Kenwood NXR-700H Service Manual

NXR-700H95Procedure for Traceability of BGA Package andHow to Replace Control UnitThis clause is procedure when you replace Control uniton you repair. Implement traceability of BGA package in or-der to make sure BGA failure in prior to replace Control Unit.You choose appropriate procedure accordingly.1. Traceability of BGA Package ICs in Control UnitThe control unit (X53-414) of NXR-700H series have BGApackage ICs. BGA package IC is difficult to trace whether itbe broken. So, control unit is difficult to confirm whetherit has a problem. This document shows a simple methodby PC to confirm the control unit has problem. The twomethods for traceability in BGA packages IC are provided asbelow.1-1. Simplifi ed traceabilitya) Open the top cover of control unit.b) Slide the tab on DIP_SW4 (Ref No. S700) to the ON posi-tion. (See Fig 1.)c) Connect a cross-wired RS-232C cable to COM port on thefront panel of NXR-700H. Plug the other end of the cableto PC. (See Fig 2.)d) Run a communication software, example a Hyper Termi-nal in Windows, and set the following parameters.e) COM port: COM port of NXR-700H used in step c.TROUBLE SHOOTING / 故障排除BGA 封装的追溯步骤和控制单元的更换方法本节介绍修理时更换控制单元的步骤。实行 B G A 封装追溯的目的是在更换控制单元之前确认 B G A 故障。您可以选择相应的适当方法。1. 控制单元中 BGA 封装 IC 的追溯方法NXR-700H 系列的控制单元 (X53-414) 含有 BGA 封装 IC。追溯 BGA 封装 IC 是否已损坏比较困难，因此，控制单元难以确认它是否有问题。本文介绍通过 P C 确认控制单元是否存在问题的简单方法。BGA 封装 IC 的两种追溯方法说明如下。1-1. 简单追溯a) 打开控制单元的顶盖。b) 将 DIP_SW4(Ref No.S700) 的突起滑到 ON 位置。( 参见图 1)c) 将 RS-232C 交叉电缆连接到 NXR-700H 前面板的 COM 端口。将交叉电缆的另一端插到 PC 上。( 参见图 2)d) 运行通信软件，例如 Windows 中的 Hyper Terminal，然后设置以下参数。e) COM 端口 : 步骤 c. 中使用的 NXR-700H 的 COM 端口。Control blockMain MPU: IC703RF controlMPU: IC34Modem controlMPU: IC325TXD,RXD,RTS,CTSCD,RD,SD,DTR,DSR,RTS,CTS,RICOM (DSUB9)