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徒弟:有绳免提不能送话或受话,应如何检修? 师傅:若有绳免提只是不能送话,则重点检查MIC送话器上有无1.5V左右的工作电压。若无,应检查V_B供电及R67电阻有无不良、C26有无漏电;若电压正常,可用“碰触干扰法”按原理中所讲的送话信号传输路径判断故障部位。检修中也有因U4(MC4066)电子开关芯片不良引起的不能送话能受话,或不能受话能送话故障,而U2损坏比较少见。若有绳免提只是不能受话,则重点检查R57,免提音量电位器有无接触不
Apprentice: cordless hands-free can not send or receive, how to overhaul? Master: If the rope hands-free just can not send words, then focus on the microphone to check whether there is about 1.5V operating voltage. If not, should check the V_B power supply and R67 resistance is not bad, C26 with or without leakage; if the voltage is normal, available “touch interference method” according to the principle of sending signal transmission path to determine the fault location. Overhaul also due to U4 (MC4066) electronic switch chip caused by the poor can not send words, or can not be called to send fault, and U2 damage is relatively rare. If the rope hands-free just can not accept the words, then check the key R57, hands-free volume potentiometer with or without contact