世界热推荐:液晶显示器花屏故障怎么排除?液晶显示器花屏如何维修?
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最近小编看到大家都在讨论液晶显示器花屏故障要如何排除相关的事情,对此呢小编也是非常的感应兴趣,那么这件事究竟是怎么发生的呢?具体又是怎么回事呢?下面就是小编搜索到的关于液晶显示器花屏故障要如何排除事件的相关信息,我们一起来看一下吧!
液晶显示器的花屏问题.也是经常发生的。
故障现象:年初朋友更换了一台15英寸液晶显示器,型号是AOC LM-500,一直使用很正常。但刚刚过了半年时间,这台液晶显示器即出现了故障,具体表现为:只要启动或重启电脑,就会出现近似“花屏”的故障现象,给人的感觉就好像有高频电磁干扰一样,屏幕上的字迹非常模糊且呈锯齿状。当进入了Win98SE系统后,偶尔也会出现这种故障现象,但持续的时间很短且不太明显,绝大部分时间屏幕显示是正常的。
故障检查:笔者首先更换了一块显卡,发现故障依旧。接着用一台工作正常的17英寸CRT纯平显示器作替换排除试验,并没有出现类似故障。
液晶显示器故障原理分析:数字接口(DVI)本来是液晶显示器显示的最佳接口。但是显卡厂商出于成本考虑,显卡上一般没有数字接口,而通过内部的数字/模拟转换电路与显卡的VGA接口相连接。这种连接形式虽然解决了信号匹配的问题,但它又带来了容易受到干扰而出现失真的问题。究其原因,主要是因为液晶显示器本身的时钟频率很难与输入模拟信号的时钟频率保持百分之百的同步,特别是在模拟同步信号频率不断变化的时候,如果此时液晶显示器的同步电路,或者是与显卡同步信号连接的传输线路出现了短路、接触不良等问题,而不能及时调整跟进以保持必要的同步关系的话,就会出现本文中遇到的启动显示异常,而进入系统后又显示正常的奇怪故障现象。
据此,笔者判断故障点很可能是在液晶显示器内部的同步电路,或者是连接接口插针以及传输电缆之上。
故障解决:考虑到液晶显示器内部同步控制电路一般都是设置在一块集成电路的内部,且集成电路损坏的可能性微乎其微。于是笔者就将检查的重点放在接口插针、传输电缆以及同步电路的可调整元件之上。
首先将液晶显示器的外壳拆开,露出内部的连接电缆,用数字万用表的通、断检查蜂鸣挡,逐个检查连接插针与对应线缆的导通情况,没发现任何断路、短路等物理连接性问题。接着沿电缆连接线的走向,找到印刷电路板上的输入控制电路单元,发现在14脚封装的集成电路块的边上安装有两个微型半可调电位器,一个在印刷电路板上标注为WR604,另一个则为WR1201。笔者根据以往维修CRT显示器的经验初步判断,这两个微型半可调电位器,很可能就是用于同步微调的,不过到底哪一个有问题呢?为了稳妥以及减少拆卸液晶显示器外壳的次数,笔者用无水酒精将两个半可调电位器全部清洗、擦拭了一遍,待酒精全部挥发以后,将液晶显示器外壳复原后通电试机,发现虽然故障有所减轻,但连续几次开机过程中故障有时还会有所反复。无奈再一次拆开液晶显示器的外壳,用一把微型十字螺丝刀将WR604顺时针调整少许,接着复原外壳并再一次通电测试,该液晶显示器显示均显示正常,至此,故障排除了。
少许调整后虽然可以使液晶显示器暂时恢复正常工作,但随着使用时间的延长,笔者认为故障很有可能还会反复。因此,笔者考虑根本的解决办法还是更换一个半可调电位器。可惜的是这种比绿豆粒大不了多少的半可调电位器在普通的电子市场上很难买到,笔者也一直没有如愿。
关键词: 电脑疑问 液晶显示器花屏故障要如何排除
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