摩托罗拉cd928是双频GSM型手机,其接收电路由天线开关、滤波器、高频放大器、高频滤波器、压控振荡器、混频器、中频放大器、中频滤波器、中频频率合成器及数字信号处理器等组成,其中任一部件工作不良均会导致手机不能正常工作。现将该机接收电路几例常见故障检修方法介绍如下,供同行参考。 故障现象 开机后不能进行正常通话,也无网号和信号强度显示。 分析检修 根据故障现象分析,引起该故障的主要 Motorola cd928 is a dual-band GSM mobile phone, the receiving circuit consists of antenna switches, filters, high frequency amplifiers, high frequency filters, voltage controlled oscillators, mixers, IF amplifiers, IF filters, IF synthesizers and digital Signal processor and other components, any part of the poor work will lead to the phone can not work properly. Now the aircraft received several common circuit troubleshooting methods introduced below, for peer reference. Symptom After the boot can not be normal calls, there is no network and signal strength display. Analysis and repair According to the failure phenomenon analysis, the main cause of the failure