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初步判断面板上某按键漏电,但依次拆除面板上所有按键逐个检查,未发现异常。不装按 (12/14/2005 12:53:00) [查看全文] 屡烧电源开关管Q823 (12/14/2005 12:53:00) [查看全文] 观察图像发现L (12/14/2005 12:53:00) [查看全文] 首先判断场电路可能接触不良。观察IC45 (12/14/2005 12:53:00) [查看全文] 经查保险丝完好,但电源的各路输出电压均为待机状态值, (12/14/2005 12:53:00) [查看全文] 估计该机保护电路动作。因该机无图纸,查有关资料,该机 (12/14/2005 11:44:00) [查看全文] 查主电源输出电压为135V (12/14/2005 11:44:00) [查看全文] 测 (12/14/2005 11:44:00) [查看全文] 按开机键,待命红灯熄灭后数秒钟复亮,在待命灯熄灭的瞬间有加上高压时特有的“沙”声。测 (12/14/2005 11:44:00) [查看全文] 该故障的典型特征是待机指示灯闪烁,似乎是在显示某种自检信号。估计其原因有:( (12/14/2005 11:44:00) [查看全文] 该机开机瞬间待机指示灯闪烁一下后常亮,说明开关电源工作基本正常,同时说明 (12/14/2005 11:44:00) [查看全文] 由于有彩色画面,说明注入IC201 (12/14/2005 11:44:00) [查看全文] 查行管、电源管2SD850 (12/14/2005 11:44:00) [查看全文] 测+B (12/14/2005 11:44:00) [查看全文] 该机最初的故障现象是开机三无,经更换行输出变压器后,图像及伴音恢复正常,但画面 (12/14/2005 11:44:00) [查看全文] 在正常情况下,CPU (12/14/2005 11:10:00) [查看全文] 测三只视放管 (12/14/2005 11:10:00) [查看全文] 观察显像管灯丝亮度正常,测各视放管c (12/14/2005 11:10:00) [查看全文] 该机采用东芝CTS130 (12/14/2005 11:10:00) [查看全文] 故障出现时测开关电源输出的112V (12/14/2005 11:10:00) [查看全文] 由故障现象分析光栅收缩可能与电源有关,而逃台时该电压下降。查开关电源主输出电压(原图标为115V (12/14/2005 11:10:00) [查看全文] 该机CPU (12/14/2005 10:58:00) [查看全文] 根据该故障的特殊性,先查场幅缩小故障。测场输出块IC501 (12/14/2005 10:58:00) [查看全文] 根据TA (12/14/2005 10:58:00) [查看全文] 这种现象,表明热机时显像管红枪电子束电流过大。其常见原因有:(1 (12/14/2005 10:58:00) [查看全文] 测开关电源+B (12/14/2005 10:58:00) [查看全文] 检查开关电源和CPU (12/14/2005 10:58:00) [查看全文] 经检查,是色带通滤波器T803 (12/14/2005 10:58:00) [查看全文] 直观检查,发现R314 (12/14/2005 10:58:00) [查看全文] 测+300V (12/14/2005 10:58:00) [查看全文] 测IC301 (12/14/2005 10:58:00) [查看全文] 测红色视放管V (12/14/2005 10:58:00) [查看全文] 测TA7698 (12/14/2005 09:52:00) [查看全文] 调整行频电位器R626 (12/14/2005 09:52:00) [查看全文] 测量CPUM50436-560SP (12/14/2005 09:52:00) [查看全文] |
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