故障现象 东成HA838(IV)P/T电话机不能拨号,通话时,送受话音量均过小。 分析与检修 一般电话机电路均由振铃系统、极性转换系统、拨号系统和通话系统组成。新型电话机还有免提系统、液晶显示系统以及无绳电话机的高频电路等系统。通常,人们检修电话机的方法是头疼医头,脚疼医脚,而实际上,各部分电路是相互关连的,如通话电路中某元器件不正常却表现为拨号系统的拨号 Symptoms East into HA838 (IV) P / T phone can not dial, call, send and receive volume are too small. Analysis and maintenance of the general telephone circuit by the ring system, polarity conversion system, dial-up system and call system. The new phone also has hands-free system, liquid crystal display systems and high-frequency circuits and other wireless telephone systems. In general, people overhaul the phone is a headache, pain feet, but in fact, the various parts of the circuit are interrelated, such as the call circuit is not a normal part of the dial-up system for dial-up