Toshiba T2100 Series Maintenance Manual page 37

Procedure 3 Printer Port LED Check on Resume Mode
The printer port LED displays the IRT status and test status by turning lights on and off as an
eight-digit binary value for resume mode.
To use the printer port LED follow these steps:
1. Turn on the T2100/T2105 Series computer's power, then set it to resume mode.
2. Turn the computer off.
3. Plug the printer port LED into the computer's parallel port.
4. Turn the computer on.
5. Read the LED status from left to right as you face the back of the computer.
6. Convert the status from binary to hexadecimal notation.
7. If the final LED status is FFh (normal status), go to Procedure 4.
8. If the final LED status matches any of the test status values in Table 2-2, go to
Procedure 5.
Table 2-2 Printer port LED resume mode error status
Error status
F1H RAM BIOS error
F2H The system has optional ROM, or optional card (CGA, MDA).
F5H Main memory checksum error
F6H Video RAM checksum error
F7H Extended memory checksum error
T2100 Series
Meaning of status
2-15