论文部分内容阅读
故障现象 一台由83P机心组装的三洋CTP4940-00型18英寸彩色电视机,开机后,机内传出无规律的“啪啪”响声,且屏幕上的图像也随着响声呈水平横条状,响声严重时光栅会瞬间消失,响声不出现时机器正常工作。 分析与检修 通电开机,首先直观检查较易出现打火现象的开关电源及行输出变压器部分,发现“啪啪”响声确是由行输出变压器T480磁心紧固铜丝与屏蔽板间放电打火引起的,且在打火放电较轻时,图像同步地也随之出现横条状,打火严重时,整机会瞬时间关机。 为了排除此打火现象,拆下行输出变压器,先将打火部位用无水酒精清洗烤干,然后在行变打火处的外壳上用环氧树脂薄薄地浇上两层(先浇一层,待其干透后再浇一层),待环氧树脂干透后,将行变装回原处,并开机试验,该处放
Symptom A Sanyo CTP4940-00 18-inch color TV assembled by a 83P movement was launched. After powering on, a random “pop” noise was heard inside the machine, and the image on the screen was horizontal with the sound Like, the grating will disappear when the sound is serious, the machine does not work normally when the noise does not appear. Analysis and maintenance Power on the boot, the first visual inspection is more prone to spark phenomenon switching power supply and the line output transformer part and found that the “pop” sound is indeed the output transformer T480 core tightening copper wire between the shielding plate discharge sparks caused , And lighter in the spark discharge, the image also appears along with the bar sync, serious fire, the whole instantaneous shutdown. In order to eliminate this phenomenon of fire, remove the line output transformer, the first part of the fire with alcohol cleaning dry, and then change the fire in the shell with a thin layer of epoxy resin poured (first layer , To be dry after pouring a layer), until the epoxy resin dry, the line will be changed back to the original place, and boot test, the place to put