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笔者接修一台乐华 R—2138型彩电,故障现象为水平一条亮线。按经验分析,水平一条亮线,由下列因素而产生:场输出块无26V 供电电压;场输出集成块TDA3653B 损坏;场振荡电路停振;场偏转线圈短路或断路;直流反馈电路元件不良等。,结果笔者在检修中走了很大弯路,并且闹出了一大笑话。借贵刊告诫同行避免造成不必要的损失。检修纪实:打开机盖仔细观察,发现该机已修理过,用万用表测量 TDA3653B⑨脚无26V 电压,将万用表置电阻档测量 R408(0.68Ω)电阻烧断,换 R408,将 TDA3653B⑨脚断开,开机测26V 电压正常。是否因 R408烧断造成场不工作?于是焊开⑨脚,开机 R408又被烧断,屡烧 R408证明26V 负载有短路现象。将TDA3653B 集成块焊下发现④、⑤脚之间烧黑,故确定
I pick up a Leroy R-2138-type TV, the level of a fault line. According to empirical analysis, the level of a bright line, resulting from the following factors: field output block without 26V supply voltage; field output manifold TDA3653B damage; field oscillation circuit stop vibration; field deflection coil short circuit or open circuit; DC feedback circuit components such as poor. , The result I took a great detour in the overhaul, and downtown a big joke. Use your magazine to warn your colleague to avoid unnecessary losses. Maintenance record: Open the lid and carefully observed and found that the aircraft has been repaired, measured with a multimeter TDA3653B ⑨ feet without 26V voltage, the meter set resistance range measurement R408 (0.68Ω) resistance blow, change R408, the TDA3653B⑨ feet open, boot Measuring 26V voltage is normal. Is it because the R408 burn caused field does not work? So open the ⑨ foot, boot R408 has been blown, burning R408 prove that the 26V load short circuit. The TDA3653B integrated block welding found ④, ⑤ black burn between the feet, it is OK