Sharp PC-A280 Manual page 81

Confirm the external floppy disk drive unit is connected correctly.
Confirm the application program is compliant with the RS-232C standard
interface.
Confirm the COM1 port is not disabled using the following procedure.
1. In the System Properties dialog box, select Device Manager.
2. Double-click Ports(COM&LPT); then, Communications Port (COM1).
3. Make sure the item Disable in this hardware profile is unchecked.
Confirm the COM 1 port is not used by another applications.
Confirm the item Serial Port is set appropriately in the Advanced menu of the
Setup Utility.
Trouble with Communication
Question: Why can't I communicate through the built-in IR port?
Confirm the IR port of your computer is lined up with the IR port of the other
device. These ports should be no more than 20 inches (50 cm) apart without any
obstacles.
Confirm that IR communication is not turned off in the Sharp IR dialog box.
Confirm the item Mode of IR Port is set to IrDA in the Advanced menu of the
Setup Utility.
Turn off power management in the Windows.
Do not use the IR port under intense fluorescent light or near cellular phones.
Question: Why can't I communicate through the built-in modem?
(The built-in modem may not be available in some countries)
Confirm the telephone line is properly connected to the modem jack.
Confirm the dial settings of Windows 98 or communication software are matched
with the telephone line (Example: To access an outside line, first dial "7" for
local, "1" for long distance).
Confirm the network configuration is appropriate.
Confirm the user name or password is correct.
Confirm the COM port in the communication software is set appropriately.
Turn off the power management in the Windows.
T-6 Troubleshooting