Toshiba PORTEGE M400 Maintenance Manual page 161

2.4 System board Troubleshooting
Procedure 2 Debug Port (D port) Check on Boot Mode
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 port test cable to the connector CN3400 of the System board. For
disassembling the PC 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 displaying the test results.
4. Boot the computer in MS-DOS mode.
PORTEGE M400 Maintenance Manual (960-541)
Figure 2-2 A set of tool for debug port test
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2 Troubleshooting
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