SERVICE
MANUAL
- 1 -
安全说明
在检修与调校本机之前,请先阅读以下“PDP 维修注意事项”，“屏坏点判别及标
准”.
1、PDP 维修注意事项
为了避免可能出现的危险、损伤或者身体伤害，避免PDP 屏出现新的损坏，维修人员务
必请仔细阅读如下条款，如果你忽略了以下警告，将会导致致命的伤害：
1． 不同型号的屏存在差异，不可直接代换，务必原型号更换。
2． PDP 模块（包括屏、驱动电路、逻辑电路和电源模块）工作电压大约为350V。如
果要在正常工作时或者刚刚断电时对PDP 模块进行操作，你必须采取合适的措施
避免电击，并且不要直接触摸工作模块的电路或者金属部分。这是因为驱动部分
的电容,即使断电以后仍然短时保持较高的电压，所以断电以后，一定要确保至少
一分钟以后方可进行相关操作。
3． 不要给该模块提供高于规格书上要求的任何电源。如果你使用的电源偏离了规格
书上的数值，可能导致着火或者损坏该模块。
4． 不要在不良环境下进行操作或安装，例如近水区域----浴室、洗衣房、厨房水槽，
靠近火源、发热器件，或者直接暴露在阳光之下等类似环境。否则将会产生不良
的后果。
5． 如果一些异物（如水、液体、金属片或其他杂物）不慎掉进该模块中时，必须马
上断电;并且不要挪动模块上的任何东西，因为可能导致碰到高压或者短路从而导
致火灾或电击。
6． 如果该模块出现冒烟、异味或异常声响，请马上断电。同样，如果上电以后或者
操作过程中发现屏不工作，也必须马上断电，并且不要再同样条件下继续操作。
7． 不要在该模块工作或刚刚断电时，拔插模块上的连接线。这是因为驱动电路上的
电容仍然保持较高的电压，如要拔插连接线，敬请在断电后至少等待一分钟。
8． 由于该模块是玻璃面板，请避免外力挤压，因为玻璃破损可能伤人。移动该模块
时需二人配合，以免发生意外。
9． 整机在设计时，已充分考虑对流散热，顶部的圆孔是用来散热的，为了防止过热，
在正常的工作时候，不要在其上面加上遮盖物，同时不要将其放置在狭小和通风
不良的地方。
10． PDP 电路中有很多是CMOS 集成电路组成，所以要注意防止静电。因此维修时，一
定要罩上防静电袋，操作之前，一定要保证充分接地。
注意:此维修手册仅供维修人员参考使用.在维修机器前,请先参阅下列注意事项.
- 2 -
11． 屏的四周分布了很多连接线，维修或搬动时请注意不要碰到或划伤，这些连接线
一旦损坏将导致屏无法工作，且无法维修；
12． 屏部分电路板的连接器都比较精细，更换时务必小心，以免损坏；
13． 运输和搬运时要特别小心，剧烈的震动可能导致玻璃屏破裂或者驱动电路受损，
因此运输和搬运时一定要用坚固的外壳包装。
14． 储存时要放在一个环境可控的地方，避免温度和湿度超过说明书规定的范围。如
果要长时间放置，则应罩上防潮袋集中统一堆放。其使用环境要求如下表所示：
温度 使用范围 0～50 度
储存范围 －15～60 度
湿度 使用范围 20％～80％
储存范围 20％～80％
15． 如果长时间显示某一固定画面，可能导致固定画面的亮度和色度与活动画面出现
差异，这是由于前者荧光粉的密度降低的缘故，并非故障。另一方面，即使画面
发生了变化，其亮度仍然会保持一段时间（几分钟）。这是等离子本身固有的特点，
不是异常。但在使用时，请尽量避免长时间显示高亮的静止图像。
16． 作为数字处理显示设备，模块具有错误扩散技术和复用子场的方法来显示灰阶和
假的轮廓提升。相对阴极射线管而言，在运动的图像中，你会发现人脸边缘会有
一些错误的彩色。
17． 显示灰阶测试图形时（在水平或者垂直方向亮度逐渐变化），你会发现相邻的两阶
亮度不均，这是复用子场、显示负载矫正和电解引起的。
18． PDP 屏前板是玻璃，安装时要注意屏是否放置到位，若放置不到位就直接安装，
可能会导致屏破裂。
19． 安装屏时使用的螺丝务必使用原规格，以免出现规格不匹配导致屏的损坏，特别
要防止螺丝过长、过大。
20． 装卸时要注意防尘，特别要避免脏物落入屏和玻璃之间，以免影响收看效果。
21． 后机壳对应电源板位置上帖有一片绝缘片，是用来进行冷热地隔离，装卸时要注
意保持完整，以免造成安全隐患。
22． 除等离子屏以外，玻璃也是一个高价值的部件，其具备防辐射、调整色温等功能，
也务必小心处理。
2、屏坏点判别及标准
目前我司生产的PDP 对坏点的判断依据如下：
2.1、PS－42D8 型:
本产品可能出现如下图1 三种坏点：亮点（一直亮着）、暗点（不发光点）、闪烁点（一
直闪烁点），但是不能超过表1 规定，否则则认为不合格。
- 3 -
H
W
W/4 W/2 W/4
H/4
H/2
H/4
W
W/4 W/2 W/4
Zone B
Zone A
H
H/4
H/2
H/4
图1 不良点
表1 三种坏点标准
类型 区域A 区域B 备注
暗点 不多于2 个 不多于8 个
亮点 不多于1 个 不多于2 个
闪烁点 不多于1 个 不多于2 个
A、B 两个区域的坏点
总数不得超过8 个，
两坏点之间的距离不
得小于15mm
2.2、PH－50D8 型:
本产品可能出现图2 的三种坏点：亮点（一直亮着）、暗点（不发光点）、闪烁点（一
直闪烁点），但是不能超过表1 规定，否则则认为不合格。
图2 不良点
表2 三种坏点标准
序
号
类型 区域A 区域B 备注
1 暗点 不多于4 个 不多于10 个
2 亮点 不多于1 个 不多于3 个
3 闪烁点 不多于1 个 不多于3 个
A、B 两个区域的坏点总数不得超过14
个，两坏点之间的距离不得小于10 mm
Zone B
Zone A
- 4 -
调试方法
PS-42D8、PH-50D8 的调试部分只有一项白平衡调整，其他都不必调试，且供售后维修的
软件一般都已将白平衡的值屏蔽起来，软件升级后不用再作调试；若有遇到更换主板等特殊
情况要调整时，方法如下：
1． 白平衡调整分TV/AV、VGA、YPbPr 三种通道来分别调整，先调TV/AV，再调VGA，而
后调YPbPr；
2． 分别选择对应的通道，连续按工厂遥控器的工厂(用户遥控器的右下角键未露出)
后，再连续顺序按小键盘的左键、右键、确认键，就可进入工厂设置菜单；
3． 用右键，选择校正菜单（如下图所示），其中的白平衡调整和YPbPr 白平衡调整既是
用来白平衡调整，其中TV/AV 和VGA 直接调第一项白平衡调整即可，YPbPr 的白平衡
则调第二项：
4． TV/AV 及VGA 的白平衡调整：选择菜单中的”白平衡调整”项，进入后(如下图所示)，
保持RCUT 不动，调整GCUT 和BCUT，调整暗区的白平衡；保持RGRV 不动，调整GGRV
软件发布
时间
软件版
本号
PW181 内
部测试信
号，可用
来进行故
障判断
- 5 -
和BGRV，调整亮区的白平衡；反复几次以上步骤，使图像白平衡正常.
5． YPbPr 白平衡调整：选择菜单中的“YPbPr 白平衡调整”项,进入后(如下图所示)，调
RCUT、BCUT 即可。
6． 注意：工厂菜单中除以上两项用来调白平衡外，校正菜单中的5、6、7 项（测试图
案、颜色配置、纯色灰度）可用来作故障判断外，其余项目请不要对其进行调整，否
则可能导致机器工作异常。
软件升级方法
我司推出的等离子电视PS-42D8、PH-50D8 具备有RS-232 软件升级接口，软件升级的步
骤如下：
1．选用一串口连接线（如下图所示），要求是两头都是母的，且两头的2、3 脚交叉连接；
2．用串口线连接PC 与PDP，PDP 置为关机状态；
3．打开升级软件文件夹，双击FlashUpgraderNT(window 2000/XP/NT 下使用)
- 6 -
或FlashUpgrader(window 98 下使用)，
程序运行后出现如下界面：
根据电脑的特性进行串口设定（COM Port ）选择对应的串口（如不能烧写可换为其它串口），
Baud 选择115200，并选择Reset Target After Download，点击flash 按钮, 即可运行。其他各
项设定，参照上图（系统已默认，一般不必更改）。
4． PDP 开机，烧写程序开始运行；
- 7 -
5．烧写完毕后，cancel 按钮会变为flash，关掉主电源重新开机即可；
注意：在烧写过程中不要断电或关机，否则可能导致flash 无法再烧写。
PS-42D8 系列等离子电视工作原理介绍
等离子平面屏幕技术为最新技术，而且它是高质图象和大纯平屏幕的最佳选择。等离子
显示屏PDP 是一种利用气体放电的显示装置，这种屏幕采用了等离子管作为发光元件。PDP
面板是由许多像素单元（等离子管）组成的，如目前销售的42”pdp 就是由852*480 个像素单
元组成的，同时每个像素单元又包含有三种次级像素，每个像素就是一个等离子管，它们分
别呈红、绿色、蓝色，见图一所示。每个等离子对应的每个小室内都充有氖氙气体。在等离
子管电极间加上高压后，封在两层玻璃之间的等离子管小室中的气体会产生紫外光，从而激
励平板显示屏上的红绿蓝三基色荧光粉发出可见光。每个离子管作为一个像素，由这些像素
的明暗和颜色变化组合，产生各种灰度和色彩的图像，与显像管发光很相似。等离子体技术
同其它显示方式相比存在明显的差别，在结构和组成方面领先一步。其工作机理类似普通日
光灯，电视彩色图像由各个独立的荧光粉像素发光综合而成，因此图像鲜艳、明亮、干净而
清晰。另外，等离子电视最突出的特点是可做到超薄，并轻易做到40 英寸以上的完全平面大
屏幕，而厚度不到100 毫米（我们的PS-42D8 的厚度仅为79mm，是目前市场上最薄的）
图一 像素单元结构
厦华PS-42D8 系列等离子电视，是厦华自行开发的等离子数字电视。在主芯片方面，
该机型采用了Pixelworks 公司的PW181，
总线电极
电介质
氧化镁层 ITO 电极
隔板 荧光粉
地址电极
前面板
背板
- 9 -
其中：
视频解码器: VPC3230 逐行转换: PW1230
AD 转换和DVI 接口:AD9887 音频处理:MSP3440
伴音功放：TI 的D 类功放Tpa3001 3D Y/C 分离：uPD64083
CCD/V-CHIP 解码：Z86229（仅用于北美机）
下面介绍一下PS-42D8 系列机型的基本工作流程：
本机为双MCU 控制方案，其中主MCU 为PW181（N501）：负责控制主板上的各芯片工
作（包括图像处理、通道切换、图象显示等）、接受红外遥控、控制待机、控制辅助CPU、
菜单显示、图像效果调试等主要功能；辅助CPU 为SDA555X（NM5）：负责伴音处理（包括
音量调节、高低音控制、立体声解码）、搜台控制、按键、3D Y/C 分离（只对N 制机有效）
以及外销机的图文、CCD/V-CHIP 解码等功能。两MCU 之间依靠X708 的INT（中断）、
S1(RXD)、S2（TXD）三脚建立联系。
2、声音部分：
本机型采用双一体化高频头（含高频与中放电路），天线接收到的信号送入主高频头
TUNER1，主高频头包含了高频分配器，RF 信号由此分出一路供给高频头TUNER3 使用，
其中TUNER1 的14 脚为高频分配器部分的供电（+5V）。高频头受辅助MCU NM5 （SDA、
SCL）控制，选择合适的频道，进行正确的制式切换，经高放及中放解码后，输出视频信号
和音频信号。TUNER1 的输出信号送给解码器N102 作为主画面显示，TUNER3 的则送给解
码器N302 作为双画面的副画面显示。
音频信号直接送入音频处理器 NM2 MSP3440，同时双路高频头都将其第二伴音中频
信号SIF，送入NM2 进行处理（用来作为立体声解码或自动音量控制）。NM2 具备了音频通
道切换开关，主板的VGA/DVI/YPrPb 的音频输入经N3 选择切换后，与TV、AV 的音频信号
同时送入NM2，在这里进行选择切换，选中的音频信号一路经音量及高低音控制后分左右声
道送入伴音功放TPA3001 进行放大处理，然后送入喇叭重现声音；一路也分左右声道送入耳
机功放NM9 TDA7053，进行功率放大后，输出到耳机插座供使用耳机时收听，其音量由
NM5 的50 脚产生的PWM 信号控制；还有一路则作为AV out 的伴音由视频板输出。
MSP3440 的框图如下所示：
- 10 -
本机型中MSP3440 的主要引脚说明：
2、3：SCL、SDA，用来控制IC 的工作；
27、28：输出给伴音功放的右、左声道；
33、34：耳机伴音右、左声道；
36、37：AV OUT 伴音右、左声道；
47、48：主板送过来的伴音左、右声道；
50、51：AV IN 伴音的左、右声道；
53、54：次通道TV 的左、右声道
56、57：主通道TV 的左、右声道
67、69：主、次通道TV 的SIF 输入
伴音供放TPA3001 为一单声道高效的D 类供放，在无散热片的情况下其输出功率可达
20W，具有过流、过热保护功能，当对地输入短路时，会自动保护，停止输出，若短路解除后
重新开机，则可恢复正常。因此在带电拨插音频线时（不建议此种操作方式）若不小心短路
而导致无声音，重起即可。
3、图像部分：
AV 与SVHS 的Y 信号共用一个通道，SVHS 优先，S 端子的识别由SVHS 插座送给NM5 的SID
电平决定，当SID 的电平为高电平时，系统识别为SVHS。TV 或AV 及YCRCB 的信号一同送入
数字解码器VPC3230（分别分两路送入N102 和N302）,进行通道切换并解码，解码成16bit
的CCIR601 信号，送给下一级信号处理进行处理。VPC3230 主要完成通道切换、4 行的Y/C
分离、彩色解码、图像效果调整等功能。
3．1、VPC3230 的框图如下所示：
其中:
71 脚作为SVHS 的C 信号输入；
72 脚VIN1 作为AV 的CVBS 或SVHS 的Y 输入；
73 脚VIN2 作为TV 信号输入；
75 脚VIN4 作为YCRCB 的Y 输入，用来作为YCRCB 的同步识别。
主通道：N102 解码后的CCIR601 格式的数字YCRCB 信号，送入逐行处理器N204 PW1230
进行隔行转逐行。VPC3230 送出的VD1_CLK、VD1_HSYNC、VD1_VSYNC、VD1_ACTIVE、VD1_FIELD
- 11 -
是用来进行模式识别的关键信号，若其中某路出现异常都可能导致该通道图像显示异常。
PW1230 除了隔行转逐行功能外，还具备了图像增强、3：2/2：2 电影模式转换等功能。主通
道的亮度、对比度调整也由此芯片完成，而色度和清晰度调整则由N102 完成。PW1230 处理
后输出24bit 的数字RGB 信号，送入N501 PW181 的V PORT 进行处理，其输出的VCLK（时钟）、
VVS（场同步）、VHS（行同步）、VPEN（使能信号）信号也是下级图像处理的基本依据。
单N 制的机型，本系列机型的主通道还增加了3D Y/C 分离功能——由ND02 Upd64083
完成，以提高图像质量。若是如此，则主通道的信号流程则会有所不同，TUNER1 送出的视频
信号和AV/SVHS 信号要先经开关电路ND01 切换后送入ND02 进行亮色分离，并输出Y 和C 信
号。对N102 而言，无论是TV 或AV/SVHS 最终都是以Y/C 的形式送入VIN1 和CIN 这个输入口，
在软件的设定上有所不同。
主通道的图文或CCD/V-CHIP 解码则由辅助CPU 来完成，视频信号直接送入NM5 的12 脚
供解码使用，解码后的图文或CCD/V-CHIP 信息则以R、G、B、FB 的形式输出，送给N102，
进行字符叠加。
次通道：VPC3230 解码后的CCIR601 信号直接送入PW181 的G PORT，由PW181 直接进行
处理，此通道的逐行转换由PW181 内部的逐行处理器完成，相对而言，PW181 的内部逐行处
理器的效果会比PW1230 的效果差一些，因此在双画面显示时，主画面的图像效果会比次画面
的好。次通道的亮度、对比度、清晰度、色度调整由N302 完成。
此通道的CCD/V-CHIP 解码由专用的21 行解码器N301 Z86229 来完成，解码后的信息也
同样以R、G、B、FB 的形式在N302 中叠加到图像内容上。
对于VGA 和YPRPB 来说，YPRPB1 与YPRPB2 通过N1 选择后，再与VGA 信号一同送入N402
进行通道选择，选中的信号送入N403 AD9887 的ADC 部分进行模数转换，生成24bit 的数字
RGB 信号送入PW181 的G PORT。VGA 的行、场同步信号直接送入N403，而YPRPB 的行、场同
步则由输入到N403 108 脚SOGIN 的Y 信号经AD9887 同步分离后取得。
同步切换开关如下图所示：
AD9887 同时具备了DVI 输入接口，输入的DVI 信号由AD9887 转换为48bit 的数字RGB
- 12 -
信号，送入PW181 的G PORT 进行处理。DVI 和VGA/YPRPB 的选择由AD9887 来进行切换。本
系列机型的某些外销机种还具备了HDCP 解密功能，密钥校验是通过PW181 的PORTA4、PORTA5
两从总线与播放设备进行的，每台机型有着自己独立的密钥，存储在EEPROM 中。
VGA 或YPRPB 的模式识别是由PW181 来完成的，其工作过程是：当所选择通道的信号输
入时，PW181 预先设定了AD9887 的同步选择，使其直接输出所需的同步信号直接送给PW181，
在PW181 内部对同步信号格式进行识别，识别后对照内部预存的模式表，获得一个最接近的
模式，调用其参数设定，返回来设定AD9887 的模数转换参数，使其最佳；并同时确认SCALER
的转换系数。
3．2、AD9887 的框图如下所示：
最后，不同通道的视频信号分别送入了主处理芯片PW181 的V PORT 和G PORT 进行处理。
PW181 具有画外画、画中画、多画面处理功能，只要是分别来自V PORT 和G PORT 的信号，
相互之间就可组成画中画、画外画。PW181 具有SCALER 功能，可对不同格式输入信号进行格
式转换，使其满足屏的格式要求，并最终以24bit 的RGB 信号输出。
PDP 屏的接口标准一般为LVDS（低压差分信号），因此PW181 输出的数字RGB 信号，还要
用LVDS 转换接口芯片N602 DS90C385（对于不同厂家的屏，此芯片可能不同）转化为LVDS
- 13 -
信号，再送给屏，供屏驱动。N602 的输出为四对差分信号和一对时钟信号，若某对差分信号
异常，则会直接导致图像显示异常，如某种颜色不正常。PW181 输出的PWRDOWN 信号用来控
制N602 的工作，低电平时工作。
PW181 同时也是主CPU，其程序储存在外接的flash N601 内，RS-232 的软件升级就是通
过PW181 对N601 的储存内容进行升级。菜单界面也是由PW181 产生，同时PW181 可产生自检
信号，可用来进行故障判断。
3．3、PW181 的框图如下所示：
以上就是该系列机型的信号流程介绍，注意每级间的HS（行同步）、VS（场同步）、CLK
（时钟）、PEN（使能）都是下一级芯片模式识别的基准，务必保证其正常工作。
整机的待机控制由PW181 完成，PW181 的PORTB3 输出的POWER-ON 信号用来控制电源板
的工作，当POWER_ON 为低电平时开机，高电平时待机，待机时电源只剩下5VSTBY 工作。
屏工作所需的VS 等电压，还受逻辑板输出的VS_ON 信号控制，高电平工作，当逻辑板接
收到正确的信号（时钟、同步、使能等）后，VS_ON 方可正确输出。PDP 屏的工作对电源的上
电时序要求特别严格，若是时序错误，可能导致屏无法正常工作。
- 15 -
不同屏的电路板分布图及各电路板的作用
1、42SD（型号：S42 SD-YD04，编号：335-42001-00）
部件名称 作用
电源板 提供整机工作的电源
逻辑板 将信号处理板送来的LVDS 信号转化为可供屏显示用信号
寻址电路 屏显示的寻址电路，直接驱动屏上的寻址电极（垂直电极，共852X3 电极）
X 驱动 X电极（水平公共、维持电极）驱动电路
Y 驱动 Y电极（水平扫描、维持电极，共480 电极）驱动电路
X 驱动板
电源板
Y 驱动板
逻辑板
寻址电路
- 16 -
2、50HD（型号：S50HW-XD02，编号：335-50001-00）
部件名称 作用
电源板 提供整机工作的电源
逻辑板 将信号处理板送来的LVDS 信号转化为可供屏显示用信号
寻址电路
屏显示的寻址电路，直接驱动屏上的寻址电极（垂直电极，共1366X3 电极），分上
下各半场分别驱动。
X 驱动 X电极（水平公共、维持电极）驱动电路
Y 驱动 Y电极（水平扫描、维持电极，共768 电极）驱动电路
Y 驱动板 电源板
X 驱动板
逻辑板
寻址电路
- 17 -
电路板的部件编号
信号处理板的组成：
部件编号
部件名称
PS-42D8 PH-50D8
主要器件及编号
主板 667-PHID8-01 667-PHSD8-01
N501 PW181-20 (353-01810-00)
N204 PW1230 (353-12300-00)
N403 AD9887-140 (353-98870-30)
N102/N302 VPC3230D (353-32300-80)
N602 DS90C385MTD (353-03850-20)
N601 AM29LV800BT-90E(353-29800-10)
视频处理板 667-PH42D8-40 667-PH50D8-40
NM5 SDA555XFL (352-05550-20)
NM2 MSP3440G (353-34400-00)
NM9 TDA7053AT (353-70530-70)
视频板 667-PS42D8-70
TUNER1 JS-6B1/112A2-A2(590-40425-00)
TUNER3 JS-6B1/111C6 (590-40422-00)
伴音供放板 667-PS42D8-24 NA01/NA02 TPA3001D (353-30010-10)
转接板 667-PS42D8-46
遥控器部件 301-UPS42D8-09
按键板部件 667-PH42D8-05 667-PH50D8-05
电源滤波板部件 667-PH42D8-51 667-PH50D8-51
主板部件 视频处理板部件
视频板部件
转接板部件 伴音功放板部件
- 18 -
将X709 的8 脚
（PS-ON）对地短
路，再测电源
常见故障检修图
1． 三无（无光栅、无图像、无声音）：
电源指示灯是否亮
亮 不亮
不正常 正常
正常 不正常 正常 不正常
JI
正常 不正常
正常
注：PDP 的电源具备过流、过压等保护功能，若某路电源出现过流、过压，电源将出现保护而引起无输
出。
三无
查5V-STBY
断开电源板和
信号处理板的
连接，再测试
5V-STBY
断开主板和
视频处理板
的连接X2，
再判断是哪
块板工作不
正常
电源板问
题
查电源特别
是D3.3V
N501 工
作异常
查N501 的
供电、晶振
及N601
拔去X709
再测电源
查N501
和N601
查N102 、N204 、
N302、N403 的供电
晶振及总线
某路电源
出现短路
电源板问题
- 19 -
2． 有声音无图像：
有 无
无 有
正常
不正常
正常 不正常
正常 不正常
注：
原先自上电的软件，PW181 工作异常时，SDA555X 可能出现单独开机状态，此时的故障现象经
常是有声音无图像。
屏自检方式设定：
42”SD 屏(S42SD-YD04)：将逻辑板上的SW2001 的2、4 下拨，3 上拨；
50”HD 屏(S50HW-XD02)：将逻辑板上的SW2001 的1、4 下拨，2、3、5、6 上拨；
检测后要注意将其恢复原状。
有声音无图像
有无开机界面
试其他通道是
否都无图像
N501 及
外围
转入4 检
查程序
若有示波器，可
先检测X604 的
信号波形
拔去X604 、X709，将
X709 的8 脚对地短路，
逻辑板的开关置为自检
信号，开机是否出现白屏
查N601 的输入
信号和供电
屏损坏
N601 损坏查N501 及其输
出部分电路
- 20 -
3． 有图像无声音
伴音功放板上XA04 是否有输出
无
有
有 无
是 否
4． 某种通道工作不正常
1) AV 无图像
首先利用双画面功能判断是主画面还是副画面有问题
主通道无图像:
有 无
否 是
否 是
有图像无声音
音箱坏
伴音功放或其外围电路有问题，检查供电，
SHUTDOWN 脚控制是否正常；是否存在输
出短路等可能导致保护启动的可能
测量伴音功放第2 脚
有无信号输入
测量NM2 相对应
的当前通道的伴
音输入是否正常
MSP3440 或其外
围电路的问题
顺着输入音频信号的通道
检查各级电路
测N102 第72 脚是否
有信号输入
测R143~R148 等排阻输出的Y、
C 信号及行场等信号是否正常
由AV 插座至
N102 通路有问题
测R209~R213 等排阻看
PW1230 输出是否正常
N102 或其外围
电路有问题
N204 PW1230 或其
外围电路有问题
N501 PW181 或其
外围电路有问题
- 21 -
次通道无图像：
有 无
是 否
2) YPRPB 或YCRCB 无图像
是 否
YCRCB YPRPB
同时
正常 不正常
测N302 第72 脚是
否有信号输入
测R340~R345 等排阻输出的Y、
C 信号及行场等信号是否正常
由AV 插座至
N302 通路有问题
N501 PW181 或其
外围电路有问题
N302 或其外围
电路有问题
测试是否YPRPB/YCRCB1 与
YPRPB/YCRCB2 两通道同时无图像
N1 及接口
电路问题
判别是YPRPB 或
是YCRCB 问题
查N302 及
其外围
输入VGA 信
号是否正常
查N402（包括开关
电压HDTV_SEL）
及C410
查N403 及其外围
N501 的G PORT 及
外围
- 22 -
3) TV 无图像
正常 无图像
正常 不正常
正常 不正常
.
正常 正常 不正常 正常 不正常
正常
调出双画面，将另一画面也置
为TV，确认该画面是否正常
输入一AV 信号，确认
AV 通道是否正常
查TUNER1 部分
的供电、总线及视
频输出电路
查N102 的输出信
号（行、场同步，
时钟，使能等信号）
N204 及其
外围电路
有问题
N501 V PORT
部分其外围电
路有问题
输入一AV 信
号，确认双画面
的AV 是否正常
输入VGA 信
号是否正常
N702 的电
压是否正常
N102 的输入电
路或接口问题
查N204 的输出
信号（行、场同
步，时钟，使能
等信号）
查N102 及
其外围
TUNER 部
分的供电
或NM5 问
题
按2 顺
序检查
各部件板之
间的连接是
否可靠
- 23 -
4) VGA 无图像
是 否
正常 不正常 可以 不可以
正常 不正常
5) DVI 无图像
若是VGA 工作正常，则只要查插座X401 与N403 的连接，及N403 的工作情况即可。R414 为其
输入匹配电阻，若出现问题会导致DVI 图像异常。
5． 画面异常：
色异，以下几种故障可能导致此现象：
X604 的LVDS 某差分线对（RX0+/-，RX1+/-，RX2+/-，RX3+/-）异常，会导致缺色（不完
全丢色）；
R550~R555 电阻排故障，会导致所有通道的图像相应的灰度上丢失相应的颜色，用PW181
的自检信号检测故障依旧；
R419、R421、R425、R427、R431、R432 电阻排故障，会导致VGA/YPRPB/DVI 通道的图
像相应的灰度上丢失相应的颜色；
R415、R418、R422、R424、R429、R430 电阻排故障，会导致DVI 通道的图像相应的灰度
上丢失相应的颜色；
R342、R343、R344、R345 电阻排故障，会导致次通道的TV/AV/YCRCB 图像相应的灰度上
丢失相应的颜色或亮度异常；
R207、R208、R209、R210、R211、R212 或R145、R146、R147、R148 电阻排故障，会导
致主通道的TV/AV 图像相应的灰度上丢失相应的颜色或亮度异常；
N203 与N204 之间的连接不良，也会导致主通道的TV/AV 图像出现竖条的图像异常；
输入YPRPB 信号是否正常
是否可识别VGA 的模式
（屏幕右下角OSD）
测N403 的81、82 输
入的行场同步信号
查N402
及外围
查N403 及其外
围，特别是其输
出的时钟、行同
步、场同步及使
能信号
查N403
及其外围
输入接口
电路问题
双画面时，两画面
TV 的图像是否正常
查N501 的
GPORT 的输
入部分电路
- 25 -
二、故障诊断：
1．屏不亮：
a,由电源滤波板到电源板上供电的插座是否有插好。没有的，插好插座。
b.检查电源板上的保险丝是否开路，是的话更换一个好的保险丝。
c.拆下我们的主板和视频处理板，将电源板上的插座CN802 第4 脚POWER_ON/OFF 接地:
再将逻辑板上的拨动开关SW2001 由原来的外部模式（1、2、4 上，3 下）拨成内部模式（1、3
上、2、4 下）：
接通电源，看屏是否点亮。如果屏能输出一个正常的全白场信号，则为我们的主板或视频处理板
问题，另行处理。
d.如果屏仍然不亮，先更换电源板，看问题是否解决.
e.如果更换电源板仍然无法解决问题，则为屏的问题，更换整块屏处理。
即此焊点
SW2001
- 26 -
2．屏上出现一条，或数条水平不亮线：
检查Y 驱动板与Y BUFFER 之间的插座是否有插好，没插好的话，重新插好插座，如果已经是插
好的，根据暗线出现在屏的上、下部，更换Y BUFFER(上、下)
3．屏上出现一条，或数条比边上其余的水平线亮的多的水平亮线：
检查Y 驱动板与Y BUFFER 之间的插座是否有插好，没插好的话，重新插好插座，如果已经是插
好的，根据暗线出现在屏的上、下部，更换Y BUFFER(上、下)
4．屏上出现一条垂直的不亮线，或整块垂直的不亮块
a. 如果是出现一条不亮的垂直线，则是COF 有问题。
b. 如果是出现整块垂直的不亮块，先检查是否是COF 与逻辑BUFFER 之间的连接插座有问题，
如果没问题，检查逻辑BUFFER 与逻辑板间的连接插座是否正常。如果也是正常的，更换逻
辑BUFFER。最后，更换完，如果还不能解决问题，更换逻辑板。
- 27 -
5.屏上显示一种单色信号时，出现垂直的一条或数条其它颜色的亮线：
a.如果是出现一条其他颜色的垂直亮线，则是COF 或是屏有问题。
b.如果是出现整块垂直的其他颜色亮块，先检查是否是COF 与逻辑BUFFER 之间的连接插座有问
题，如果没问题，检查逻辑BUFFER 与逻辑板间的连接插座是否正常。如果也是正常的，更换逻辑
BUFFER。更换完，如果不能解决问题，更换逻辑板，最后，如果换完逻辑板问题还在，就是COF 有问
题。
6．屏上出现与上述情况都不同的异常的亮点，亮块等：
a. 检查逻辑BUFFER 板与COF 板之间逻辑板与逻辑BUFFER 板之间的插座是否连接好。
b. 更换逻辑BUFFER 板，如果无法解决，更换逻辑板。如果问题还在，就是COF 有问题。
SERVICE
MANUAL
- 1 -
Note: This maintenance manual is intended only for the reference of the maintenance people. Please
pay attention to the following points before carrying out the maintenance work.
Safety Instructions
Please read the “Points for attention for the Maintenance & Repair of PDP”and “Criterion for Identifying
the Defects on Screen” as below, before inspecting and adjusting the TV set.
1. “Points for attention for the Maintenance & Repair of PDP”
To avoid possible danger, damage or jeopardy to health and to prevent PDP screen from new
damage, the maintenance people must read the following carefully. If they ignore the following
warnings, there will be deathful risks:
1). Screens vary from one model to another and therefore not interchangeable. Be sure to use the
same type of screen in the replacement.
2). The operation voltage is approximately 350v for PDP module (including screen, driving circuit,
logic circuit and power module). If you want to conduct maintenance work on PDP module
when the set is in normal operation or just after the power is off, you must take proper
measures to avoid electric shock and never have direct contact or touch with the circuitry of
the working module or metal parts. That’s because within a short time relatively high voltage
still remains on the capacitor of the driving part even after the power is off. Make sure to begin
relevant maintenance operation at least one minute after the power is off.
3). Don’t apply on the module any power supply that is higher than the specification.
If the power supply used deviates from the value given in the specification, there might be a
possibility of leading to fire or damage to the module.
4). Never have operation or mounting work under unsuitable environment such as areas in the
vicinity of water – bath room, laundry, water chute of kitchen – sources of fire,
heat-radiation parts or direct exposure to sunlight. Otherwise there will be kickbacks.
5). In case foreign substances such as water, liquid, metal slices or others fall into the module
carelessly power must be cut off immediately. Keep the module as it is and do not move
anything on the module. Otherwise it might be possible to contact the high voltage or cause
shock short circuit so that it may lead to fire or electric shock.
6) If there is smoke, abnormal smell or sound from the module, please cut the power off
immediately. Likewise in case the screen doesn’t work when the power is on or during the
operation, please also cut off the power at once. No more operation in this case.
7) Do not remove or plug its connection wire when the module is in operation or right
after the power is off. That’s because there remains a relatively high voltage on the
capacitor of the driving circuit. If there is a need to remove or plug in the connection wire,
please wait at least one minute after the power is off.
8). Considering the module has a glass faceplate, please avoid extrusion by external force lest it
- 2 -
should cause glass breakage that may get people injured. Two people are needed in
cooperation to move this module lest contingency takes place.
9). The complete TV set is designed on the basis of full consideration of thermal dissipation by
convection, with the round hole on the top for heat emission. To avoid overheat, please do
not have any covering on the hole during normal operation and never put it in the place
where the space is narrow and in bad ventilation.
10). There are quite a number of circuits in PDP that are integrated ones. Please be on guard
against static electricity. During maintenance operation be sure to cover yourself with
anti-static bag and before operation make sure to have it sufficiently grounded.
11). There are a big number of connection wires distributed around the screen. Please take care
not to touch or scuff them during maintenance or removing the screen, because
once they are damaged the screen will fail to work and it’s not possible to repair it.
12). Connector for the circuit board of the screen part is relatively fine and delicate. Please take
care in the replacement operation lest it should get damaged.
13). Special care must be taken during transportation and handling because strenuous vibration
could lead to screen glass breakage or damage on the driving circuitry. Be sure to use a
strong outer case to pack it up before transportation or handling.
14). Please put it for storage in an environment in which the conditions are under control so as to
prevent the temperature and humidity from exceeding the scope stipulated in the
specification. For prolonged storage please cover it with anti-moisture bag and have them
piled and stored in one place. The environmental conditions are tabulated as below:
Temperature Scope for operation 0～50centigrade
Scope for storage -15～60centigrade
Humidity Scope for operation 20%～80%
Scope for storage 20%～80%
15). If a fixed picture is displayed for a long time, difference in its brightness and color may occur
compared with movable pictures. But it doesn’t show any problem and the reason is that
there is reduced density of fluorescent powder in the former. On the other hand, even if
changes take place in the picture, it can keep its brightness for
a period of time (several minutes). It’s a feature inherent with plasma and it’s not abnormal.
However please try as much as possible to avoid showing a still picture of high brightness for
a long time during operation.
16). As a digitalized display devise, this module is provided with error diffusion technology and the
- 3 -
gray scale and false enhancement of contour can be displayed by reusing of sub-field. As
compared with cathode ray tube, it can be found in the moving picture that at the brim of the
face of a person there are some wrong colors.
17). During the display of graph (indicating the gradual change in brightness horizontally or
vertically) resulting from gray scale test it can be found that the brightness for the two
adjacent levels is uneven. This is caused by the reuse of sub-field, the display of load
rectification and the eletrolyzation.
18). The screen front plate is of glass. Please make sure that the screen has been put in place
during erection. If it is not in place before the erection begins it may lead to screen crack or
breakage.
19). Make sure the screw used in the mounting of the screen is of the original specs lest it should
cause damage to the screen due to mismatch. Special care should be taken not to use too
long or too big screw.
20). Care must be taken to guard against dust during assembling or dismantling, especially to
avoid dirt from falling in between the screen and the glass lest it should harm the receiving
and viewing effect.
21). There is piece of insulator stuck on the rear chassis corresponding to the power supply
board. It is used to isolate the cool part from the hot part. Please take care to keep it intact
lest it should become a potential safety trouble.
22). In addition to plasma screen, the glass is a part of high value. It has such functions as
anti-radiation, adjustment of color temperature etc. Please handle it carefully.
2. “Criterion for Identifying the Defects on Screen”
The PDP produced by our Company at present uses the following criterion for identifying the
defective points:
2.1、Model PS－42D8:
There may appear three kinds of defective points for this model as shown in Fig.1, i.e.,
bright spot (remain bright); dark spot (non-illuminating); flickering spot (continuously
flickering).
However they should not exceed the specification as in table 1. Otherwise the product shall
be deemed as sub-standard.
- 4 -
H
W/4 W/2 W/4
H/4
H/2
H/4
W
W/4 W/2 W/4
Zone B
Zone A
H
H/4
H/2
H/4
Figure 1 Defective Points
Table 1 Criterion for Three Kinds of Defective Points
Kind Area A Area B Remark
Dark spots No more than 2 No more than 8
Bright spot No more than 1 No more than 2
Flickering spot No more than 1 No more than 2
Total number of
defective points in A
and B shall not
exceed 8. The
distance between
two defective points
shall not be shorter
than 15mm.
2.2. Model PH－50D8:
There may appear three kinds of defective points for this model as shown in Fig.2 --
bright spot (remain bright); dark spot (non-illuminating); flickering spot (remain flickering).
However they should not exceed the specification as in table 2. Otherwise the product shall
be deemed as sub-standard.
Figure 2 Defective Points
Table 2 Criterion for Three Kinds of Defective Points
Zone B
Zone A
- 5 -
Method of Debugging
For Models PS-42D8 and PH-50D8, the debugging part lies only in the white balance adjustment.
Nothing else should be adjusted and the maintenance software supplied for after-sale purpose has
normally shielded the value of white balance i.e., no more adjustment is needed when upgrading
the software. In case of special circumstances where the main board is replaced following method
can be adopted:
1). The white balance adjustment is made respectively in three ways - TV/AV、VGA、YpbPr. First
adjust TV/AV, then VGA and YpbPr at the last
2). Select corresponding channels respectively. After successively press the keys on the production
plant’s remote control (the key at the right hand lower corner doesn’t show up), go on to press
the left key, right key, confirmation key on the small keyboard one by one and then it’s possible
to enter the menu set up in the plant.
3). Use the right key to select and calibrate the menu. The white balance adjustment and YpbPr
white balance adjustment are for the purpose of white balance adjustment. For the white
balance adjustment of TV/AV and VGA it’s OK just directly adjust the first item whereas for
YpbPr adjust the second item.
4) For the white balance adjustment of TV/AV and VGA: select the item of “white balance
adjustment” from the menu. When it’s entered (as shown in the fig. Below), keep RCUI
immovable and adjust GCUT and BCUT so as to adjust the white balance of the dark area. For
the adjustment of white balance of the bright area, keep RGR immovable and then adjust
GGRV and BGRV. Repeat the above steps several times until the picture is normal in white
balance.
For the white balance adjustment of YpbPr: select the item of “white balance adjustment” from
the menu. When it’s entered (as shown in the fig. Below), adjust RCUT、BCUT and it’s done.
Item Kind Area A Area B Remark
1 Dark spots No more than 4 No more than 10
2 Bright spot No more than 1 No more than 3
3 Flickering
spots
No more than 1 No more than 3
Total number of
defective points in A
and B shall not
exceed 14. The
distance between
two defective points
shall not be shorter
than 10mm.
- 6 -
5).Note: Except for the two items in the plant setup menu as above used for the white
balance adjustment and the items 5,6,7 (for test of pattern, color collocation and
degree of pure gray) in the calibrated menu that can be used to shoot trouble, no
adjustment should be made for the other items. Otherwise it may cause
abnormality to the set. The internal test signal of PW181 can be used for
troubleshooting.
Method of software upgrading
The plasma TV models PS-42D8 and PH-50D8 launched by our company are equipped with RS-232
interface for upgrading that is carried in the steps below:
A. Select a connection wire of serial port (see the figure below) which is required to
have a notch on its both ends and also the pins 2 and 3 on the two ends are
cross-connected.
B. Use the serial port connection wire to connect PC with PDP and set PDP to the off
position.
C. Open the folder of the upgrading software and double click the FlashUpgraderNT
(on condition of window 2000/XP/NT)
- 7 -
or the FlashUpgrader (on condition of window 98)
After running the programs the following interfaces will appear:
Based on the features of computer set up the serial port (COM Port) and select
corresponding serial port (if it’s not possible to burnt-write other serial port can be used
instead). Baud-select 115200 and then select Reset Target After Download. Hit flash
press button and it’s ready to operate. For the setup of other items please refer to the
figure above (already defaulted by the system so it’s normally unnecessary to alter)
A. Switch on PDP and it begins to run the burnt-write program;
- 8 -
B. Once it’s over with burnt-write, the cancel pushbutton will become flash. Switch off
the main power and then to switch on the TV set again.
Note: Do not switch the power or the set off in the course of burnt-writing. Otherwise it
may result in the inability of the flash to burnt-write again.
- 9 -
Briefing on the operation principle of the plasma TV series PS-42D8
Plasma plane screen technology represents the state-of-the-art and it’s also the best choice for high quality picture
and large purely place screen. Plasma display screen PDP is a display unit employing gas discharge. This screen uses
plasma tube as its light emission component. The faceplate (panel)of PDP consists of many image elements (plasma
tubes) for example, the 42”pdp now on the market consists of 852*480 image elements. Each image element in turn
consists of three kinds of image sub-elements. Each image element is actually a plasma tube. These tubes are present
respectively in red, green and blue colors, as shown in fig. I. Each small chamber that corresponds to each plasma tube is
filled with neon and xenon gases. After applying high voltage between the plasma electrodes, the gases in the small
chambers of the plasma tubes sealed in the two layers of glass will produce ultraviolet so as to excite the three basic color
(red, green and blue) fluorescent powder to emit visible light. Each plasma tube acts as an image element. From the
composition of these image elements in different brightness, darkness and colors result the pictures and images of
various grays and colors, which is very similar to the light emission of display tube. Plasma technology is obviously
different form other display methods and is more advanced in structure and formation. Its working principle is similar to
normal daylight lamp. The TV color picture is composed of the light emitted from various independent fluorescent powder
image elements and therefore the picture is fresh and gaily colored, bright, clean and clear. Furthermore the most
outstanding feature of plasma TV is that it can be made super thin and it’s easy to make TV sets of more than 40” with
completely plane big screen but in thickness less than 100 mm (Our Model PS-42D8 is only 79mm thick and it’s the
thinnest in the market at present.)
Figure I Structure of Image Element
Plasma TV model PS-42D8 series of XOCECO is designed and developed by XOCECO itself. In
terms of the main CMOS chip this series of TV set employs PW181 made by Pixelworks Company.
Bus
dielectric
ITO electrode
clapboard Fluoresce powder nce
Address
electrod
Front panel
Back board
Magnesia layer
- 11 -
Among which:video decoder:VPC3230 Non-interlace conversionW1230
Ad conversion and DVI interface :AD9887 Audio treatment:MSP3440
Sound power amplification type power amplification of TI : Tpa3001
3D Y/C separation:uPD64083
CCD/V-CHIPdecoder:Z86229（For North America only）
Below is a short introduction to the basic work process flow of model PS-42D8series:
This TV model is based on dual MCU control of which the main MCU is PW181（N501, taking care
of the operation of various chips (including image treatment, channel switching, image display etc.), infra
red remote control receiving, the standby control, the control of auxiliary CPU, menu display, debugging
of picture effects and other major functions. The auxiliary CPU is SDA555X（NM5, which is responsible
for sound treatment (including volume adjustment, control of alt and base sound, stereo decode), station
searching control, push button, separation of 3D Y/C (valid only for system N) as well as the
CCD/V-CHIP decoding for the text for oversea sale TV sets etc. Connection between two MCU is made
by means of three pins of X708, i.e., INT (interruption), S1(RXD), S2（TXD）
2.Volume of sound
This model employs double integrated tuner (including high frequency and medium amplification
circuits). The signal received by antenna is fed to the main tuner, TUNER1, which contains a high
frequency distributor, from which RF signal is shunt to supply to TUNER3 for use. Pin 14 of TUNER1
is for the power supply of high frequency distributor (+5v). Tuners are controlled by auxiliary MCU
NM5 （SDA、SCL）to select proper channel and carry out correct switching of systems. After high
amplification and medium amplification decoding, video signal and audio signal are output. The
output signal of TUNER1 is fed into decoder N102 as the display of main picture whereas the output
signal of TUNER3 is fed into decoder N302 as the display of the auxiliary picture for dual picture.
Audio signal is directly fed into audio frequency processor NM2 MSP3440. At the same time dual
way tuners all send their medium frequency signal of the second sound to NM2 for treatment (used
for decoding of stereo or automatic sound volume control). NM2 is provided with the switching over
device for audio frequency channels. Audio input of VGA/DVI/YprPb of the main board, after the
switching-over as selected by N3, is fed together with the audio signal of TV and AV into NM2, where
switching over is selected. The selected audio frequency signal is made use of in the following three
ways. One way is, after being subjected to the control of volume and alt and base sound, fed
separately through left and right sound channels into sound power amplifier TPA3001 for
amplification. Then it is fed into the loudspeaker for sound reproduction. Another way is also fed
separately through left and right sound channels into earphone power amplifier NM9 TDA7053 for
amplification before being output to earphone socket for listening, of which the volume is controlled
by PWM signal produced by pin 50 of NM5.
The remaining way is output through video board as AV out
The block diagram of MSP3440 is as follows:
- 12 -
2, 3:SCL、SDA，for the control of IC operation;
27,28utput to the right and left channel of sound power amplifier;
33,34:right and left channel of earphone sound;
36,37:AV OUT right and left channel of sound;
47,48:right and left channel of sound fed from main board;
50,51:AV IN right and left channel of sound;
53,54:right and left sound channel of sub-channel TV;
56,57:right and left sound channel of main channel TV;
67,69:SIF input of main and sub channel TV
Sound power amplifier TPA3001 is an amplification of mono-channel high efficiency D type power.
Under the condition of no heat dissipation its output power can be as high as 20 w. It has the functions of
over current and overheating protection. Automatic protection comes in when the input to the ground is
short-circuited. Then output is stopped. After the removal of short circuit, switch the set again and it
restores to normal. Therefore if the set becomes soundless due to the short circuit caused in carelessly
pulling out or plugging in the audio frequency wire (it is certainly not recommendable to do so), just
switch it on again and no big deal.
3. Picture and image:
Y signal of AV and SVHS shares the same channel. SVHS has priority. Identification of terminal S is
determined by electric level SID fed from SVHS socket to NM5. When the electric level of SID is of high
value, the system is identified as SVHS. Signals from TV or AV and YCRCB are altogether fed into
digital decoder VPC3230 (sent separately in two ways to N102 and N302). Channel switching is carried
out. They are decoded into 16bit CCIR601 signal to be fed into the processor of lower level for treatment.
VPC3230 mainly functions to switch over channels, separate Y/C
of 4 lines, decoding of colors and adjustment of picture effect.
3．1 The block diagram of VPC3230 is shown below:
- 13 -
In which: Pin 71 is used for the input of C signal of SVHS;
Pin 72 VIN1 is used for the input of Y signal of CVBS or SVHS of AV;
Pin 73 VIN2 is used for the input of TV signal;
Pin 75 VIN4 is used for the input of Y signal of YCRCB to synchronously identify
YCRCB.
Main channel: The digital YCRCB signal in the format of CCIR601 after being decoded in N102 is
fed into non-interlace processor N204 PW1230 for treatment from alternate-line into non-interlace.
VD1_CLK,VD1_HSYNC VD1_VSYNC, VD1_ACTIVE and VD1_FIELD sent from VPC3230 is used as a
key signal to identify modes. If certain channels become abnormal the corresponding pictures will also
become abnormal. In addition to the function PW1230 has to process the signal from alternate-line into
non-interlace, it can also function to enhance the picture and convert the movie modes 3:2/2:2. The
adjustment of brightness and contrast of the main channel is performed by this chip whereas the
adjustment of chroma and definition is performed by N102. The digital 24 bit RGB signal output from
PW1230 after treatment is fed into V PORT of N501 PW181 for further processing. The signals of VCLK
(clock)、VVS（field synchronization）、VHS（line synchronization）、VPEN（enable signal）are the basic
reference for the image processing of lower level.
For TV set of mono N system, this series has an additional 3D Y/C separation function in the main
channel, which is performed by ND02 Upd64083 so as to enhance the quality of the image.
In this case the signal flow process of the main channel is different. Video signal and AV/SVHS signal
sent from TUNER1 first undergo switching in the switch circuit ND01, then are fed into ND 02 for
separation of brightness from color and output as signal Y and C. For N102, no matter whether it’s TV or
AV/SVHS, finally the signals are all fed in the form of Y/C into the input port of VIN1and CIN. Yet the
setup for the software is somewhat different.
The decoding for the text of main channel or CCD/V-CHIP is performed by auxiliary CPU. Video
signal is directly fed to pin 12 of NM5 for decoding. The decoded text or CCD/V-CHIP signal is output in
the form of R, G, B, FB and fed into N102 for character superposing.
Sub-channel:
Signal CCIR601 after being decoded in VPC3230 is directly fed into PW181的G PORT where direct
processing is carried out by PW181. The non-interlace conversion in this channel is performed by the
non-interlace processor inside PW181. Relatively speaking, the efficiency of the internal non-interlace
- 14 -
processor of PW181 is lower than that of PW1230. Therefore when displaying dual picture the main
picture effect is better than that of sub-picture. The adjustment of brightness, contrast, definition and
chroma is performed by N302.
The decoding of CCD/V-CHIP in this channel is specially performed by 21 line decoder N301
Z86229. The decoded information is superposed onto the image in N302 also in the form of R, G, B and
FB.
For VGA and YPRPB, after the selection in N1 YPRPB1 and YPRPB2 are fed together with N402
for channel selection. The selected signal is fed into the ADC part of N403 AD9887 for A/D conversion
so as to produce 24 bit digital RGB signal to be fed into the G PORT of PW181. The line and field
synchronous signal of VGA is directly fed into N403 whereas The line and field synchronous signal of
YPRPB is obtained after synchronous separation of Y signal of SOGIN
in AD9887 (This signal is input to N403 pin 108).
Synchronous switching device is shown in the following figure:
AD9887 is also provided with DVI input port. The DVI input signal is converted into 48 bit digital
RGB signal and sent to G PORT of PW181 for processing. The selection from DVI and VGA/YPRPB is
performed by AD9887.Certain organizations for the oversea sales of this TV series have been equipped
with the capability to decode HDCP. PORTA4 and PORTA5 of PW181 verify the password (cipher key)
through bus line with broadcast equipment. Each TV set has its own independent password, which is
stored in EEPROM.
The mode identification of VGA or YPRPB is performed by PW181. The identification process is :
When selecting channel signal input PW181 presets the synchronous selection of AD9887 so that it
can directly output the required synchronous signal for direct feeding to PW181. The synchronous signal
format is identified inside PW181. By making cross-reference with the format table pre-stored inside a
most similar format is obtained. Then the parameters of this format are called for use in setting up the
parameters for modular conversion so that it is optimized. At the same time the conversion coefficient of
- 15 -
SCALER is confirmed.
3.2. Block diagram of AD9887 is shown below
Finally the video signals of different channels are sent respectively to V PORT and G PORT of main
processing chip PW181 for processing. PW181 has such processing capabilities as “picture out of
picture”, “picture in picture”, “multiple pictures”. So long as the signals come respectively from V PORT
and G PORT, they automatically become “picture out of picture”, “picture in picture”. PW181 has the
function of SCALER, which means it can conduct format conversion for the input signals of different
format to enable it to meet the requirement of the screen for format and finally output the signal in the
form of 24 bit RGB.
The standard of interface for PDP screen is LVDS (low voltage differential signal). So the digital
RGB signal output from PW181 still needs to be converted into LVDS signal by the conversion interface
chip of LVDS - N602 DS90C385 (This chip may vary with the manufacturer of the screen). This
converted signal is in turn fed to the screen for driving purpose. The output of N602 is four pairs of
differential signal and one pair of clock signal. If any pair of signal is abnormal then the image is affected
to be abnormal for example, a certain color may become abnormal. The PWRDOWN signal output from
PW181 is used to control the operation of N602, which works under low electric level.
- 16 -
PW181 is also the main CPU. Its program is stored in the externally connected flash N601. The
software upgrading of RS-232 is actually the upgrading of the stored memory in N601 by PW181. The
interface of menu is also produced by PW181. PW181 can automatically produce self check signal for
trouble shooting.
3．3. Block diagram of PW181 is shown below:
The above is a short account of the signal flow process of the TV series. Please note HS (Horizontal
Synchronous), VS (Vertical Synchronous) and CLK (Clock), PEN (Enable) between individual stages are
invariably the basic reference for the mode identification of lower level chip. Make sure that they are in
normal working condition.
PW181 controls the standby of the complete TV set. The POWER-ON signal output from
PORTB3 of PW181 is used to control the operation of the power supply board. When it is POWER_ON ,
the TV set is switched on with low electric level and is in standby with high electric level. When it’s in
standby the remaining power supply is only 5VSTBY.
The voltage VS required by the operation of screen is also controlled by VS_ON output from logic
board. It is in operation when the electric level is high. Only when the logic board receives correct signal
(clock, synchronous, enable etc.) can VS_ON be correctly output. The operation of PDP screen has very
high demand for the time sequence of power supply. If the time sequence is wrong it might make the
screen unable to work normally.
- 18 -
Distribution of the Circuit Board of Different Screens and their Functions
1、 42SD（Type:S42 SD-YD04，Code No:335-42001-00）
Parts
designation
Function
Power supply
board
Provide power for the operation of complete TV set
Logic board
Convert the LVDS signal from the processing board into the one displayable by
screen
Addressing circuit
Addressing circuit for screen display, directly driving the address electrode on
the screen (Vertical electrode, totally 852X3electrode）
X driving X electrode（horizontal common holding electrode）driving circuit
Y driving
Y electrode（horizontal scanning, holding electrodes, total 480 electrode）driving
circuit
Logic board
Addressing circuit
Y driving
Power supply board
X driving
- 19 -
2、 50HD（Type:S50HW-XD02，Code No.:335-50001-00）
Parts
designation
Function
Power supply
board
Provide power for the operation of complete TV set
Logic board
Convert the LVDS signal from the processing board into the one displayable by
screen
Addressing circuit
Addressing circuit for screen display, directly driving the address electrode on the
screen (Vertical electrode, totally 1366X3electrodes) respectively driving for
upper and lower half fields.
X driving X electrode（horizontal common holding electrode）driving circuit
Y driving
Y electrode（horizontal scanning, holding electrodes, total 768 electrode）driving
circuit
Y driving Power supply board
Logic board
X driving
Addressing
- 20 -
PCB parts and number
Singal processor boards:
Parts number
Parts name
PS-42D8 PH-50D8
Main parts and number
Main board 667-PHID8-01 667-PHSD8-01
N501 PW181-20 (353-01810-00)
N204 PW1230 (353-12300-00)
N403 AD9887-140 (353-98870-30)
N102/N302 VPC3230D (353-32300-80)
N602 DS90C385MTD (353-03850-20)
N601 AM29LV800BT-90E(353-29800-10)
video frequency
processor boards
667-PH42D8-40 667-PH50D8-40
NM5 SDA555XFL (352-05550-20)
NM2 MSP3440G (353-34400-00)
NM9 TDA7053AT (353-70530-70)
video frequency
boards
667-PS42D8-70
TUNER1 JS-6B1/112A2-A2(590-40425-00)
TUNER3 JS-6B1/111C6 (590-40422-00)
Sound
amplification
boards
667-PS42D8-24
NA01/NA02 TPA3001D (353-30010-10)
Transformer board 667-PS42D8-46
Remote parts 301-UPS42D8-09
key-press board
parts
667-PH42D8-05 667-PH50D8-05
power supply filter
parTs
667-PH42D8-51 667-PH50D8-51
Mainboard parts video frequency processor boards
video frequency boards parts
Switch parts video frequency boards
- 21 -
Short circuit the pin 8
(PS-ON) of X709 to the
ground, then check
Diagram of Normal Trouble Shooting
1． “Three no”, i.e., no raster, no picture and not sound:
If power indication lamp is lit
yes no
normal
normal abnormal normal
abnormal
JI
Normal abnormal
normal
Noteower supply for PDP is provided with over current and over voltage protection functions.
If there is over current or over voltage, this protection will function and no output.
Three
check5V-STB
Cutoff the connection
between power board and
signal process ，
check5V-STB
Cutoff the
connection x2
between main
board and video
process. board ，
then determine
Power
board
Check power esp.
D3.3V
N501abno
rmal
Check supply,
crystal oscillation
for N501andN601
Pull out
X709 check
Check
N501and
Check supply for N102、N204、
N302、N403,crystal oscillation and
bus line
Short
circuit in
Power board
- 22 -
2． There is sound but no picture:
yes no
no yes
normal
abnormal
Normal abnormal
Normal abnormal
Note:
For the originally self-powered software, if the operation of PW181 is abnormal, in SDA555X
there may be a state of individually switched-on. In this case very often the phenomenon of the
trouble is there is sound but no image.
Setting up for the self check of the screen:
For 42”SD screen (S42SD-YD04)ush down 2 and 4 and push up 3 of SW2001on the
logic board;
For 50”HD screen (S50HW-XD02)ush down 1 and 4 and push up 2, 3, 5, 6 of SW2001on
the logic board;
Please make sure resume it to the original status when the check is over.
With sound but
If there is
Check if no image for
all other channels 试
N501
and
Change into 4
check
If oscilloscope is
ready，first measure
the wave form of
Pull X604、X709，short circuit pin 8
of X709 to the ground，set logic
board switch to self check signal，see
if the screen appears white when
Check input signal
of N601and power
Screen
N601damag Check N501and the
circuit of output part
电路
- 23 -
3． There is picture but not sound.
If there is output from XA04of sound power amplification board
No
Yes
yes no
yes no
4． A certain channel is abnormal
1) AV no picture
First, use dual picture function to judge if the main or sub picture has problem.
No picture in main channel:
yes no
no yes
no yes
There is
Sound box
Sound power ampl. or other peripheral circuit have
problem. Check power supply，if SHUTDOWN pin
control is normal and if output short circuited or other
Measure if there is signal
in pin 2 of sound power
Measure if the sound input of
the present channel
corresponding to NM2 is
MSP3440 or other
peripheral circuit
Check different levels of circuit
following input audio signal channel
Check if pin 72 of
N102 has signal input
Measure Y and C signal output
from R143~R148and line/field
There is problem from Av socket to
N102channel
Check R209~R213 to see if
PW1230 output is normal
N102 or other
peripheral
N204 PW1230 or
other peripheral
N501 PW181 or
other peripheral
- 24 -
No picture in sub channel:
yes no
yes no
3) No picture in YPRPB or YCRCB
yes no
YCRCB YPRPB
At the same time
normal abnormal
Check to see if pin 72 of
N302 has signal input
Measure Y and C signal output
from R340~R345and line/field
There is problem from Av
socket to N302 channel
问题
N501 PW181 or
other peripheral N302 or other
peripheral
Check if YPRPB/YCRCB1and
YPRPB/YCRCB2 both have no
N1and
interface
Identify if YPRPB
or YCRCB has
Check N302
and
If input VGA
signal is
Check N402 (including
switching voltage
HDTV_SELandC410
Check N403 and
i h
G PORT of N501
and peripheral
- 25 -
4) TV no picture
normal no picture
normal abnormal
normal abnormal
.
normal normal abnormal normal abnormal
normal
Take out dual picture and set the other
picture to TV, to see if this picture is normal.
Input an AV signal to see if AV
channel is normal
Check power
supply for TUNER1,
bus line and video output
Check output signal of N102
（ line/field synchronous,
clk, PEN etc.）
N204 and its
peripheral
circuits
Peripheral circuits of
N501 V PORT have
problem
Input an AV signal to
see if the AV of
dual picture is
If input
VGAsignal is
If voltage of
N702 is
Input circuit of
N102 or
Check if output
signals of N204
（ line/field synch.
CLK ， PEN ） are
Check
N102and its
TUNER
Check in
the
If the connection
between boards is
reliable
- 26 -
4) VGA No Picture
yes no
normal abnormal yes no
normal abnormal
6) DVI no picture
If VGA works normally, it’s enough only to check the connection between socket X401and N403
and the operation status of N403. R414 is the matching resistance for its input. If it has problem the
DVI image would become abnormal.
5． Abnormal picture :
Peculiar color, which may be caused by the following phenomena:
A certain differential wire pair of LVDS（RX0+/-，RX1+/-，RX2+/-，RX3+/-） is abnormal,
which may lead to lack of color ( it’s not a complete loss of color);
Failure with resistor rows R550~R555，which may lead to loss of corresponding color from
the gray degree corresponding to the picture of all channels. Through self signal check by
PW181, the failure is still there.
Failure with resistor rows R419, R421, R425, R427, R431, R432，which may lead to loss of
corresponding color from the gray degree corresponding to the picture of channels
VGA/YPRPB/DVI.
Failure with resistor rows R415, R418, R422, R424, R429, R430，which may lead to loss of
corresponding color from the gray degree corresponding to the picture of channel DVI.
Failure with resistor rows R342, R343, R344, R345 ，which may lead to loss of
corresponding color from the gray degree corresponding to the picture of sub-channels
TV/AV/YCRCB, or lead to abnormal brightness.
If input YPRPB signal is
If the mode of VGA (lower right
corner of screen OSD) identifiable
Measure the input line/field
synch. signal of 81 and 82 of
Check N402
and its
Check N403 and its
peripheral，especially its
output signals (CLK,
line/field synch. and
enable etc.)
Check N403
and its
Input interface
circuit has
If the two TV pictures are
normal
Check input circuit
of GPORT of
N501
- 27 -
Failure with resistor rows R207, R208, R209, R210, R211, R212 or R145, R146, R147,
R148，which may lead to loss of corresponding color from the gray degree corresponding
to the picture of main channels TV/AV, or lead to abnormal brightness.
Bad connection between N203 and N204, which may also lead to abnormal picture
(column bar like) in main channel TV/AV.
Abnormal picture vertically or horizontally (bar like): Abnormal in complete line extending all the
way from up downward on the screen of stand definition TV setr; abnormal vertically on half
screen of high definition TV set. They may be caused by the damage of the address BUFFER
module that directly corresponds to its position, or may be caused by the damage of the
connection wire that directly corresponds to the position of the screen. The horizontal bar like
abnormality is also related to the Y driving circuit that corresponds directly to its position. To
judge these phenomena, It’s possible to check it by setting the screen to the status of self
check as explained above
No brightness in the square block area: Normally it’s caused by the damage of the address
BUFFER module that directly corresponds to its position, or may be caused by the damage of
the connection wire that directly corresponds to the position of the screen. To judge these
phenomena, It’s possible to check it by setting the screen to the state of self check as explained
above
Diagnosis for Plasma Screen of PS42D8
And Maintenance of the Functions of Various Modules on Screen
As shown in the figure below, PDP screen can be divided into power supply board, X driving board, Y
driving board, logic board, logic BUFFER board (E, F, G), Y BUFFER board ( upper and lower), COF
etc.:
Power supply board X driver board
Ydriver board
Logic board
Logic
BUFFER(E)
Logic
BUFFER(F)
Logic
BUFFER(G)
Y BUFFER(up)
Y BUFFER(down)
COF（7 blocks）
- 28 -
* Power supply board: to supply power for the screen, other functional modules on the screen,
our own main board, and video frequency processing board.
* X driving board: to produce and provide driving signal for X electrode according to the time
sequence signal sent from logic board.
* Y driving board: to produce and provide driving signal for Y electrode according to the time
sequence signal sent from logic board.
*Logic board: to process the image signal sent from the main board, to produce addressing
signal and to provide driving signal for X and Y driving boards.
*Logic BUFFER board (E, F): To convert the data signal and control signal sent from the logic
board into the signals required by COF
*Y BUFFER board（Upper，Lower）: to transmit the scanning signal from the Y driving board to
the screen, which is divided into upper and lower parts.
*COF:to convert the signal sent from the logic BUFFER board into the address signal used by
the screen.
II. Trouble diagnosis:
1. The screen is not bright:
a. Check to see if the power supply plug from the power filter board to the power supply board is
well inserted into the socket. If not, plug it in.
b. Check if the fuse on the power supply board is blown up. If yes, replace it for a good one.
c. Remove our main board and the video frequency processing board, ground the pin 4
POWER_ON/OFF of socket CN802 of the power supply board,
and then push the slide switch SW2001 on the logic board to the internal modes (1, 3 up and 2,
4 down) from external modes (1, 2, 4 up and 3down)
Weld drop
- 29 -
Switch the power on and see if the screen is lit. If the screen can give a normal and
completely white field signal, then the problem lies in our main board or video frequency
processing board, which will be dealt with separately.
d. If the screen is not lit, then first replace the power supply board to see if the problem is
solved.
e. If the problem remains after the power supply board is replaced, then the problem lies in the
screen. Replace the entire screen for treatment.
2. There appears on the screen a line or several unlit lines.
Check if the socket between Y driving board and Y BUFFER is plugged well. If not, plug it well. If
yes then replace Y BUFFER (upper, lower) in respect to the upper , lower part of the dark line on
the screen.
3. There appear on the screen one or several horizontal lines that are much brighter than the
remaining horizontal lines at the edge:
Check if the socket between Y driving board and Y BUFFER is plugged well. If not, plug it well. If
yes then replace Y BUFFER (upper, lower) in respect to the upper , lower part of the dark line on
the screen.
4. There appear on the screen one vertical unlit line or a vertical entirely unlit block
SW2001
- 30 -
a. If it’s one vertical unlit line, then COF has problem.
b. If it’s a vertical entirely unlit block, then first check if the connection socket between COF and
logic BUFFER has problem. If not, check if the connection socket between the logic BUFFER
and the logic board is normal. If yes, replace the logic BUFFER. Finally, if the problem still
remains when the replacement is over, then replace the logic board.
5. There appears on the screen a mono color signal and one or several vertical bright lines of other
colors:
a. If it’s a vertical bright line of other colors, then the problem lies with COF or the screen.
b. If it’s an entire vertical block of other colors, then first check to see if the connection socket
between COF and logice BUFFER has problem. If no problem, check if the connection
socket between the logic BUFFER and the logic board is normal. If it’s normal, then replace
the logic BUFFER. If the problem still remains after the replacement, then replace the logic
board. Finally if the problem is still there, then the problem lies with COF.
6. There appear on the screen abnormal bright spots or blocks that are different from what’s
described above:
a. Check if the connection socket between COF and logic BUFFER board has been well
plugged.
b. Replace the logic BUFFER board. If it’s not solved then replace logic board. If the problem
still remains, then it’s the problem with COF.
---------------------------------
闲来无事，整理一下，不会怪罪我吧
厦华PS42D8中文维修手册
(10.75 KB)
---------------------------------
:P :P :P
厦华PS42D8中文维修手册.part1.part1
:P :P :P
---------------------------------
:lol
厦华PS42D8中文维修手册.part1.part2
(1.39 MB)
厦华PS42D8中文维修手册.part1.part3
(1.39 MB)
---------------------------------
:lol :lol :lol
厦华PS42D8中文维修手册.part1.part4
(1.39 MB)
---------------------------------
:lol :lol :lol :lol :lol :lol :lol :lol
厦华PS42D8中文维修手册.part1.part5
(1.39 MB)
厦华PS42D8中文维修手册.part1.part6
(68.95 KB)
阅读权限: 30
---------------------------------
阅读权限: 30 ???????
---------------------------------
为什么最后一个在设权限？ :Q :Q :Q
---------------------------------
国内的维修手册，真是LOW。讲解得一点都不清楚。没有图纸，没有PCB图。没有组装结构图。
楼主好资料
---------------------------------
没有阅读权限: 30 怎么办
游客，您好 
