Toshiba libretto U100 Maintenance Manual page 64

2 Troubleshooting Procedures
Procedure 2 Debugging Port Check
Check the D port status by a debug port test. The tool for debug port test is shown below.
The test procedures are follows;
1. Connect the debug test cable to the connector CN3400 of the System board. For
disassembling to connect the test cable, refer to Chapter 4.
2. Connect the debug port test cable and RS-232C cross-cable to the test board.
3. Connect the RS-232C cross-cable to the PC that displays the results.
4. Boot the computer in MS-DOS mode.
2-20 [CONFIDENTIAL]
Figure 2-2 A set of tool for debug port test
2.4 System Board Troubleshooting
libretto U100 Maintenance Manual (960-520)