Epson SQ-2550 User Manual page 224

Problem
Using an optional
interface, the
printer does not
operate properly.
The printer does not
print or the printout
is not what you
expected.
7-26 Troubleshooting
Solution
The interface may not be installed
correctly. Turn off the printer and check
that the interface board is correctly
inserted into the connector on the main
board.
You may be using the wrong interface.
Check the specifications to make sure
that you can use the interface with this
printer.
The DIP switches or jumpers on the
interface board may be set wrong. See
the interface manual for the correct
settings. Before changing the settings,
however, make sure the printer is turned
off and the power cable is unplugged.
The interface may not be configured
correctly to operate with the computer.
See your computer manual for the
correct settings.
The computer and interface settings may
not match. Make sure to match the
settings for each condition.