Sharp PC-A820 Manual page 88

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 30 inches (1meter) apart without any
obstacles.
Confirm that IR communication is turned on in the Infrared Monitor window.
Confirm the item IrDA port is set correctly in the Advanced menu of the setup
utility.
Turn off power management and screen savers.
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 telephone socket.
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 and screen savers.
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