论文部分内容阅读
例1 HW—33 ⅡP/TD型台机有响铃,但手机不能拨号,也不能进行对讲。分析与维修:外来电话的时候手机有响铃,说明手机的接收单元功能是基本正常的;按下手机的“CALL”键后有调频收音机也能收到很强的信号,说明手机的发射单元功能也基本完好,判断故障范围存在于台机的高频放大,中放解调及话音耦合部分。对于这种台机无接收的故障,一般先从调频中放集成电路IC_1入手,见图1所示。打开手机
Example 1 HW-33 ⅡP / TD type machine has a ring, but the phone can not dial, nor can intercom. Analysis and Maintenance: When the phone is ringing, it indicates that the receiving unit of the phone is basically normal. Pressing the “CALL” key of the phone can also receive a strong signal indicating that the transmitting unit of the phone Function is basically intact, to determine the scope of the fault exists in the high-frequency amplification of the machine, in the demodulation and voice coupling part. For this Taiwan machine without receiving the fault, the general first put the IC from the FM IC1 start, shown in Figure 1. Open the phone