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故障现象:电源不启动。分析与检修:用万用表测电源开关管Q_(313)(2SD1710)集电极电压320V正常,Q_(700)无5V输出,致使微处理器IC701不工作,测T_(371)次级无交流电压输出,取下T_(371)初级开路,换T_(371)后,5V输出正常,Q_(751)、Q_(701)也工作正常,接通主电源开关,电源指示灯发光,按下电源副开关SW_(715)时,电源指示灯灭,这表明微处理器工作正常,电源不启动故障可能在电源本身不振荡,使+B无输出。测Q_(313)的基极电压,在按下主电源
Symptom: power does not start. Analysis and Overhaul: Use a multimeter to measure the power switch Q_ (313) (2SD1710) collector voltage 320V normal, Q_ (700) no 5V output, resulting in the microprocessor IC701 does not work, measured T_ (371) secondary AC voltage output , Remove T_ (371) primary open circuit, change T_ (371), 5V output is normal, Q_ (751), Q_ (701) is also working properly, turn on the main power switch, power indicator light, press the power sub switch SW_ (715), the power indicator is off, indicating that the microprocessor is working properly, the power does not start the fault may not oscillate in the power itself, so + B no output. Measure the base voltage of Q_ (313) when the main power is pressed