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故障现象:接通电源开关,电源指示灯不亮,电子寻像器上无光栅,按“出盒”键带仓弹不出。分析与检修:由上述现象分析,初步判断故障出在开关电源电路中。拆开机器右边机壳,在主印制板(VEP03582A)右下方找到开关电源电路,用500型万用表检查脉冲控制放大集成电路 IC1002(UN102)②脚和(15)脚上 UNREG 12V 电压正常,接通电源开关,检查IC1002③、⑤、⑦、⑨、(11)脚和(13)脚均无电压输出,弹出电池,用万用表检查 IC1002各脚在路对地正反向电阻,发现③、⑤脚红表笔测为1.3kΩ,黑表笔测为∞(正常值应分别为1.2kΩ和5kΩ),见表1所示。说明
Symptom: Turn on the power switch, the power light does not shine, no electronic grating on the viewfinder, press the “out of the box” button with a warehouse can not be bombed. Analysis and Maintenance: From the above analysis of the phenomenon, the initial judge fault in the switching power supply circuit. Disassemble the right side of the machine chassis, the main PCB (VEP03582A) lower right to find the switching power supply circuit, with a 500 multimeter to check the pulse control amplifier IC1002 (UN102) ② feet and (15) feet UNREG 12V voltage normal Check the IC1002 ③, ⑤, ⑦, ⑨, (11) feet and (13) feet are no voltage output, pop-up batteries, check the IC1002 feet with a multimeter in the road to the positive and negative resistance, found ③, ⑤ pin Red test pen measured 1.3kΩ, black test pen measured ∞ (normal value should be 1.2kΩ and 5kΩ, respectively), as shown in Table 1. Description