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看电路板的口诀(电路板故障检测口诀)

来源:www.haichao.net  时间:2023-01-04 11:22   点击:263  编辑:admin   手机版

1. 电路板故障检测口诀

短路判断口诀:若电流表有示数,则短路;若电流表无示数,则断路。通过电压表电流表情判断哪个电器故障口诀:当电压表与电流表一个有示数,一个无示数则电压表测用电器故障;当电压表与电流表都无示数或都有示数,则另一个非电压表所测用电器故障

2. 电路板检查故障的六大方法

辨别电路板烧坏的方法:

1、看元件的状态:拿到一块出故障的电路板,首先观察电路板有没有明显的元件损坏,如电解电容烧毁和鼓胀、电阻烧坏以及功率器件的烧损等。

2、看电路板的焊接:如印制电路板有没有变形翘曲,有没有焊点脱落、明显虚焊,电路板覆铜皮有没有翘起、烧糊变黑。

3、观察元件的插件:如集成电路、二极管、电路板电源变压器等方向有没插错。

4、电阻电容电感的简单测试:使用万用表对量程内的电阻、电容、电感等可怀疑元件进行简单的测试,测试有否电阻阻值变大、电容短路、开路和容值变化、电感短路和开路等现象。

5、上电测试:经过上述简单观察和测试后,无法排除故障,可进行上电测试,首先测试电路板供电是否正常,如电路板的交流电源是否异常、稳压器输出是否异常、开关电源输出和波形是否异常等。

6、刷程序:对于有单片机、DSP、CPLD等可编程元件,可考虑重新刷一遍程序,排除程序运行异常造成的电路故障。

3. 判断电路故障口诀

220v空开跳闸故障快速判断口决

1、一送“砰”,火线对地线,火线对零线;

2、一送两眼冒火花,火线对火线的情况;

3、一送一滑:零对地或者地线和零线接错

4、一送过会滑是过载。

我也只知道这一种。不同得有。有不同的口诀。可以去咨询一下专业的人员口诀。

4. 电路板故障检测方法

处理电脑硬件的问题一般使用以下几种方法:;

望,及看的意思,用眼睛去看电路板上有没有烧的电路痕迹,如果是有的话可以很容易看到的。;

闻,就是用鼻子去闻电路板上的电路器件,有些电子元件是烧掉了,但是肉眼是无法看出来的,而且它上面会有一种烧焦的味道。

替换:就是拿到别的电脑上去测试,如果在别的电脑上没有问题说明这个电路板是好的。;

测:就是用万用表去对上面的电路元件进行一一检查。(这个就需要专业的人员去测了,因为第一你要会用万用表,第二你熟悉或精通电路上各个元件的性能和功能。比如:电阻的符号和欧姆的大小、电容的符号和电量的大小等等。)

5. 电路板故障检测口诀图片

具体步骤如下:

1、用24伏充电器直充

2、用12伏充电器给两个单元分别充电这是充左边单元

下面充右边单元

3、用12伏充电器,给两个单元同时充电需要先把中间的连线断开(很重要),如红色圈端子解开,最好把另一端也解开。然后按下图连接

6. 电路板维修口诀

九阳电磁炉主板上有红白黑金电阻,这是金属膜电阻,阻值22欧姆,在电路中可以起到,限流,分压等作用。

在维修电磁炉时,十之八九要检查电阻。这里分享一个快速识别色环电阻的小窍门:读色环电阻时(以四环为例)先看第三环(通常三四环的之间的间隔略大),第三环银——0.几欧,金——1至几点几欧,黑——10至几十欧,棕——100至几百欧,红——1至几K 橙——10至几十K,黄——100至几百K,绿1——至几点几M。依此类推。

五环电阻要在以上结果上扩大十倍。第四环银——1至几点几欧,金——10至几十欧,黑——100至几百欧,棕——1至几K,红——10至几十K,橙——100至几百K,黄1——至几点几M。

另外送给大家一个口诀,能快速记忆颜色代表的数字:棕一红二橙是三,四五黄绿六是蓝,紫七灰八喝白酒,见了黑色吃鸭蛋。

7. 电路故障分析口诀

1. 火灾探测器常见故障

故障现象:火灾报警控制器发出故障报警,故障指示灯亮、打印机打印探测器故障类型、时间、部位等。

故障原因:探测器与底座脱落、接触不良;报警总线与底座接触不良;报警总线开路或接地性能不良造成短路;探测器本身损坏;探测器接口板故障。

排除方法:重新拧紧探测器或增大底座与探测器卡簧的接触面积;重新压接总线,使之与底座有良好接触;查出有故障的总线位置,予以更换;更换探测器;维修或更换接口板。

2.主电源常见故障

故障现象:火灾报警控制器发出故障报警,主电源故障灯亮,打印机打印主电故障、时间。

故障原因:市电停电;电源线接触不良;主电熔断丝熔断等。

排除方法:连续供停电8h时应关机,主电正常后再开机;重新接主电源线,或使用烙铁焊接牢固;更换熔断丝或保险管。

3. 备用电源常见故障

故障现象:火灾报警控制器发出故障报警、备用电源故障灯亮,打印机打印备电故障、时间。

故障原因:备用电源损坏或电压不足;备用电池接线接触不良;熔断丝熔断等。

排除方法:开机充电24h后,备电仍报故障,更换备用蓄电池;用烙铁焊接备电的连接线,使备电与主机良好接触;更换熔断丝或保险管。

4. 通讯常见故障

故障现象:火灾报警控制器发出故障报警,通讯故障灯亮,打印机打印通讯故障、时间。

故障原因:区域报警控制器或火灾显示盘损坏或未通电、开机;通讯接口板损坏;通讯线路短路、开路或接地性能不良造成短路。

排除方法:更换设备,使设备供电正常,开警启报警控制器;检查区域报警控制器与集中报警控制器的通讯线路,若存在开路、短路、接地接触不良等故障,更换线路;检查区域报警控制器与集中报警控制器的通讯板,若存在故障,维修或更换通讯板;若因为探测器或模块等设备造成通讯故障,更换或维修相应设备。

5. 强电串入火灾自动报警及联动控制系统

产生原因:主要是弱电控制模块与被控设备的启动控制柜的接□处,如卷帘、水泵、防排烟风机、防火阀等处发生强电的串入。

排除办法:控制模块与受控设备间增设电气隔离模块。

6. 短路或接地故障而引起控制器损坏

产生原因:传输总线与大地、水管、空调管等发生电气连接,从而造成控制器接口板的损坏。

解决办法:按要求做好线路连接和绝缘处理,使设备尽量与水管、空调管隔开,保证设备和线路的绝缘电阻满足设计要求。

7. 火灾自动报警系统误报原因:产品质量;设备选择和布置不当;环境因素;其他原因(原件老化、探测器损坏)

8. 电路板故障检测口诀视频

自从液晶电视上市以来,逐渐受到了人们的喜爱,很多人家里都安装了液晶电视。和普遍的电视机相比,液晶电视比较省电、较为环保。但是对于电器来说,使用久了,出现故障也在所难免,那么该如何维修呢?

基础知识

组成结构

液晶电视机的组成原理,大体有4个主要功能模块电源板,电视主板,逻辑板,背光模块,以及屏线,遥控器,按键输入和喇叭输出。

电源板

顾名思义,电源板负责整台电视的供电。功能好比人的心脏,给人全身输送能量。如果电源板坏了,就像人的心脏停止跳动,电视机自然就不能工作了。

很多黑屏,背光不亮,指示灯不亮,遥控按键不起作用等现象都是因为电源板故障引起。

电视主板

电视主板是整个电视机控制的核心,也可以说是电视的大脑。

如果电视主板出现问题,可能导致指示灯不亮、或者指示灯颜色异常、遥控按键无响应、黑屏、花屏等现象。

逻辑板

逻辑板也称TCON板,是信号中转站。负责将主板的LVDS信号转换成屏能处理的TCON信号。

如果TCON坏了,可能导致画面黑屏,花屏,条纹干扰,屏闪,屏保等异常现象。

背光模块

背光模块的功能是给电视机显示提供背光光源。

如果电视背光不亮,很有可能是背光模块出现了问题。

LVDS信号线

屏线,又称差分信号线。如果接口松动,接触不良,很容易导致黑屏,雪花点干扰,花屏等异常现象。

注意:4K电视,因为数据量大,LVDS信号线已无法满足传输要求,一般都采用V-BY-ONE的信号线传输。

遥控接收头

遥控接收头,也称IR,负责接收遥控器的红外控制信号。如果按遥控器没有反应,可能是遥控接收头出现问题。

按键板

如果遥控器可以正常操作,但按键板不起作用,估计是按键板或者相关电路坏了。

三合一板卡

将背光模块,电源板和电视主板集合到一块板卡上,俗称三合一板卡。将背光模块,电源板和电视主板集合到一块板卡上,俗称三合一板卡。

随着产品的标准和规范化,电视模块将越来越简化。目前市面上的电视,里面的模块基本都简化成两片电路了,一块三合一主板加一片逻辑板。

工作原理

如上图,红色的箭头是供电电路,蓝色的箭头是信号电路。

电源板负责将220V交流电压转换成各个模块工作所需的直流电压;

电视主板负责处理按键信号,响应遥控器信号;

控制电源板开关,直接或间接控制背光模块;

接收各类视频信号,图像转化成LVDS信号输送给逻辑板;

声音信号输出到喇叭;

逻辑板主要功能是将电视主板输出的LVDS信号转换成液晶屏能处理的TCON信号;

背光模块负责给背光灯条供电。

维修常用工具

螺丝刀

螺丝刀是工具,分手动或电动,用于旋拧(安装)和旋松(除去)螺钉。

镊子钳

夹持导线、元件及集成电路引脚等。

万用表

,万用表又称为复用表、多用表、三用表、繁用表等,是电力电子等部门不可缺少的测量仪表,一般以测量电压、电流和电阻为主要目的。

示波器

示波器是一种用途十分广泛的电子测量仪器。它能把肉眼看不见的电信号变换成看得见的图像,便于人们研究各种电现象的变化过程。

温度可调热风枪

热风枪主要是利用发热电阻丝的枪芯吹出的热风来对元件进行焊接与摘取元件的工具。

电烙铁

电烙铁是电子制作和电器维修的必备工具,主要用途是焊接元件及导线。

锡丝

锡丝的特质是具有一定的长度与直径的锡合金丝,在电子原器件的焊接中可与电烙铁或激光配合使用。

维修技巧

基本维修的方法

直观法

肉眼观察烧黑的地方,看有无连接线松动及元器件击穿的情况。

触摸法

用手触摸关键部件,观察供电部分发热情况(数字板),特别是对老化几小时后出现的软故障情况比较实用。

问题法

了解故障出现的具体状态(比如雷击、打火、冒烟、积水及以及人为操作等)。

测量法

使用万用表、示波器测量(有些情况可用指针式万用表交流来代替示波器测量一些普通的信号)。

代换法

有条件的情况下,可以代换电源板,数字板,高频板,背光板,屏,LVDS数据线,软件等,这种方法维修快。

排除法

缩小检修范围,准确判断故障位置(如信号源部分、信号通道部分)。

逻辑检修法

该方法要求对所修板件的信号流程、电源逻辑关系非常熟悉,可以确定维修的顺序:是先从后级向前级检修,还是单一通道向公共通道检修等等。

满足法

先大体确定故障部位后,再检修部分电路的工作条件是否满足(特殊情况下可人为制造工作条件)。

对比法

条件允许的情况下,可以对比好的板件进行检修,也可以对比同一板件上相同的电路(对称电路)来进行检修。

先软件后硬件

软件涉及的故障范围广,但是需要检修的范围小,对于一些软故障,建议先升级软件。

初步检修流程

维修口诀

液晶维修并不难,工作原理记心间;

电压来自电源板,亮度来自背光源;

信号处理机芯板,显示分配控制板;

5V供电最勤劳,一年四季歇不了;

12V供给机芯板,中放功放向它看;

24V送到背光板,无它屏幕缺光源;

机芯板子是领导,开关信号向它要;

电源模块背光板,电平高开(机)低关;

PWM脉冲很重要,少了亮度提不高;

LVDS线要求高,变质松动有干扰;

液晶电视不普通,程序经常闹罢工;

三天两天发神经,需要复位来摆平;

液晶屏幕很脆弱,要维修时细(心)操作

平板维修费用高,学好技术很辛劳;

赚钱固然很重要,安全二字记心牢。

常见故障分析

显示器整机无电

1、电源故障

这是一个应该说是非常简单的故障,一般的液晶显示器分机内电源和机外电源两种,机外的常见一些。不论那种电源,易损的一般是一些小元件,象保险管、整流桥、300V滤波电容、电源开关管、电源管理IC、整流输出二极管、滤波电容等。这些常用的芯片在专业液晶配件店里都能买到。

2、驱动板故障

驱动板烧保险或者是稳压芯片出现故障,有部分机器是把开关电源内置,输出两组电源,其中一组是5V,供信号处理用,另外一组是12V提供高压板点背光用,如果开关电源部分电路出现了故障会有可能导致两组电源均没输出先查12V电压正常否,跟着查5V电压正常否,因为A/D驱动板的MCU芯片的工作电压是5V,所以查找开不了机的故障时,先用万用表测量5V电压,如果没有5V电压或者5V电压变得很低,那么一种可能是电源电路输入级出现了问题,也就是说12V转换到5V的电源部分出了问题,这种故障很常见检查5端稳压块(常见型号8050SD-LM2596-AIC15-01等)。

另一种可能就是5V的负载加重了,把5V电压拉得很低,换一种说法就是说,后级的信号处理电路出了问题,有部分电路损坏,引起负载加重,把5V电压拉得很低,逐一排查后级出现问题的元件,替换掉出现故障的元件后,5V能恢复正常,故障一般就此解决,也经常遇到5V电压恢复正常后还不能正常开机的,这种情况也有多种原因,一方面是MCU的程序被冲掉可能会导致不开机。还有就是MCU本身损坏,比如说MCU的I/O口损坏,使MCU扫描不了按键,遇到这种由MCU引起的故障,找硬件的问题是没有用的,就算你换了MCU也解决不了问题,因为MCU是需要编程和写码的,在没办法找到原厂的AD驱动板替换的情况下,我们只能用通用A/D驱动板代换如151D或161B等。

显示屏黑屏,无背光,电源灯绿灯常亮

斜视液晶屏有显示图像,是因为MCU问题造成没有输出开关控制电压,可以直接提取3端稳压块的。

(AIC1084)3.3V代替,修理高压板的思路(电源保险丝--开关控制管--电源管理IC--推挽发大管--电源开关管--DA转换电路(储能电感整流管)--LC升压电路(升压变压器、升压电容)--耦合电容--灯管。

屏幕亮线,亮带或者是暗线

这种问题,一般是液晶屏的故障。

亮线故障一般是连接液晶屏本体的排线出了问题或者某行和列的驱动IC损坏

暗线一般是屏的本体有漏电,或者TAB柔性板连线开路以上两种问题基本上就是给机器判了死刑了,没有维修价值的,因为一块屏的价格太高了。(广州有专门更换码片的,收费极高,返修率也高)。

花屏或者是白屏

这种问题一般是屏的驱动电压出了问题,先换驱动板和驱屏线试验,若不行检查屏背板供电电路。

维修思路:驱动板5V转3.3V的稳压块(AIC1084)是否有供电输出--屏体驱动板保险丝(F)-3.3V--DC转换电路--负压形成IC(-7V)--行列驱动IC。

AAT1101AM150XN05屏电源管理芯片,损坏后表现为白屏开机图像暗淡等。

AAT1164M170EG01新款屏通病,主要用在明基FP71G+液晶显示器上面。用一段时间会白屏、关机在开用一段时间又出现白屏。本芯片为液晶屏高压产生及管理芯片、明基液晶显示器常坏、故障为:白屏。

偏色故障

一般可以进入工厂调整模式进行调整。

维修思路:更换屏线和转接板--重写驱动程序--驱动板坏(不常见)--屏背板的控制IC坏(不常见)--拔掉屏线观察背光颜色(背光偏色为灯管老化)--换灯管。

字符虚或拖尾

维修思路:检查VGA信号线,重点看RGB三色线的地线是否连接正常--更换屏线或转接板--重写驱动程序--换驱动板--LCD屏背板信号接口 IC坏--LCD屏背板对比度电位器调整--LCD屏导光板错位--偏光片错位。

LCD屏幕内部有污点

维修思路:擦拭或更换换保护膜--拆开屏体清洗外层偏光片和有机玻璃(用棉球纯净水处理)--风筒吹干。

LCD屏漏光或光线不均

维修思路:重新安装灯管--调整导光板。

LCD屏亮点

一个或二个大的亮点,可以尝试轻轻用指尖压亮点,可消失,说明多为此像素的开关管和电极虚连小的黑点和灰点有可能是内部导光板或偏光片有灰尘造成可清洗处理。

LCD屏亮度低

检查高压板ADJ亮度调节电路--换灯管--换高压板---调整或更换导光板。

错误提示超出频率范围

检查信号线--重写MCU驱动程序--更换EPROM--重写EPROM程序--换驱动板。

通电后不按开关按键即白屏,出现背光按键后图像可正常显示

高压板接口的开关信号和ADJ信号反接造成部分属于驱动板MCU的开关信号输出不正常,可以重写MCU程序修复--换MCU。

补充一点,对于灯管老化的屏更换时要搞清灯管的尺寸,因为尽管屏幕尺寸一样,但是灯管长度与粗细略有差异,在找不到相同尺寸灯管的时候,如果能用短灯则好,如果不能使用,稍长的的灯管用手术刀小心切除屏框,并用热缩管做好绝缘。

注意事项

电视机是有电高压的一种电器,维修时有关的安全问题一定要注意。

1、打开机壳:要注意不能用蛮力打开机壳,如果太紧打不开,一定是还有螺钉或卡扣没有松开,要再仔细找找;拉开机壳时有的电视机电路板与机壳之间会有电线相连,要注意不要拉坏,比较好先折下机壳上固定的电路板;拉开机壳时要拿稳机壳,不要脱手掉下,否则容易砸到显像管管径,一旦砸断可就麻烦了。

2、要注意电视机的“热地”:有的电视机的电路板的地是“热地”,就是与市电没有隔离,如果恰巧电视机的电源插头又将未隔离的电视机的“地”端插到市电的“火”线上,那么维修时如果你不小心碰到电视机的某个接“地”的部分,就有触电的危险。一方面触电本身很危险,另一方面人在触电时身体会发生不由自主的痉挛,一旦把电视机拉到地上,就又出大麻烦了。解决这个问题比较好是用隔离变压器,如果没有,比较好在电视机通电时能调整好插头方向,使电视机的“地”接到市电的“零”线上,这样可以使电视机比较容易碰到的地方不“电”人,但是电视机里还是有与“火”线相连的强电的,仍然要小心。

3、要注意电视机内的高压:在更换行输出变压器的时候,一定要用万用表笔或其它导线将显像管高压帽下的高压泄放干净,否则在摘下高压连线时会受到高压电击,同样比较危险。

如何保养

1、保持干燥

放置的中央,环境要保持干燥并远离化学药品。假如放置环境湿度很大,电器内部就会结露,容易形成漏电、短路等。平常使用的发胶、灭蚊剂等都是高挥发性化学品,也会对液晶显现屏形成损伤。

2、亮度调低

日常使用,尽量防止长时间显现同一张画面。长时间工作容易惹起内部老化或烧坏,特别糟糕的是长时间内显现同一画面,可能会招致某些像素过热,形成内部产生坏点。而这种损坏不能修复。因而不用时应该关闭显现屏或选择屏幕保护程序,或者把显现屏亮度调低点。

3、不能频繁清洗

液晶显现屏不能频繁清洗。正确的清洁办法是拿一块沾有少许玻璃清洁剂的屏幕擦布,轻力把污迹擦去。注意不要让清洁剂流到屏幕、屏框接口中,以免出现短路。也不要用硬质毛巾擦洗,以免刮花屏幕。还要定时定量擦洗。

4、制止坏习气

杜绝使用坏习气。不要用手对屏幕指指点点。此外变压器电压很高,不要在带电的状况下翻开屏的后盖。

%3Chowto_content%3E[{"type":"paragraph","attrs":{"is_abstract":true},"children":[{"type":"text","text":"自从液晶电视上市以来,逐渐受到了人们的喜爱,很多人家里都安装了液晶电视。和普遍的电视机相比,液晶电视比较省电、较为环保。但是对于电器来说,使用久了,出现故障也在所难免,那么该如何维修呢?","id":""}],"text":"","id":"WW8Ide2aGoiCgsxk5encV6gvnkh"},{"type":"heading","attrs":{"level":1},"children":[{"type":"text","text":"基础知识","id":""}],"text":"","id":"Zg4sdAmW0oa0Gsx50oLcYGQdnbR"},{"type":"heading","attrs":{"level":2},"children":[{"type":"text","text":"组成结构","id":""}],"text":"","id":"Q2qyduGcyoGOuAxkbcycCbuBnlg"},{"type":"paragraph","children":[{"type":"text","text":"液晶电视机的组成原理,大体有4个主要功能模块电源板,电视主板,逻辑板,背光模块,以及屏线,遥控器,按键输入和喇叭输出。","id":""}],"text":"","id":"YqSOdSGksoKCkkxgjdpc8VC0nEd"},{"type":"image","attrs":{"height":547,"note":[{"type":"text","text":"组成结构","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/d49597eb3f2f458fb1aacdb8bcdbef9c","width":600},"text":"","id":"KIuGduc4Yo64sGxgDHGcyS0Hnog"},{"type":"heading","attrs":{"level":2},"children":[{"type":"text","text":"电源板","id":""}],"text":"","id":"NCcadCGASoIKKaxI1gYcygzZnoc"},{"type":"image","attrs":{"height":382,"note":[{"type":"text","text":"电源板","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/33c208a51667444093165fd7f535bdad","width":640},"text":"","id":"N8OodMuAWo6Y0kxgTEac2Ntdnic"},{"type":"paragraph","children":[{"type":"text","text":"顾名思义,电源板负责整台电视的供电。功能好比人的心脏,给人全身输送能量。如果电源板坏了,就像人的心脏停止跳动,电视机自然就不能工作了。","id":""}],"text":"","id":"E2y2dAoKqo22aoxkhhmcxKcinxb"},{"type":"paragraph","children":[{"type":"text","text":"很多黑屏,背光不亮,指示灯不亮,遥控按键不起作用等现象都是因为电源板故障引起。","id":""}],"text":"","id":"K6S2dK66Uos0mCx6PqTc7rRPnIe"},{"type":"heading","attrs":{"level":3},"children":[{"type":"text","text":"电视主板","id":""}],"text":"","id":"Om6gd4siSo44U6xyplZcfDDQnzX"},{"type":"paragraph","children":[{"type":"text","text":"电视主板是整个电视机控制的核心,也可以说是电视的大脑。","id":""}],"text":"","id":"HQWQd2WKgoEWIExa0EecUNIln8f"},{"type":"paragraph","children":[{"type":"text","text":"如果电视主板出现问题,可能导致指示灯不亮、或者指示灯颜色异常、遥控按键无响应、黑屏、花屏等现象。","id":""}],"text":"","id":"OyS4dCMsKoCkwSx8w6qcWrSFnCc"},{"type":"heading","attrs":{"level":3},"children":[{"type":"text","text":"逻辑板","id":""}],"text":"","id":"BAA0dYS4ko8GaExOAlwcSMQzn3f"},{"type":"image","attrs":{"height":200,"note":[{"type":"text","text":"逻辑板","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/6a2ec3b6487a474bb0572cd6b41a6a41","width":476},"text":"","id":"ZgksdK60koWCCuxANPMcX2Ijnuf"},{"type":"paragraph","children":[{"type":"text","text":"","id":""}],"text":"","id":"GKWadUmOWoQK6cxQbUoclY8cn9f"},{"type":"paragraph","children":[{"type":"text","text":"逻辑板也称TCON板,是信号中转站。负责将主板的LVDS信号转换成屏能处理的TCON信号。","id":""}],"text":"","id":"AQKCd4EUoooEGwxwV6EcWW8EnVg"},{"type":"paragraph","children":[{"type":"text","text":"如果TCON坏了,可能导致画面黑屏,花屏,条纹干扰,屏闪,屏保等异常现象。","id":""}],"text":"","id":"Nwyud4k2moy8w0xMfDUcsxd2nYf"},{"type":"heading","attrs":{"level":3},"children":[{"type":"text","text":"背光模块","id":""}],"text":"","id":"W0iudm0eMosGogxEnR0cFf7unhh"},{"type":"image","attrs":{"height":376,"note":[{"type":"text","text":"背光模块","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/f0a58b74bfb149388085b7d3c065f517","width":640},"text":"","id":"DkCCdyq0eoGMsWxGg10cl1h3nue"},{"type":"paragraph","children":[{"type":"text","text":"背光模块的功能是给电视机显示提供背光光源。","id":""}],"text":"","id":"XgqgdA6eSoamscxGkTEcrEuhn7e"},{"type":"paragraph","children":[{"type":"text","text":"如果电视背光不亮,很有可能是背光模块出现了问题。","id":""}],"text":"","id":"FEMsdQsKaoEuyGxMx62cer6vn8d"},{"type":"heading","attrs":{"level":3},"children":[{"type":"text","text":"LVDS信号线","id":""}],"text":"","id":"KesmdsScsoMkAaxUZkacXFfanwf"},{"type":"image","attrs":{"height":174,"note":[{"type":"text","text":"LVDS信号线","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/f2f5112c462f4d7689d15cca1b1d7274","width":288},"text":"","id":"IG2edW4gAoimeMx1qfDc7n8EnbS"},{"type":"paragraph","children":[{"type":"text","text":"","id":""}],"text":"","id":"QM0odQQqaoIgYkxmu1Nc6e2hn7g"},{"type":"paragraph","children":[{"type":"text","text":"屏线,又称差分信号线。如果接口松动,接触不良,很容易导致黑屏,雪花点干扰,花屏等异常现象。","id":""}],"text":"","id":"EcUMdCeuMoMgs8x2v7Nc6yronId"},{"type":"paragraph","children":[{"type":"text","text":"注意:4K电视,因为数据量大,LVDS信号线已无法满足传输要求,一般都采用V-BY-ONE的信号线传输。","id":""}],"text":"","id":"HwyGdSIWkoKoiUx06WXcQbkUnOc"},{"type":"heading","attrs":{"level":3},"children":[{"type":"text","text":"遥控接收头","id":""}],"text":"","id":"D8OCduQagoGUkmxCK1hc1UlanHg"},{"type":"image","attrs":{"height":386,"note":[{"type":"text","text":"遥控接收头","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/81b73b4097b34fa7bd7d91fc61b8ffbe","width":640},"text":"","id":"K2iYdKsC6oggeMxOInhcnIq1nCe"},{"type":"paragraph","children":[{"type":"text","text":"遥控接收头,也称IR,负责接收遥控器的红外控制信号。如果按遥控器没有反应,可能是遥控接收头出现问题。","id":""}],"text":"","id":"EUckd0E8woqg2ixQZxYcNcumn3f"},{"type":"heading","attrs":{"level":3},"children":[{"type":"text","text":"按键板","id":""}],"text":"","id":"CeAEdImqSoAkwIxYFN6c7Mrpnfh"},{"type":"image"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被冲掉可能会导致不开机。还有就是MCU本身损坏,比如说MCU的I/O口损坏,使MCU扫描不了按键,遇到这种由MCU引起的故障,找硬件的问题是没有用的,就算你换了MCU也解决不了问题,因为MCU是需要编程和写码的,在没办法找到原厂的AD驱动板替换的情况下,我们只能用通用A/D驱动板代换如151D或161B等。","id":""}],"text":"","id":"WEKKdMm82oO0AOxmijgcGJ82nCg"},{"type":"image","attrs":{"height":718,"note":[{"type":"text","text":"显示器整机无电","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/6877eef394f0460391549cc7950ff2b9","width":1077},"text":"","id":"TemOdY8o8ooCscxC4v0cctYNnJe"},{"type":"heading","attrs":{"level":2},"children":[{"type":"text","text":"显示屏黑屏,无背光,电源灯绿灯常亮","id":""}],"text":"","id":"ScwmdYC2soiC0Uxy0AScaYgon7c"},{"type":"paragraph","children":[{"type":"text","text":"斜视液晶屏有显示图像,是因为MCU问题造成没有输出开关控制电压,可以直接提取3端稳压块的。","id":""}],"text":"","id":"DcCAd0sWyoUm0WxzWWcclrOVnIg"},{"type":"paragraph","children":[{"type":"text","text":"(AIC1084)3.3V代替,修理高压板的思路(电源保险丝--开关控制管--电源管理IC--推挽发大管--电源开关管--DA转换电路(储能电感整流管)--LC升压电路(升压变压器、升压电容)--耦合电容--灯管。","id":""}],"text":"","id":"GUWGd8kEoo68ewx80Iqc5gxsntc"},{"type":"image","attrs":{"height":683,"note":[{"type":"text","text":"显示屏黑屏,无背光,电源灯绿灯常亮","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/28d1d08e0d744012a98d93b2b825562d","width":1024},"text":"","id":"MsYyd8kKIoYUAsxWIPDcYNDFnKb"},{"type":"heading","attrs":{"level":2},"children":[{"type":"text","text":"屏幕亮线,亮带或者是暗线","id":""}],"text":"","id":"EOYgdaWOwoggwoxohgqc5uwvn5b"},{"type":"paragraph","children":[{"type":"text","text":"这种问题,一般是液晶屏的故障。","id":""}],"text":"","id":"J04udMScEogEgixag7UcHcR4nyh"},{"type":"paragraph","children":[{"type":"text","text":"亮线故障一般是连接液晶屏本体的排线出了问题或者某行和列的驱动IC损坏","id":""}],"text":"","id":"AcEAdaQkIoUY4OxY585cDxs6n4d"},{"type":"paragraph","children":[{"type":"text","text":"暗线一般是屏的本体有漏电,或者TAB柔性板连线开路以上两种问题基本上就是给机器判了死刑了,没有维修价值的,因为一块屏的价格太高了。(广州有专门更换码片的,收费极高,返修率也高)。","id":""}],"text":"","id":"HWy8dsS2IoyCmqx2xcmc66POnFg"},{"type":"image","attrs":{"height":2000,"note":[{"type":"text","text":"屏幕亮线,亮带或者是暗线","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/f8d9eb1e799a4641b7f7ba71179f73c8","width":3000},"text":"","id":"KY0Ad8EKooqioaxkZVwcJ31Unxf"},{"type":"heading","attrs":{"level":2},"children":[{"type":"text","text":"花屏或者是白屏","id":""}],"text":"","id":"OA26d4yEeomOIAxOyyFc1I1anxg"},{"type":"paragraph","children":[{"type":"text","text":"这种问题一般是屏的驱动电压出了问题,先换驱动板和驱屏线试验,若不行检查屏背板供电电路。","id":""}],"text":"","id":"JQiIdcoY0oyyKExqonxcIxPVnie"},{"type":"paragraph","children":[{"type":"text","text":"维修思路:驱动板5V转3.3V的稳压块(AIC1084)是否有供电输出--屏体驱动板保险丝(F)-3.3V--DC转换电路--负压形成IC(-7V)--行列驱动IC。","id":""}],"text":"","id":"BwSgdaAkgoEwGuxQt1GcFIwRnde"},{"type":"paragraph","children":[{"type":"text","text":"AAT1101AM150XN05屏电源管理芯片,损坏后表现为白屏开机图像暗淡等。","id":""}],"text":"","id":"W8YwdySA4ogUMCxWAF3chxuOnBd"},{"type":"paragraph","children":[{"type":"text","text":"AAT1164M170EG01新款屏通病,主要用在明基FP71G+液晶显示器上面。用一段时间会白屏、关机在开用一段时间又出现白屏。本芯片为液晶屏高压产生及管理芯片、明基液晶显示器常坏、故障为:白屏。","id":""}],"text":"","id":"F6UcdsIaYoigw4xhXQYcSTbtnA4"},{"type":"image","attrs":{"height":720,"note":[{"type":"text","text":"花屏或者是白屏","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/0382d695e62249e48ce88ddd45e7eab2","width":1080},"text":"","id":"PECGdywYoouQEqxcjYVcjWO4nsg"},{"type":"heading","attrs":{"level":2},"children":[{"type":"text","text":"偏色故障","id":""}],"text":"","id":"WUakdWow4oC0AYx8TxNcdEFKn2c"},{"type":"paragraph","children":[{"type":"text","text":"一般可以进入工厂调整模式进行调整。","id":""}],"text":"","id":"KAwwd8GmcoMgQoxJOl6cUuWingX"},{"type":"paragraph","children":[{"type":"text","text":"维修思路:更换屏线和转接板--重写驱动程序--驱动板坏(不常见)--屏背板的控制IC坏(不常见)--拔掉屏线观察背光颜色(","id":""},{"type":"text","text":"背光偏色","id":""},{"type":"text","text":"为灯管老化)--换灯管。","id":""}],"text":"","id":"OE2EdwMqAo22G0x2hsKcJpSYnYf"},{"type":"image","attrs":{"height":595,"note":[{"type":"text","text":"偏色故障","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/682812f3a52745ab9015c2bdb8a8ffca","width":892},"text":"","id":"R2aAd6qASoCwSqx2DfncS7VlnFb"},{"type":"heading","attrs":{"level":2},"children":[{"type":"text","text":"字符虚或拖尾","id":""}],"text":"","id":"QS0Ydw8IkomMO0xQDMicNxRVnid"},{"type":"paragraph","children":[{"type":"text","text":"维修思路:检查VGA信号线,重点看RGB三色线的地线是否连接正常--更换屏线或转接板--重写驱动程序--换驱动板--LCD屏背板信号接口 IC坏--LCD屏背板对比度电位器调整--LCD屏导光板错位--偏光片错位。","id":""}],"text":"","id":"D0KUdse84ouMuQxGGovcCqUWnHf"},{"type":"image","attrs":{"height":683,"note":[{"type":"text","text":"字符虚或拖尾","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/49e51c98340e47e8b7bfb8076eb3684a","width":1024},"text":"","id":"Dyu2dmkEsoSiimxyOIScRdQ8nHh"},{"type":"heading","attrs":{"level":2},"children":[{"type":"text","text":"LCD屏幕内部有污点","id":""}],"text":"","id":"WIyKdkuCuoI2MqxSkyZcRKEcnMg"},{"type":"paragraph","children":[{"type":"text","text":"维修思路:擦拭或更换换保护膜--拆开屏体清洗外层偏光片和有机玻璃(用棉球纯净水处理)--风筒吹干。","id":""}],"text":"","id":"Ygi2dkiY4oO6sExAXsycPzo6nSc"},{"type":"image","attrs":{"height":746,"note":[{"type":"text","text":"LCD屏幕内部有污点","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/3411022d6b21474aa77b1f139bcb0fcf","width":1119},"text":"","id":"EAUGdQi4yoaaY4xEFqIcBxQrnKd"},{"type":"heading","attrs":{"level":2},"children":[{"type":"text","text":"LCD屏漏光或光线不均","id":""}],"text":"","id":"O4KWdaCcio8gqGxuGtWcl6ktnVc"},{"type":"paragraph","children":[{"type":"text","text":"维修思路:重新安装灯管--调整导光板。","id":""}],"text":"","id":"EgYMdOAgOosEU8xu8BJclmLjnqg"},{"type":"image","attrs":{"height":575,"note":[{"type":"text","text":"LCD屏漏光或光线不均","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/4f1fae90dd7f4885875a98b12d344c37","width":862},"text":"","id":"KaA2dmCEQocMuwxaEhlcgUhwnKd"},{"type":"heading","attrs":{"level":2},"children":[{"type":"text","text":"LCD屏亮点","id":""}],"text":"","id":"RQE0dwIycoAK2ax2hmVc4DIWn2c"},{"type":"paragraph","children":[{"type":"text","text":"一个或二个大的亮点,可以尝试轻轻用指尖压亮点,可消失,说明多为此像素的开关管和电极虚连小的黑点和灰点有可能是内部导光板或偏光片有灰尘造成可清洗处理。","id":""}],"text":"","id":"BCQUdoykSoGQcAxh5gQcr7XenxI"},{"type":"image","attrs":{"height":720,"note":[{"type":"text","text":"LCD屏亮点","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/39e02217bd5d47d88ba8642545866e1b","width":1080},"text":"","id":"CEgKd8sgWosqEmxG8gBcswkynme"},{"type":"heading","attrs":{"level":2},"children":[{"type":"text","text":"LCD屏亮度低","id":""}],"text":"","id":"GOQmdYWuioG6KExmKzJcaD6anVh"},{"type":"paragraph","children":[{"type":"text","text":"检查高压板ADJ亮度调节电路--换灯管--换高压板---调整或更换导光板。","id":""}],"text":"","id":"PIgCdkW6eoKeEAxA1K6cYRjknzh"},{"type":"image","attrs":{"height":720,"note":[{"type":"text","text":"LCD屏亮度低","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/d2f309cae5554291ad52f0a37e78fa36","width":1080},"text":"","id":"PMYMdWGmqoKiQMxUzJ5cZG7bnBf"},{"type":"heading","attrs":{"level":2},"children":[{"type":"text","text":"错误提示超出频率范围","id":""}],"text":"","id":"UKkGdaY0UoYoeKx0AVLcATRRnTb"},{"type":"paragraph","children":[{"type":"text","text":"检查信号线--重写MCU驱动程序--更换EPROM--重写EPROM程序--换驱动板。","id":""}],"text":"","id":"MAEMd8Mywom02Ox6f52cPjNondb"},{"type":"image","attrs":{"height":683,"note":[{"type":"text","text":"错误提示超出频率范围","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/ddcfcfe2eef44b059d28fdf4aff6f628","width":1024},"text":"","id":"QoYidAMsMo2gk4xye2Bchj7nn0f"},{"type":"heading","attrs":{"level":2},"children":[{"type":"text","text":"通电后不按开关按键即白屏,出现背光按键后图像可正常显示","id":""}],"text":"","id":"OqYsdU2e6oCMuuxGCkRcnqnpnne"},{"type":"paragraph","children":[{"type":"text","text":"高压板接口的开关信号和ADJ信号反接造成部分属于驱动板MCU的开关信号输出不正常,可以重写MCU程序修复--换MCU。","id":""}],"text":"","id":"UOw0dACO4oKkYIxeQAFcx3sfnVf"},{"type":"paragraph","children":[{"type":"text","text":"补充一点,对于灯管老化的屏更换时要搞清灯管的尺寸,因为尽管屏幕尺寸一样,但是灯管长度与粗细略有差异,在找不到相同尺寸灯管的时候,如果能用短灯则好,如果不能使用,稍长的的灯管用手术刀小心切除屏框,并用热缩管做好绝缘。","id":""}],"text":"","id":"UyU8dEUCaoUWygxc98xcWNPknee"},{"type":"image","attrs":{"height":483,"note":[{"type":"text","text":"通电后不按开关按键即白屏,出现背光按键后图像可正常显示","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/e69eef55771b48e7bbf6ebcdc5b0165c","width":725},"text":"","id":"FkEQdQikyouEcMx2xS3chyPon8d"},{"type":"heading","attrs":{"level":1},"children":[{"type":"text","text":"注意事项","id":""}],"text":"","id":"GAsmd4agGouIk2x43LCc4WoTnRg"},{"type":"paragraph","children":[{"type":"text","text":"电视机是有电高压的一种电器,维修时有关的安全问题一定要注意。","id":""}],"text":"","id":"YCaIdiMsSogi28xUdokcdns6nng"},{"type":"paragraph","children":[{"type":"text","text":"1、打开机壳:要注意不能用蛮力打开机壳,如果太紧打不开,一定是还有螺钉或卡扣没有松开,要再仔细找找;拉开机壳时有的电视机电路板与机壳之间会有电线相连,要注意不要拉坏,比较好先折下机壳上固定的电路板;拉开机壳时要拿稳机壳,不要脱手掉下,否则容易砸到显像管管径,一旦砸断可就麻烦了。","id":""}],"text":"","id":"RG2KdeSkco0eAKxIN1TcdXBFneg"},{"type":"image","attrs":{"height":888,"note":[{"type":"text","text":"注意事项","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/3541dbd8ad7a44cab04154722ed2ea1b","width":1332},"text":"","id":"HcUGdoY4GoEOYxxSOaVcjAjbnio"},{"type":"paragraph","children":[{"type":"text","text":"2、要注意电视机的“热地”:有的电视机的电路板的地是“热地”,就是与市电没有隔离,如果恰巧电视机的电源插头又将未隔离的电视机的“地”端插到市电的“火”线上,那么维修时如果你不小心碰到电视机的某个接“地”的部分,就有触电的危险。一方面触电本身很危险,另一方面人在触电时身体会发生不由自主的痉挛,一旦把电视机拉到地上,就又出大麻烦了。解决这个问题比较好是用隔离变压器,如果没有,比较好在电视机通电时能调整好插头方向,使电视机的“地”接到市电的“零”线上,这样可以使电视机比较容易碰到的地方不“电”人,但是电视机里还是有与“火”线相连的强电的,仍然要小心。","id":""}],"text":"","id":"YEMOdOAAwomg86xkPm3cBlyqnEe"},{"type":"image","attrs":{"height":682,"note":[{"type":"text","text":"注意事项","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/e970d754d0ab4531b80dbfe870179d92","width":1024},"text":"","id":"SeQOdeAgUoYeucxXA1NcWhdHniE"},{"type":"paragraph","children":[{"type":"text","text":"3、要注意电视机内的高压:在更换行输出变压器的时候,一定要用万用表笔或其它导线将显像管高压帽下的高压泄放干净,否则在摘下高压连线时会受到高压电击,同样比较危险。","id":""}],"text":"","id":"TE2WdG8MgoUkOUxUDBNcZVgnnLV"},{"type":"image","attrs":{"height":683,"note":[{"type":"text","text":"注意事项","id":""}],"url":"https://p3.douyinpic.com/large/tos-cn-i-qvj2lq49k0/3d725834cf604f28a031e3d43eccc47f","width":1024},"text":"","id":"KeMGdIuYioCEyGxWMP9c3GeTnqh"},{"type":"heading","attrs":{"level":1},"children":[{"type":"text","text":"如何保养","id":""}],"text":"","id":"Z6QEdMcCuoamSqxUh4rcvQvEnSe"},{"type":"paragraph","children":[{"type":"text","text":"1、保持干燥","id":""}],"text":"","id":"Uq6qdkaMyoi0AgxobSVcuh03nhc"},{"type":"paragraph","children":[{"type":"text","text":"放置的中央,环境要保持干燥并远离化学药品。假如放置环境湿度很大,电器内部就会结露,容易形成漏电、短路等。平常使用的发胶、灭蚊剂等都是高挥发性化学品,也会对液晶显现屏形成损伤。","id":""}],"text":"","id":"SQkMdwWcSoSIqmxCen9cYGrQnTg"},{"type":"paragraph","children":[{"type":"text","text":"2、亮度调低","id":""}],"text":"","id":"GmA2dmAcQoIgS6xcTwycWgUXn8g"},{"type":"paragraph","children":[{"type":"text","text":"日常使用,尽量防止长时间显现同一张画面。长时间工作容易惹起内部老化或烧坏,特别糟糕的是长时间内显现同一画面,可能会招致某些像素过热,形成内部产生坏点。而这种损坏不能修复。因而不用时应该关闭显现屏或选择屏幕保护程序,或者把显现屏亮度调低点。","id":""}],"text":"","id":"SeyYdg6moo2qSwxAdYKchuc0nRb"},{"type":"paragraph","children":[{"type":"text","text":"3、不能频繁清洗","id":""}],"text":"","id":"N848dWgAmomgIOxk7BLcs9wcnsd"},{"type":"paragraph","children":[{"type":"text","text":"液晶显现屏不能频繁清洗。正确的清洁办法是拿一块沾有少许玻璃清洁剂的屏幕擦布,轻力把污迹擦去。注意不要让清洁剂流到屏幕、屏框接口中,以免出现短路。也不要用硬质毛巾擦洗,以免刮花屏幕。还要定时定量擦洗。","id":""}],"text":"","id":"HcMadkiiooWOkcxKaNackUibnKe"},{"type":"paragraph","children":[{"type":"text","text":"4、制止坏习气","id":""}],"text":"","id":"UquIdAgkYoM22axczmCckeQ6nzg"},{"type":"paragraph","children":[{"type":"text","text":"杜绝使用坏习气。不要用手对屏幕指指点点。此外变压器电压很高,不要在带电的状况下翻开屏的后盖。","id":""}],"text":"","id":"IEuGdMIkUo68QoxmAQdcM5DWnbc"},{"type":"paragraph","children":[{"type":"text","text":"","id":""}],"text":"","id":"I8mydKKoWoei8exM3hYcwT4BnJc"}]%3C%2Fhowto_content%3E

9. 电路板故障判断口诀

线路板的口诀如下:

1、输入与输出分开走

当输入是一个小信号,而输出是一个被放大了的比较强的功率信号,布板时应避免输入信号与输出信号走的太近,万不得已时,小信号与功率信号也不能平行走线

2、信号与电源分开走

在系统工作的时候,电源的成分并不纯净,为防止引起干扰,信号线应避免与电源的正极平行走线,尤其是以开关电源供电的高频电路

3、,高频与低频分开走

这个不用解释,高频信号辐射也能引起低频部分的稳定和噪声

4、预留足够的线径与安全间距

现在的PCB制造技术越来越精密了,但我们也不能走极限,虽然现在很多厂家的线径都能做到0.15mm,间距0.15mm,在实际的产品设计时,如果电路不是需要特别小,我们还是至少大于0.2mm为妥当,这样可以提高PCB制作的可靠性,免得出现PCB短路和断路的现象

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