Epson LQ-2550 Technical Manual page 227

7. Incorrect printing in ON LINE mode
I
Perform
the self test.
Check the interfoce
cable between the
printer and host
computer as follows:
Are the signal
connections correct? *1
cable connected firmly?
the fault corrected?
N
RS-232C Serial . . Refer to Section 1.3.2.
I
Refer to other
troubleshooting items.
Check the settings
of the interface
between the printer
and host computer.
5-15
I
Change the settings.
I