Toshiba Portege R500 Maintenance Manual - Page 64

2 Troubleshooting Procedures 2.4 System Board Troubleshooting Procedure 2 Debugging Port Check (Boot Mode) Check the D port status by a serial port test. The tool for serial port test is shown below. Figure 2-2 Debug port (Boot mode) error status 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 compute1r in 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 FFFF (normal status), go to Procedure 4. When the D port status falls into any other status than FFFF, go to Procedure 3. 2-18 [CONFIDENTIAL] PORTEGE R500 Maintenance Manual (960-634)