Epson 1170 - Manual (Page 113)

Options
When you use two tractor units in combination, continuous
paper does not feed properly.
l
The paper feed is crooked or paper jams.
Make sure that the sprocket units on both tractors are
aligned.
When you use an optional interface, the printer does not operate
properly.
l
The printer does not print or the printout is not what you
expected.
You may be trying to use an interface or interface cable
with the wrong specifications. Check the specifications to
make sure you can use the interface with this printer.
The computer and printer interface settings may not match.
Make sure the settings on the computer and printer match.
6-12 Troubleshooting