General Operating - Epson MX-80 IIIF/T Technical Service Data

GENERAL OPERATING
INSTRUCTIONS
PRINT
STATUS
(SW1)
AND
LINE
FEED STATUS
(SW2)
PRINTER SELF-TEST
SW1 On
1
Compressed
2
Not Used
3
Paper Out Sensor On
4
Italic
5
Emphasized
6
Buzzer
On
7
Slashed Zero
8
Select Fixed
On
Not
Used
Not
Used
Auto
Line
Feed
with
Carriage Return
One
Inch Skip Over
Pert
Off
Normal
SW2
1
2
3
Paper Out Sensor
Off
Normal
Normal
Buzzer Off
Regular Zero
Select
Not
Fixed
Off
Line
Feed from Host
Normal (No
Skip)
To use
the
built-in self-test
function, put
paper
in
the
printer
and
hold
down
the
LF
(Line
Feed) button while turning
On
the
printer.
ON
LINE,
FF
AND
LF
BUTTONS
Printer
is
On
Line
(Ready
to receive
data from the computer)
when
all
three
green LED's
are
On.
The
printer
is
Off Line
when
only the top green
LED
is
On. Pressing the
On
Line but-
ton
once
puts the printer Off Line
and pressing
it
again puts
the
printer
back
On
Line.
The
printer
must
be Off Line
for
the
FF (Form
Feed)
and LF
(Line
Feed) buttons
to function.
ADJUSTMENTS
HEAD
DRIVER PULSE WIDTH ADJUSTMENT
Connect
the input
of a
scope
to
Test
Point
TO
on
the Driver
Board and
set the horizontal
sweep
to
.1
ms
trigger to positive
edge.
Use the
printer
self-test
mode
(Hold
LF
button
down
while turning
On
the
printer) to
make
the printer
print.
While
the printer
is
printing, adjust the Pulse
Width
Control (VR1)
for
a pulse width
of
.32ms. See Figure
1.
Connect Channel B
input
of
the
scope
to pin 28 of IC
1C and
set the trigger to trigger
on Channel
B,
negative edge, normal
mode. Check
for a
time d ifference
of
.8ms
or
more
from
the
trailing
edge
of
the
PRAV
signal
on
pin 28
to
the leading edge
of
the
first
pulse
of
the TIN
signal
on
pin 39.
If
the time
dif-
ference
is
less than .8ms, readjust the
PTS Sensor Board
slightly for
a difference
of
.8ms
or
more. See Figure
3.
Figure
1
TIN
PRAV
"1
Figure
3
PTS
SENSOR BOARD ADJUSTMENT
HOME
POSITION
SENSOR ADJUSTMENT
Connect Channel A
of a dual trace
scope
to pin 39
of
Microcomputer
IC (1C)
and
set
the horizontal
sweep
to
,5ms,
trigger to positive edge.
Use
the
printer self-test
mode
(Hold
LF
button
down
while turning
On
the
printer) to
make
the
printer
print.
Loosen
the
screw
holding the
PTS
(Position
Timing
Signal)
Sensor Board
to the
right
side
of
the carriage
return
motor.
Use
a
screwdriver
in
the
slot
provided
to adjust
the
PTS
Sensor Board
for
a pulse cycle
of
2.08ms
while the
printer
is
printing.
See
Figure
2.
Connect Channel A
input
of
a dual
trace
scope
to pin
1 1
of IC
3E and Channel B
input to pin 39
of
IC(1C). Set the horizontal
sweep
to
.5ms and
set
the
trigger for
Channel
A, positive
edge,
normal mode. Use
the printer self-test
mode
(Hold LF
button
down
while turning
On
the printer) to
make
the
printer
print.
Loosen
the screw holding the
Home
Sensor Board and
use
a screwdriver
in
the
slot
provided
to
adjust the
Home
Sensor Board
for
a
phase
relationship of
.9ms
to
1.2ms
bet-
ween
the reset signal
on
pin 11 of IC
3E and
the
TIN
signal
on
pin
39
of
IC 1C.
See
Figure
4.
U-2.08ms-*|
Figure
2
TIN
RESET
SIGNAL
i r
9ms
to
1.2ms
Figure
4
I
10