Epson FX-80 Technical Service Data page 3

PRELIMINARY SERVICE
CHECKS
(Continued)
SERVICE
CHECKS
SEE
INTERCONNECTING DIAGRAM
AND PHOTOS
TO MATCH
THE
NUMBER
IN
THE
CIRCLES WITH
THOSE
IN
THE FOLLOWING DATA FOR
SERVICE
CHECKS
TO BE
PER-
FORMED.
©
1.)
PRINTER
DEAD
©
©
(A)
Check
AC
Fuse
(F1).
If
Fuse
is
open, disconnect the
power
transformer Connector CN6, switch
the
Printer
On
and check
for
28.0V
AC
between
pins
1
and
2 of
Connector
CN6
and
for
7.6V
AC
between
pins 3
and
4 of
Connector CN6.
(B)
if
voltages
are
missing, check Power Switch
(SW1A),
AC
Fuse
(F1),
AC
Power
cord
and
also
check Power Transformer
(T1)
windings
with
an
ohmmeter.
(C)
!f
the voltages are present, check
the
Diode DB1
for
a short.
Replace
or Troubleshoot the
FMBD
Board.
WILL
NOT
RECEIVE DATA
FROM COMPUTER
(A)
Check
connector cable
between
the Printer
and
the
Computer.
(B)
Check Connector CN5, check
the Printhead cable
for
broken
or cracked
circuits
and check
the con-
nection
at
Printhead cable Terminal Board connec-
tor.
PRINTHEAD WILL
NOT
PRINT
(A)
Remove
power and check
resistance
of
the
Print-
head (HD) Solenoids by removing Connector CN5.
Check
the resistance
for
each solenoid.
Each
solenoid should measure
about 20
ohms.
If
the
resistance checks
incorrect, replace the printhead.
(B)
Check
for
24.0V
at
pins
14,
15
and
16 of
Connector
CN5.
©
PRINTHEAD HAS
MISSING
DOTS
(A)
Check
the resistances
of Printhead (HD) solenoids
(20
Ohms).
The
Solenoid which controls missing
dot
will
measure
incorrectly.
If
all
the
Solenoids
measure
correctly,
check
for
possible bent
or
broken
Printhead
wires.
(B)
Check
the Printhead cable
for
cracks and
for
good
connection.
(C) If
the Printhead
is
normal,
check
the
Microprocessor
IC (3B) by substitution.
(D)
If
Microprocessor
IC (3B)
checks
good, replace or
troubleshoot the
FMBD
Board.
©
5.)
PAPER FEED DOES NOT FUNCTION
(A)
Check
for
22.5V
at
pins
11
and
12
of
Connector
CN4
while the
Printer
is
printing.
(B)
If
the 22.5V
is
missing, check the 24.0V
at
TP
VP.
(C)
Check
resistances
of
the Paper Feed Motor
(M4)
windings and
replace
Motor
M4
if
defective.
(D)
If
the Motor
M4
checks
good,
check Connector CN4
for
good
contacts and
also
check Microprocessor
IC
(3B).
(E)
If
replacement
of IC
3B does
not correct the
pro-
blem, replace
FMBD
Board.
@CARRlAGE
(TIMING BELT)
MOTOR
DOES FUNCTION
PROPERLY
(A)
Check
the timing
belt
engagement on
the bottom
of
the carriage assembly.
(B)
Check
the adjustment
of the
PTS
(Position Timing
Signal)
Sensor
(M2).
(C)
Check
the resistance
of the
windings
of Carriage
(Timing
Belt)
Motor
(M3).
(D)
Check
the adjustment
of the Carriage
Motor
assembly and check
for
MINIMUM
lash
between
the
gears without gears
locking
up.
©
POOR
QUALITY PRINT
(A)
Ribbon
Cartridge
may
be worn and due
to
be
replac-
ed.
(B)
See
if
the ribbon
advances and
is
not
jammed.
Also
check gear assembly
for free
movement.
(C)
Check
the spacing
between
Printhead (HD) and
the
Platen and
also
check
position
of
the
Head
Adjust-
ment
Lever.
(D)
Check
for
a defective Printhead.
(£)
PAPER EMPTY INDICATOR DOES
NOT
FUNCTION
(A)
Check
the continuity
of the Paper
Empty
Switch
(SW99).
(B)
Make
certain
Connector
CN8
is
making good
con-
tact.
(C)
Make
certain Dip Switch (SW1-3)
is
set
in
the Off
position.
(D)
Check
for a malfunction
in
the control panel by
substitution
of
Control Panel Assembly.