请问我的SEEK(10)2Bh怎莫老返回失败啊?

请问我的SEEK(10)2Bh怎莫老返回失败啊?填充代码:
srbExecSCSICmd.SRB_Cmd = SC_EXEC_SCSI_CMD;
srbExecSCSICmd.SRB_HaId = HA;
srbExecSCSICmd.SRB_Target = ID;
srbExecSCSICmd.SRB_Lun = LN;
srbExecSCSICmd.SRB_Flags = SRB_DIR_IN | SRB_EVENT_NOTIFY;
srbExecSCSICmd.SRB_BufLen = 8;
srbExecSCSICmd.SRB_BufPointer = buf;
srbExecSCSICmd.SRB_SenseLen = SENSE_LEN; //SENSE_LEN系统定义
srbExecSCSICmd.SRB_CDBLen = 10;
srbExecSCSICmd.CDBByte[0] = SEEK10;
srbExecSCSICmd.CDBByte[1] = LN & 0xE0; //置LUN
srbExecSCSICmd.CDBByte[2] = HIBYTE(HIWORD(CDB_LBN));
srbExecSCSICmd.CDBByte[3] = LOBYTE(HIWORD(CDB_LBN));
srbExecSCSICmd.CDBByte[4] = HIBYTE(LOWORD(CDB_LBN));
srbExecSCSICmd.CDBByte[5] = LOBYTE(LOWORD(CDB_LBN));