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一台由 AC100V 电源供电的 TH3070针式打印机,由于操作者误将电源插头插入 AC220V 电源,开机后机内“啪”的一声作响,后再经降压变压器(220V/100V)接入,开机,指示灯不亮,风扇电机不旋转,字车不复位,全部功能无。一、初步检查与修理:总电源开关接点烧蚀,电源进线2A 熔丝熔断,开关电源调整管 C2749各极击穿短路,该管发射极0.22Ω接地电阴开路,选彩电电源调整管 BU208A(1000V,5A,100W)外设散热器接入,将其发射极直接接地。送100V 交流电压,开关电源
A TH3070 stylus printer powered by AC100V power supply, because the operator mistakenly plugged the power plug into the AC220V power supply, the sound inside the machine was snapped and then connected to the step-down transformer (220V / 100V) , Boot, light does not shine, the fan motor does not rotate, the word car is not reset, all features no. First, the initial inspection and repair: the main power switch contact ablation, the power into the line 2A fuse blown, switch power supply regulation C2749 each pole breakdown short-circuit, the tube emitter 0.22Ω grounded open circuit, select the color TV power regulator tube BU208A (1000V, 5A, 100W) peripheral heat sink access, the emitter directly to ground. Send 100V AC voltage, switching power supply