Toshiba Portege M100 Maintenance Manual - Page 63

2.4 System Board Troubleshooting 2 Troubleshooting Procedures To use the printer port LED, follow the steps below: 1. Plug the printer port LED into the parallel port of the Advanced Port Replicator. 2. Turn on the computer. 3. Read the LED status from left to right as you are facing the back of the computer. 4. Convert the status from binary to hexadecimal notation. 5. If the final LED status is FFh (normal status), go to Procedure 3. 6. If the final LED status matches any of the test status values in Table 2-3, perform Check 1. NOTE: If an error condition is detected by the IRT test, the printer port LED displays an error code after the IRT test ends. For example, when the printer port LED displays 13h and halts, It indicates that the system memory test has already completed and an error has been detected during the expansion memory test. Table 2-4 Printer port LED boot mode status (1/5) LED Status FFh B0h Test item Start Flash ROM check B1h EC/KBC rewrite check B2h BIOS rewrite System BIOS rewrite transition to IRT BIOS rewrite process B5h Message Register initialization for boot block PIT ch.0 initialization BIOS rewrite flag initialization Transition to protected mode Boot block checksum Checksum check except boot block KBC initialization BIOS rewrite request check System BIOS rewrite transition to IRT BIOS rewrite register initialization PIT channel 1 initialization PIT, DMAC,PIC initialization Memory type check Cache bus, L2 initialization, configuration Enabling L1 cache Memory clear Protecting flash ROM area cache PORTEGE M100 Maintenance Manual (960-452) 2-21