Epson Expression 1680 Reference Manual page 109

Make sure the computer has enough memory for your
software. If the computer does not have enough memory
available, see your software and computer documentation for
information on adding more memory.
The scanner cannot be selected or is listed as unavailable
in Windows.
Turn off the scanner and PC, and check that they are
connected properly.
Make sure that a scanner supported by EPSON Scan Server
and EPSON TWAIN Pro Network is connected to the scanner
server PC.
For Windows Millennium Edition, 98, and 2000, make sure
EPSON TWAIN Pro is installed on the scanner server PC (the
PC which is connected to the EPSON scanner).
If you want to scan using the scanner server PC, make sure
EPSON TWAIN Pro Network is installed on the PC.
When connected using the SCSI interface, change the
scanner's SCSI ID number to one that is not being used by any
other SCSI device.
Note for Windows 98 users:
Depending on your Windows 98 version, you may have to uninstall
the scanner from your system before changing the SCSI ID number.
For instructions, see "When changing the ID number or replacing
the SCSI board in Windows 98" in Chapter 2 of the online Setup
Guide.
Check the SCSI connection sequence and make sure the
scanner's terminator switch is set correctly. The terminator
switch should be set to ON when the scanner is connected
directly to the computer, or when it is the last device in a daisy
chain. For more information on setting the terminator switch,
see your online Setup Guide.
5-8
Maintenance and Troubleshooting