Epson FX Series User manual

11
•
I-'
.1
r •
EPSON
FX,RX,MX
PRINTERS
Product
Support
Supplement
The
Centre
for
Computing
History
ff
www.CompulingHistoiy.org.uk

EPSON FX, RX, & MX PRINTERS
PRODUCT SUPPORT SUPPLEMENT
600P89074
FEBRUARY 1986
Prepared by:
Curriculum Development Service's
XICTMD/Service Training
XEROX
« Copyright 1986 by Xerox Corporation
Allrights reserved
Epson FX. RX, and MX are registered trademarks of
Epson America, Inc.
PRINCIPLES OF OPERATION 1
WIRING DATA

EPSON PRINTERS CONTENTS
INTRODUCTION
Introduction ii
How to use this Manual ii
1 PRINCIPLES OF OPERATION
1.1 Principles of Operation 1-1
2 WIRING DATA
2.1 Introduction 2-1
2.2 FX-85/185 2-2
2.3 FX-80/100 2-6
2.4 RX-80/100 2-10
\JiSy 2.5 MX-80/100 2-13

INTRODUCTION
INTRODUCTION
This manual contains detailed principles of operation, electrical description,
and wiring information for the Epson FX, RX, and MX family of dot matrix
printers. It should only be used by Xerox Service Center leaa technicians or
service representatives.
HOW TO USE THIS MANUAL
Start with the Product Support Manual. If the Printer has a unique problem
that the PSM does not support then refer to the appropriate Principles of
Operation, Electrical Description, or Wiring section of this manual. The
schematic diagrams are provided to assist you in isolating components that
are field replaceable.
EPSON PRINTERS

EPSON PRINTERS
1.1 PRINCIPLES OF OPERATION
The descriptions of the printer mechanics is generic to all models with few
exceptions.
O
PRINTER MECHANISM
Theprinter mechanisms are dot matrix mechanisms withsub-miniature print
heads developed for high quality, precision printing. Because some the units
come with tractor feed attachments and also are equipped with rubber
plates,they maybe usedwith continuousbusiness forms or rolledor cutsheet
paper, as required by the user. No special additional equipment need be
purchased to accommodate the various paper types. Basic operation of all
the models is essentially the same.
Sensor Mechanisms
Sensor mechanisms on all models include the home position (HP), print
^ timing (PTS), and the paper end (PE) sensors.
Home Position (HP) Sensor
The HP sensor assembly consists of a HP sensor and a sensor plate,
situated beneath the carriage assembly. The sensor emits a HIGH signal
whenever the sensor plate intercepts the optical axis of the photo
sensor. The variations in the signal alert the main CPU as to when the
carriage isin or out of the home position (i.e. the left end of the platen).
This signal servesas a
reference signal for the printing operation.
^ Print Timing Sensor (PTS)
The PTS sensor mechanism consists of the sensor and a sensor disk,
located on the shaft of the carriage motor. The PTS signal is generated
in order to coordinate carriage speed with firing of the dot wires,
allowing adequate time for the print operation to be performed. A
HIGH signal isemitted asthe slits inthe disk pass the optical axis of the
photo sensor.
1-1
PRINCIPLES OF OPERATION
Paper End (PE) Sensor
The PE sensor consists of a reed switch mounted on the PE sensor board
and a reed magnet mounted on a PE sensor lever. The assembly is
attached at the rear of the printer mechanism. When the printer runs out
of paper, the reed magnet and reed switch meet causing the PE warning
signal to be output.
PRINT ASSEMBLY
The print assembly is comprised of the carriage assembly, including the
carriage motor, timing belt, and platen; ancf the print head, which is
mounted on the carriage assembly.
Carriage Assembly
The carriage assembly is moved back and forth along the carriage shafts
by the timing belt, which is driven by the carriage motor via the belt
driven pulley. (Figure 1-1)
Carnage
Carnage motor
Timing belt
Fig. 1-1. Carriage Mechanism

PRINCIPLES
OF
OPERATION
The
carriage
motor
isa 2-2
phase
stepper
motor.
C
phase
A
phase
D
phase
(ROTORl B
phase
Q
••
—o-
Fig.1-2. Carriage
Motor
Connections.
The
timing
belt
drive
sequence
is
demonstrated
in
Table
1-1, As
the
carriage motor rotates,
PTS
pulses
are
generated,
energizing
the
head
driving coils,which inturn fire
the
dot
wires housea in
the
print head.
TABLE
1-1. Carriage
Motor
Step
Sequence
Carriage
Motion
Step
Na
A
phase
Bphase
C
phase
D
phase
1
ON
OFF OFF
ON
l.«ft
-
tight
2
ON
OFF
ON
OFF
3
OFF
ON ON
OFF
4
OFF
ON
OFF
ON
1ON OFF
''
ON
OFF
Right left 2
ON
OFF
OFF
ON
3
OFF
ON
OFF
ON
4
OFF
ON
ON
OFF
As
the
carnage
motof
rotates.
PTS
pulses
are
senerated.
energizing the
head
driving coils, which in lurn
fire
the
dot
wires
housed
in
the
print
head.
1-2
EPSON
PRINTERS
Printing
Operation
When
the
head driving coilfor a
dot
wire isenergized,
the
actuating plate
engaaed
at
one
end
of
the
dot
wire is
attacheclto
the
iron core, driving
the
dot
wore toward
the
platen. The
dot
wire,thus driven, strikes
the
ribbon, pressing it against
the
paper
on
the
platen assembly,
and
causing
a
dot
to
be
imprinted.
When the head driving coil is de-energized, the actuating plate spring
recoils,
causing
the actuating plateto
spring
back
to it's
original
position.
Thedot wirealsosprings backunderthe combined forceof
impact
energy
and the recoilof
the
wire resetting spring, and isagain engaged with
the
actuating plate until
the
next print
head
drive signal occurs. Firingof a
dot
wire isdepicted in Figure 1-3.
Wire reset spring
Stopper
Actuator
plate
Ooi
wire
Ribbon
mask
Ribbon
• Iron
core
Paper
'^Actuator
plate
spring
Fig. 1-3.
Print
Mechanism
Platen

EPSON
PRINTERS
PAPER
FEED
MECHANISM
The
Model
3510/3560
mechanisms
are
adaptable
for
use
with
different
paper
types. The Model 3510 has
three
paper
feed options: friction, pin platen, or
sprocket
feed,
and
utilizes
three
paper
types: roll,
cut
sheet,
or continuous
business
form.
The Model 3560
operates
with
both
friction
and
sprocket feed,
and
may be
used
with
continuous
business
forms
or
cut
sheet
paper.
Friction Feed System (For Rollor Cut
Sheet
paper)
The friction
feed
system permits use of roll (Model 3510 only) or
cut
sheet
paper, which is fed
through
the
platen
assembly
between
the
paper
feeding
and
paper
holding rollers.
Paper
support
roller
Paper
feed
roller
Platen
gear
Platen
Paper
feed
gear
Fig.1-4. Friction Feed Mechanism
Paper
tead
motor
1-3
PRINCIPLES
OF
OPERATION
Pin Platen Feed System (For Continuous Business Forms 9.5
and
10 Inches
in Width/Model 3510 only)
In
the
pin
platen
feed
system,
paper
is
held
in place
on
platen
sprocket
pins
on
the
platen
shaft.
When
the
paper
feed
pulse
motor
rotates,
the
platen
aear
train
is
driven,
rotating
the
gears
as
illustrated
in
Figure
1-5,
and
pulling
the
paper
along
on
the
sprocket
pins.
When
the
pin
platen
feed
system is
used,
the
paper
feed
rollers
are
held
apart
by
the
release lever, since no friction is required
for
movement
of
tne
paper.
Platen
Sprocket
ptn
Sprocket
wheel
Platen
gear
Paper
feed
motor
Fig. 1-5. Pin Platen Feed Mechanism

PRINCIPLES OF OPERATION
Sprocket Feed System (For Continuous Business Forms)
Similar
to the pin platen feed operation, in the sprocket feed system,
perforations on the paper margins are fitted over the pins on the
sprocket wheel, the paper islocked in place bya paper holding cover,
and is drawn through the platen assembly astne gear train is activated
by the paper feed motor (Fig. 2-6).
- sprocket pin
Sprocket wrteel
Sprocket gear
Sprocket transmission gear
Paper feed gear
/ Paperfeed motor
Platen gear
Fig. 1-6. Sprocket Feed Mechanism
1-4
EPSON PRINTER
RIBBON FEED MECHANISM
The ribbon feed unit of the Printer mechanism consists of a cartridge ribbon
and a ribbon feeding mechanism which is set on a belt tension plate
assembly. The right or left motion of the timing belt is transmitted to the
ribbon drive gear through the gears on the belt tension plate. Due to
conformation of the gear train, the ribbon is always fed in a counter
clockwise direction.
When the ribbon feed roller is driven by the ribbon drive gear, the
continuous loop, inked ribbon is wound between the ribbon feed roller and
the ribbon support roller. The ribbon brake spring is set at the exit of the
cartridop case to prevent slack as the ribbon is wound in.
Ribbon laading roller
\o,
Ribbon pressure roller
Ribbon mask
Planstdry pmiori I
Planatary pmion .. Ji
Ribtwn braking spring
Ribbon driving gear
Planetary pmion .4
Pldneidty pinion 3
Bell
drivan
Iley
Carriage
Fig.1-7. Ribbon Feed Mechanism

EPSON PRINTERS
ELECTRICAL CIRCUITRY
Power Circuit
The AC input power is supplied to the power transformer through the filter
circuit. The outputs from the secondary side of the power transformer are
input to the circuit board and converted into DC voltages via the regulator
circuit. These DC voltages are supplied to their respective corresponding
electronic circuits.
FX-80+/100+
Filter
Circutt
Power
Trans
former
AC
r
♦5V O-
+24V O-
VX08 (option)
Rogulator
Circuit
n
F)^^ircuU_Bo^ _j
Fig.1-8. BlockDiagram of Power Circuit
FX-8S/185/105
fXEXT
-O +5V
-O +24V (Vp)
-O +12V
-O -cBV
-O VKp
-o Vkc
AC12V
1-5
Voltago
+24V
(VPI
♦5V
(Vcc)
♦ lav
_AC12V
Vkc (♦6V)
Vx P|t5V|
PRINCIPLES OF OPERATION
TABLE 1-2. Types and Applications of Power
Application
CD CorriBO motor driva
(|) Paper feed motor driva
(D Print solenoid drive
(i) li>iertaceoption circuit board power
t'T) FXMB logiccircuitdrive
(X) Carnagemotor tiolding
CD Paper feed motor holding
® Indicator lamp drive
Cjij Interface option circuit board power
Cf) FXEXT logiccircuitdnve
(I; Interface option circuit board power
(D Interface option circuit board power
CD Power reaei
(I) Buzzerpower
(D Print solenoid protection

PRINCIPLES OF OPERATION
Filter Circuit
The filter circuit is situated on the FFIL circuit board together with the
printer power switch and fuse. The power cable is also, connected to the
iPilter board.
The AC input from the power line first flows across the power switch
and fuse F1. After being filtered out by C1, it issupplied to the primary
side of the power transformer via the LC noise prevention circuit. Power
line noise (external noise) into the printer and noise (internal noise)
occurring from the printer are eliminated by this noise prevention
circuit. Capacitors C2 and C3 are not used for the 120\/ version.
sw
Fl
L O-
. d\j>
SOOajH C2 ^ i.700P
C1 dp O lpF
CN1
C3 iz 4700P
N O-
>N>.
-O
Fig. 1-9. Fuse and FilterCircuit
1-6
EPSON PRINTERS
Power Transformer
In the Printer, the power transformer changes the AC input into AC 26V
and 12VAC through the filter circuit and supplies necessary voltages to
the control circuit and option interface circuit.
PRIMARV PRIMARY
flCitC. o-
AClZOv o-
Bl ACK
SECONOARy
orange
SECONDARY
o
50/60HZ
Ov o-
TF
Pgray"
I flfay
wange
orange
AC9.1V
AC27 7V
o-
50/60H2
Ov O-
BROWN
white
iQfay
Ofange
orange
120V Version 220/240V Version
Fig. 1-10. Power Transformer Windings
AC9.0V
AC29.8V