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TCL HW868(21)P/TSD(LCD)无绳电话机主机电路主要由微处理器(CPU)U4(86821B)、接收/可编程锁相环控制电路及语言压缩扩展电路U1(TB8528B)、发射电路(V3、V2、V4等组成)、有绳手柄、免提电路A1(86821A)等部分组成。下面介绍主机电路几例常见故障的检修方法。 故障现象 不能设置联机安全密码。 分析检修 引起该故障的可能原因有:R/CODE密码设置键导电橡胶老化或键盘漏电;主机外接电源系
The host circuit of TCL HW868 (21) P / TSD (LCD) cordless telephone is mainly composed of microprocessor U4 (86821B), receive / programmable phase locked loop control circuit and language compression expansion circuit U1 (TB8528B), transmitting circuit (V3, V2, V4 and other components), rope handle, hands-free circuit A1 (86821A) and other components. Here are a few common host circuit troubleshooting methods. Symptom Can not set the online security password. Analysis and maintenance of the cause of the failure may be due to: R / CODE password setting button conductive rubber aging or keyboard leakage; host external power supply system