条不紊的进行。
方法一:先看后量
使用工具:万用表、放大镜
当手拿一块待修的电路板,良好的习惯首先是应对其进行目测,必要时还要借助放大镜,看什么呢?
主要看
厦门盈亦自动化科技有限公司
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