CF-28 - Panasonic PC Service Manual (repair manual). Page 24

Make sure that connecting cables, connectors and AC adapter are not loose or disconnected prior to 
testing.

1

Data does not print from
the printer.

1-1

Does the printer pass its
self-printing test?

YES  Main PCB 

IC47

NO

Printer

2-2

Is the Parallel Port (Data
Direction) setting correct?

YES  Main PCB 

IC47

NO

Improper setting

2

Data prints out incorrectly.

2-1

Does the printer pass its
self-printing test?

3

The unit hangs after
outputting data from the
printer.

3-1

Replace the Main PCB.
Does operation return to
normal?

YES

Go to No. 2-2

NO

Printer

YES  Main PCB 

IC47

NO

Printer

4

Print area is out of line.

4-1

Does the printer pass its
self-printing test?

YES  Main PCB 

IC47

NO

Printer

5

Data is printed all on one
line.
(Carriage return does not
work.)

4-2

Does the printer pass its
self-printing test?

YES  Main PCB 

IC47

NO

Printer

Make sure that connecting cables, connectors and AC adapter are not loose or disconnected prior to 
testing.

1

Data cannot be sent or
received.

1-1

Is the Infrared Communica-
tion Port enabled in Setup?

YES

Go to No. 1-2

NO

Improper setting

2

Transmitted data becomes
corrupted.

2-1

Is the transmission distance
within 20-50 cm?

YES

Go to No. 2-2

NO

Use within
specified distance

2-2

Is the transmisson path
clear of obstacles and
interference?
Is the unit operated away
from TV sets, video, wireles
headphones, incandescent
lamps or other electronic
equipment?
Is the unit operated away
from direct sunlight?

YES  Main PCB 

IC47

IC770

NO

Change operating
environment

1-2

Is the same transmission
protocol set for both the
sending and receiving units?

YES

Go to No. 1-3

NO

Improper setting

4 - 12