MCSTP8 16磁带机控制器是美国 MCS公司生产的适用于微型计算机和符合 Pertec工业标准的 9轨开盘磁带机 M4、Qaulstar、STC2 92 5等相连接的高性能接口板 ,它的读写位数是 8位。由于厂家没有提供必要的硬件维护手册和电路原理图 ,当该设备发生故障时 ,故障定位十分困难。文中通过对该设备发生的读写故障的分析 ,给出用万用表追踪对比法和用写全“0”、全“1”码检测故障的办法 ,成功地定位了该设备的故障组件。文中给出的两种方法 ,对硬件维护人员的设备维护工作具有重要的参考价值 MCSTP8 16 tape drive controller is produced by the United States MCS Microcomputer and meet Pertec’s industry standard 9-track open tape drive M4, Qaulstar, STC2 92 5 connected high-performance interface board, which read and write digits 8 bits. Since manufacturers did not provide the necessary hardware maintenance manuals and circuit schematics, fault location was difficult when the equipment failed. Through the analysis of read and write failures of the device, this paper gives a method to detect the fault by using multimeter to track the contrast method and write all “0”, all “1” codes, and successfully locate the fault components of the device. The two methods presented in this paper have important reference value for the equipment maintenance of hardware maintenance personnel