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本文针对金星 C4918遥控彩电的几例不常见故障,介绍一些分析检修的方法,供读者参考。图1是该机电源电路图。故障现象1:开机无光无声,指示灯亮。维修分析:开机指示灯亮,可证明遥控板电源正常,首先检查主板电源保险管 BX_1,没有发现烧毁现象,进一步检测整流全桥 ZD_(1～4)a、b端,发现无整流电压输出,怀疑线圈L_(401)有开路现象,经测试L_(401)1、3端,发现有 220V电压输出,排除了L_(401)有开路故障的可能。当测试整流全桥交流输入端时,发现无交流电压,故怀疑主电源控制继电器RLY401中的K_2没有闭合,经检测 RLY401控制线圈 1、2端对地电压大致相
This article for Venus C4918 remote color TV several common failures, introduced some methods of analysis and maintenance for your reference. Figure 1 is the machine power circuit diagram. Symptom 1: boot silent, the indicator light. Maintenance Analysis: boot indicator light, remote control board can prove normal power supply, first check the motherboard power fuse BX_1, did not find the phenomenon of burnout, and further detection of rectified full bridge ZD_ (1 ~ 4) a, b terminal and found no rectified voltage output, The coil L_ (401) has an open circuit. After testing L_ (401) and 1 and 3 terminals, 220V voltage output was found, which ruled out the possibility of L_ (401) being open. When the test rectifier full-bridge AC input, found no AC voltage, it is suspected that the main power control relay RLY401 K_2 is not closed, the detected RLY401 control coil 1, 2 end to ground voltage is approximately