Toshiba SATELLITE U200 manual Procedure 2 Debugging Port Check Boot Mode

2 Troubleshooting Procedures 2.4 System Board Troubleshooting

Procedure 2 Debugging Port Check (Boot Mode)

Check the D port status by a debug port test. The tool for debug port test is shown below.

Figure 2-1 A set of tool for debug port test

The test procedures are follows:

1.Connect the debug port test cable to the connector CN3490 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 test results.

4.Boot the computer in MS-DOS mode.

5.Execute GETDPORT.COM in the text menu in CPU REAL mode. (Insert the FD for starting D port into FDD and input “FD starting drive:>dport”.)

The D port status is displayed in the following form;

6.When the D port status is FFFFh (normal status), go to Procedure 4.

When the D port status falls into any status in Table 2-4, execute Check 1.

2-22 [CONFIDENTIAL] PORTÉGÉ M500 Maintenance Manual (960-559)