Epson MX-80 IIIF/T User manual

EPSON DOT MATRIX PRINTER
Technical Manual
EPSON
P80000001
R EV . A

INTRODUCTION
This technical manual describes the principles of mechanical and
electrical operations, as well as the maintenance and repair pro-
cedures, of the EPSON MX-80 Dot Matrix Printer, to permit the user
to understand its functions and thereby to allow the Printer to fully
display its rated performance.
Chapters 3 through 5 of the manual deal with the fundemental
troubleshooting, maintenance and repair of the MX-80, and Chapter
6, a simple Quick troubleshooting procedure on the basis of a block-
to-block replacement. For details on the disassembly, assembly,
troubleshooting and maintenance of the M-3210 Printer Mechan-
ism, refer to the separately published "Technical Manual of EPSON
Model-321 0."
*The contents of this manual are subject to change without notice.
EPSON
SHINSHU SEIKI CO.,! ... TD.
"All rights reserved."
80 HIROOKA SHIOJIRI·CITY NAGANO JAPAN
REV. A

TABLE OF CONTENTS
CHAPTER 1
GENRAL
1.1 Features of MX-80 ............................................ 1-1
1.2 Features of Interfaces
......................................... 1-1
1.3 Serviceability
... '" ............................................ 1-1
1.4 General Specifications of
MX-80 ............................... 1-2
1.4.1 Printer .................................................... 1-2
1.4.2 Parallel Interface (Standard) ............................... 1-2
1.5 Major Components ............................................ 1-3
CHAPTER 2
PRINCIPLES OF OPERATION
2.1 General ....................................................... 2-1
2.2 Block Diagrams
............................................... 2-1
2.3 Principles of '::>peration
........................................ 2-9
2.4 Electrical Circuits ............................................. 2-9
2.5 Operating Principles of Printer Mechanism ..................... 2-23
2.5.1 Head carriage and paper feeding mechanisms .............. 2-23
2.5.2 Print head ................................................. 2-23
2.5.3 Ribbon feeding mechanism ................................ 2-34
2.5.4 Detecting mechanism ...................................... 2-24
2.5.5 Frame section ............................................. 2-24
CHAPTER 3
DISASSEMBLY, ASSEMBLY AND TROUBLESHOOTING
3.1 General ....................................................... 3-1
3.2 Tools and Measuring Instruments
.............................. 3-1
3.3 Disassembly and Assembly
.................................... 3-3
3.3.1 Removal of Upper Case .................................... 3-3
3.3.2 Disassembly of electric ciucuit block ....................... 3-5
3.3.3 Disassembly of M-3210 printer mechanism block ........... 3-9
3.4 Symptoms of Trouble and Repair ............................... 3-15
3.4.1 General ................................................... 3-1 5
3.4.2 Troubleshooting
by symptom ............................... 3-16
3.4.3 Troubleshooting of control circuit board .................... 3-20
CHAPTER 4
MAINTENANCE
4.1 General ....................................................... 4-1
4.2 Lubrication
.................................................... 4-1
4.2.1 Lubricants ................................................. 4-1
4.2.2 Lubrication standards
...................................... 4-1
4.2.3 Bonding Standards
........................................ 4-2
4.3 Adjustments ......... " ...... , .. , .............................. 4-4
4.3.1 Adjustment of head driving pulse width ..................... 4-4
4.3.2 Adjustment of timing pulse generating position ............. 4-5
4.3.3 Adjustment of phase relationship
between timing signal and reset signal
................•.... 4-6
CHAPTER 5
CIRCUIT DIAGRAMS
5.1 GENERAL ..............................................•.•.... 5-1
5.2 Connection Diagrams
.......................................... 5-1
5.3 Component Layout Drawings
................................... 5-5
CHAPTER 6
SIMPLE TROUBLESHOOTING
6.1 General ....................................................... 6-1
6.2 Troubleshooting
............................................... 6-1
REV. A

LIST OF FIGURES
CHAPTER 3
DISASSEMBLY, ASSEMBLY AND TROUBLESHOOTING
Fig. 3.1 Removal of Manual Paper Feeding Knob ............................... 3-3
Fig. 3.2 Removal of 4 Screws ........... : '.' ................................... 3-3
Fig. 3.3 Locations of Respective Components .................................. 3-4
Fig. 3.4 Dismounting of Driver Circuit Board ................................... 3-5
Fig.3.5 Removal of Control Circuit Board ...................................... 3-6
Fig.3.6 Removal of Power Transformer ........................................ 3-7
Fig.3.7 Dismounting of Fuse and Filter Circuit Board ................... , .. , ... 3-8
Fig. 3.8 Dismounting of M-3210 Printer Mechanism ............................ 3-9
Fig. 3.9 Dismounting of Print Head Unit ....................................... 3-10
Fig. 3.10 Dismounting of Home Position Sensor Assy ............................ 3-10
Fig. 3.11 Unsoldering of Four Lead Wires ....................................... 3-11
Fig. 3.12 Dismounting
of PTS Sensor Board Assy ............................... 3-11
Fig. 3.13 Dismounting of Timing Belt Motor Assy
.............. , ................. 3-12
Fig. 3.14 Unsoldering of Lead Wires ............................................ 3-13
Fig. 3.15 Dismounting of Paper Feeding Motor Assy ...................... , ...... 3-13
Fig. 3.1 6 Dismounting of PE Board Assy .................... , ................... 3-1 4
Fig. 3.17 Normal Waveform of Signal
PSEN ..................................... 3-20
Fig. 3.18 Normal Waveform of Signal ALE. .............................. , .•..... 3-20
Fig. 3.19 Normal Waveform of Signal SyNC ................. , ............. , ...... 3-21
Fig.
4.1
Fig. 4.2
Fig. 4.3
Fig. 4.4
Fig. 4.5
Fig. 4.6
Fig. 4.7
CHAPTER 4
MAINTENANCE
Lube Points and Bonding Points ...................................... 4-3
Applied Voltage vs. Driving Pulse Width ............................... 4-4
Timing Signal PTS (Pin No.39 of 8049). ............................... 4-5
Relationship between Timing Signal and Signal
PRAV ................. 4-5
Adjustment of PTS Sensor Board •............. , ....................... 4-6
Relationship between Timing Signal and Reset $ignal ................. 4-6
Adjustment of Home Position Sensor Assy ................. , ...... , .... 4·7
CHAPTER 5
CIRCUIT DIAGRAMS
Fig. 5.1 Connection Diagram of Control Circuit. ............. , .................. 5-3
Fig. 5.2 Connection Diagram of Driver Circuit .................. , ....... , ....... 5-4
Fig. 5.3 Component Layout of Control Circuit
.................................. 5-5
Fig. 5.4 Component Layout of Driver Circuit ................................... 5-6
REV. A

LIST OF FIGURES
CHAPTER 1
GENERAL
Fig. 1.1 M-3210 Printer Mechanism: ..........................•............... 1-3
Fig. 1.2 Main and Driver Circuit Boards ........................................ 1-3
Fig. 1.3 Power Supply Circuit ................................................. 1-4
Fig. 1.4 Upper and Lower Cases .............................................. 1-4
CHAPTER 2
PRINCIPLES OF OPERATION
Fig. 2.1 Flow of Signals ....................................................... 2-1
Fig.2.2 Component Layout of Fuse & Filter Circuit ............................. 2-9
Fig. 2.3 Connection Diagram of Fuse & Filter Circuit ........................... 2-9
Fig. 2.4 Windings of Transformer .............................................. 2-10
Fig. 2.5 Rectifier and Constant-Voltage Circuit ................................. 2-10
Fig. 2.6 Flow of Data and Signals through 8155 ............................... 2-12
Fig. 2.7 8155 and Peripheral Circuits .......................................... 2-12
Fig. 2.8 Data Transfer SeQuence ........................ ; ..................... 2-13
Fig.2.9 Carriage Stepper Motor Drive Signals (Forward) ....................... 2-14
Fig. 2.10 Paper Feed Stepper Motor Drive Signals ............................... 2-14
Fig. 2.11 8041 and Peripheral Circuits .......................................... 2-15
Fig. 2.1 2 Signal ALE ........................................................... 2-16
Fig. 2.13 8049 and Program Memory Circuits ................................... 2-16
Fig. 2.14 Locations of DIP Switches ............................................ 2-17
Fig. 2.15 DIP Switch Status Read Circuit ....................................... 2-17
Fig. 2.16 Reset (HP Sensor) Circuit. ............................................ 2-18
Fig. 2.17 Timing (PTS) Sensor Circuit .......................................... 2-18
Fig. 2.18 Timing and Reset Detection Signals ................................... 2-19
Fig. 2.19 Driver Circuit ......................................................... 2-19
Fig. 2.20 Current Waveform of Print Head ....................................... 2-20
Fig. 2.21 Applied Voltage vs. Driving Pulse Width ............................... 2-20
Fig. 2.22 Switches and Indicators on control PaneL ............................. 2-21
Fig. 2.23 Switch and Indicator Control Circuit
................................... 2-22
Fig. 2.24 Operation of Print Head ............................................... 2-23
REV. A

LIST OF TABLES
CHAPTER 2
PRINCIPLES OF OPERATION
Table 2.1 Pin Assignment of CN 1 .............................................. 2-2
Table
2.1 Pin Assignment of CN 1 (cont.) ........................................ 2-3
Table 2.2 Pin Assignment of CN2 .............................................. 2-4
Table 2.3 Pin Assignment of CN3 .............................................. 2-5
Table 2.4 Pin Assignment of CN4 .............................................. 2-6
Table 2.5 Pin Assignment of CN5 .............................................. 2-7
Table 2.6 Pin Assignment of CN6
.............................................. 2-8
Table 2.7 Signal Lines from Control Circuit to Control Panel. . . . . .. . . .. . . . . . .. .. 2-21
CHAPTER 3
DISASSEMBLY, ASSEMBLY AND TROUBLESHOOTING
Table 3.1 List of Tools ......................................................... 3-2
Table 3.2 List of Measuring Instruments ........................................ 3-2
Table 3.3 Replaceable Circuit Components ..................................... 3-15
Table 3.4 Replaceable Mechanical Components ................................ 3-15
Table 3.5 Major Components on Control Circuit Board .......................... 3-20
Table 3.6 ..................................................................... 3-21
CHAPTER 4
MAINTENANCE
Table 4.1 List of Lube Points ................................................... 4-1
Table 4.2 List of Bonding Points
................................................ 4-2
CHAPTER 6
SIMPLE TROUBLESHOOTING
Table 6.1 Replaceable Components in Simple Troubleshooting .................. 6-1
REV. A

CHAPTER 1
GENERAL
CONTENTS
1.1 Features of MX-80 ....................................... 1-1
1.2 Features
of Interfaces .................................... 1-1
1.3 Serviceability
............................................ 1-1
1.4 General Specifications of
MX-80 ......................... 1-2
1.4.1 Printer ............................................... 1-2
1.4.2 Parallel Interface (Standard) .......................... 1-2
1.5 Major Components ....................................... 1-3
REV. A

1.1 Features of MX-80
The MX-80 is a serial dot matrix printer featuring 80 CPS bi-directional printing with logical
seeking capability and 9 x 9 dot-matrix character formation, and
is a fruit of our constant
efforts
in pursuit of miniaturization, light weight and high performance. The Printer is thus
capable of fully displaying its intended performance when used with various computers. The
MX-80 also has optional interface boards to permit the connection of the Printer to any of the
computers which are provided with various interfaces.
By merely adding these optional
interface boards to the MX-80, data transfer is possible between the computer and the
MX-80.
1.2 Features of Interfaces
The MX-80 has a Centronics-compatible parallel interface as the standard equipment. With
this standard interface, the MX-80 can be connected to any of various personal computers
for data communication.
In addition to the standard interface, the MX-80 has the following interface options which
permit the user to connect his Printer to almost all the computers equipped with various
interfaces.
(1) RS-232C/Current Loop Serial Interface
This optional interface is bf a 20mA/60mA current loop type which is the same
as the
level prescribed for serial interfaces by the
EIA Standards, TTY, etc., and permits the
Printer to receive data at a bit rate ranging from 75 to 9,600 BPS.
(2) IEEE 488 Interface
This optional interface has the bus structure defined by the
IEEE Std. 488-1975, and per-
mits the Printer to be connected parallelly to any computer or measuring instrument
which
is equipped with this bus structure. Thus, information such as measured data, etc.
from the computer or measuring instrument can be recorded
on the MX-80 printer.
(3)
APPLE II Interface
This optional interface permits the MX-80 to transfer data to and from
an APPLE II (or 1\
Plus) personal computer manufactured by the Apple Computer Inc. when it is incorpor-
ated into the computer.
(4) TRS-80 Interface
This optional interface
is connected to the bus system of a TRS-80 computer manufac-
tured by the Tandy Radio Shack, to permit printing of the TRS-80 programs and other
data
on the MX-80.
As described above, the MX-80 is configured to cope with various interfaces. For further
information
on the respective interface options, refer to the user manual separately
published for each interface.
1.3 Serviceability
The MX-80 has been designed to minimize maintenance and repair in operation under its
normal
use.
Should maintenance or repair be required, the printer mechanisms and circuit boards of the
MX-80 are readily replaceable. Access to the respective mechanical components can be
obtained easily. Accordingly, the user is permitted
to perform minimum maintenance and
repair with ease by referring to this manual.
1-1
REV. A

1.4 General Specifications of MX-80
1.4.1 Printer
(1) Printing Method ............ Impact dot matrix
(2) Character Set .............. ASCII' 96 + Graphic 64 + 9 special
characters/symbols (Selectable by oper-
ator)
(3) Character Font . . . . . . . . . . . .. 9 x 9 dot matrix
(4) Character Size ., ... " .. " .. 2,1 mm (W) x 3.1 mm (H) (0.08" x
0,12")
(5) Paper Feed " .... , .... , .... Adjustable sprocket feed
(6) Paper ................ ,.... Fanfold paper
(7) Paper Width ........... ,... 101.6 mm (4") -254 mm (10")
(8) Copies .. , .... " .. ,',.,.," One original plus two carbon copies
(9) Paper Thickness, , , , , , , , , , " 0,3 mm (G,01 ") max.
(10) Line Spacing, , . , . , ... , ... '. 4.23 mm (1/6") or programmable
(11) Columns" .. "".",.,." .. 80 (Normal size)
40 (Enlarged size)
132 (Condensed size)
66 (Condensed-enlarged size)
(12) Print Speed ., .. , . ,. ,. ,. , , ,. 80 CPS (Normal)
(13) Ribbon , .. ,.'."'.".,.,". Cartridge Ribbon (exclusive use), Black
(14) Dimensions,.,.,."", .. ". 374 mm (W) x 305 mm (D) x 107 mm
(H)
(14.7"x 12,0"x 4.2")
(15) MTBF , .. ,"', .. "., .. ,., .. 5 x 106 lines (excluding print head)
(16) Print Head Life ... , .. , , , .. " 100 x 106 characters
1.4.2 Parallel Interface (Standard)
(1) Date transfer rate .. , . , , .. , .' 1,000 CPS (max.)
(2) Synchronization", .... " .. , By externally supplied STROBE pulses.
(3) Handshaking .... ,., .. ,., ... By ACKNLG or BUSY signals
(4) Logic level .. , , , . , . , , ... , , .. Input data and all interface control sig-
nals are compatible with the TTL level.
REV, A 1-2

1.5 Major Components
The MX-SO consists, in a broad classification, of the following four major components.
(1) Model 3210 printer mechanism
This mechanism
is an assembly of all the mechanical functions of the MX-SO, and con-
sists mainly of two stepper motors, a print head, a ribbon feeding mechanism, a carriage
assembly, sensors and a frame section. One stepper motor functions
as the print head
carriage motor, while the other works
as the paper feeding motor. The M-321 0 has been
designed extremely simple
to permit easy maintenance as described later in this
manual.
Fig. 1.1 M-3210 Printer Mechanism
(2) Circuit boards
The
MX-SO is provided with two printed circuit boards as the standard equipment. One
printed circuit board functions as a main circuit board (control circuit board) with an LSI
S049 for printer control. On the main circuit board, the other printed circuit board serving
as a driver circuit board is secured with two screws. The M-321 0 is controlled through
the 2S-pin connector attached to the driver circuit board.
Main Circuit Board Driver Circuit Board
Fig. 1.2 Main and Driver Circuit Boards
1-3
REV. A

(3) Power supply circuit
The power supply circuit is partially located on the main circuit board. However, the
power transformer and line filter are mounted separately
on the lower case. The power
supply circuit supplies all the voltages required for the MX-80.
The line filter consisting
of capacitors blocks noises
to and from an external source.
Fig. 1.3 Power Supply Circuit
(4) Housing
The housing of the MX-80 consists of an upper case anda lower case, and accommo-
dates all the components described
in paragraphs (1), (2) and (3) above. The lower case
has been designed to facilitate mounting of the above-mentioned components.
Fig. 1.4 Upper and Lower Cases
REV. A 1-4

CHAPTER 2
PRINCIPLES OF OPERATION
CONTENTS
2.1 General ................................................ 2-1
2.2 Block Diagrams
........................................ 2-1
2.3 Principles of Operation
................................. 2-9
2.4 Electrical Circuits ...................................... 2-9
2.5 Operating Principles of Printer Mechanism .............. 2-23
2.5.1 Head carriage and paper feeding mechanisms ....... 2-23
2.5.2 Print head .......................................... 2-23
2.5.3 Ribbon feeding mechanism .......................... 2-24
2.5.4 Detecting mechanism ............................... 2-24
2.5.5 Frame section ...................................... 2-24
REV. A

2.1 General
This chapter provides the descriptions of signals at the various connectors electrically inter-
connecting such major components units
as printer mechanism, driver circuit board, control
circuit board
and control panel of the EPSON MX-80 Dot Matrix Printer, and explains the
operating principles of the various mechanisms around the electric circuits of the Printer.
2.2 Block Diagrams
The flow of signals through the respective major components of the MX-80 is shown in Fig.
2.1.
Power filter
M-3210 Printer Mechanism
Driver circuit board
Control circuit board
CN3 (26-pin,
female-type)
I===~~ AC 115/220/240V
Fig. 2.1 Flow of Signals
Refer to Tables 2.1 through 2.5 for the pin assignments of respective connectors.
2-1
REV. A

(1) Connector CN1
(a) Use ................... This connector is used for data exchange between the
MX-80 and an external computer (parallel).
(b) Number of pins ........ 36 pins
(c)
Part number ........... 57-30360 (AMPHENOL)
(d) Pin assignment ......... Refer to Table 2.1 below.
Table 2.1 Pin Assignment of eN 1
Signal
Return
Signal Direction Description
Pin No.
Pin No.
1 19 STROBE
In STROBE pulse to read data in. Pulse width must be
more than
0.5j1.s at receiving terminal.
The signal level is normally "HIGH"; read-in of data is
performed at the "LOW" level of this signal.
2 20
DATA 1 In
These signals represent information of the 1st to 8th
3
21
DATA 2
In
bits of parallel data respectively. Each signal is at
"HIGH" level when data is logical "1" and "LOW"
4 22 DATA 3
In
when logical "0".
5 23
DATA 4
In
6 24
DATA 5 In
7 25
DATA 6 In
8 26
DATA 7 In
9
27 DATA 8
In
10 28 ACKNLG Out Approx.
5/Ls pulse. "LOW" indicates that data has
been received and that the printer
is ready to accept
other data.
11
29
BUSY Out A "HIGH" signal indicates that the printer cannot
re-
ceive data. The signal becomes "HIGH" in the follow- I
ing cases:
1. During data entry
2. During printing operation
3. In OFF-LINE state
4. During printer error status.
12
30
PE
Out A "HIGH" signal indicates that the printer
is out of
paper.
13 -
SLCT Out This signal indicates that the printer
is in the selected
state.
14 -
AUTO FEED XT In
With this signal being at "LOW" level, the paper is
automatically fed one line after printing.
(The signal level can be fixed to "LOW" with
DIP SW
pin 2-3 provided on the control circuit board.)
15 -
NC
Not used.
16 -
OV
Logic GND level.
17 -CHASSIS-GND -Printer chassis
GND.
In the printer, the chassis GND and the logic GND are
isolated from each other.
18 -
NC
-Not used.
19 to 30 -GND -TWISTED-PAIR
RETURN signal GND level.
REV. A 2-2

Table 2.1 Pin Assignment of CN1 (cont.)
Signal Return
Signal Direction Description
Pin No. Pin No.
31
-INIT
In
When the level of this signal becomes "LOW", the
printer controller
is reset to its initial state and the
print buffer is cleared. This signal is normally at
"HIGH" level, and its pulse width must be more than
50ILs at the receiving terminal.
32
ERROR Out
The level of this signal becomes "LOW" when the
printer is in-
1. PAPER END state
2. OFF-LINE state
3. Error state
33 -GND -Same as with
Pin Nos. 19 to 30.
34 -
NC
-Not used.
35 Pulled up to
+5V through 4.7 kfl resistance.
36 -SLCTIN
In
Data entry to the printer is possible only when the
level of this signal is "LOW" (Internal fixing can be
carried out witn
DIP SW pin 1-8. The condition at the
time
of shipment is set "LOW" for this signal.)
NOTES 1: "Direction" refers to the direction of signal as viewed from the printer.
2: "Return" denotes "TWISTED PAIR RETURN" and is to be connected at signal ground level.
As to the wiring for the interface, be sure to use a twisted-pair cable for each signal and never fail to
complete connection on the Return side. To prevent noise effectively, these cables should be shielded
and connected to the chassis of the host computer and the printer, respectively.
3: All interface conditions are based on TTL level. Both the rise and fall times of each signal must be less
than 0.2 ILS.
4: Data transfer must not be carried out by ignoring the ACKNLG or BUSY signal.
(Data transfer to this printer can be carried out only after confirming the ACKNLG signal or when the
level of the BUSY signal is "LOW".)
2-3
REV. A

(2) Connector CN2
(a) Use ................... This connector is used to supply the required AC
voltages to the control circuit board.
(b) Number of pins
........ 8 pins
(c)
Pin assignment ......... Refer to Table 2.2 below.
Table 2.2 Pin Assignment of CN2
Pin No.
Signal Name Color of Lead Purpose
1 + 12V AC
Gray
2 + 12V
AC
Gray
For optional interfaces
3
+25V AC
Orange
4 +25V AC
Orange
For stepper motor
5
+9V AC
Red
6 +9V AC
Red
For logic circuitry
7 + 10V AC
Blue
8 + 10V
AC Blue
For stepper motor
REV. A 2-4

(3) Connector CN3
(a) Use ................... This connector is used when connecting an optional P.C.
board to the MX-80.
(b) Number of pins
........ 26 pins
(c)
Pin assignment ......... Refer to Table 2.3 below.
Table 2.3 Pin Assignment of eN3
Connector Signal Name Description of Signal Direction
Pin No.
1
ERR Error Out
2
PE Paper End
Out
3
D7 Data Bit 7
In
4
RDY (BUSY)
Ready Out
5
D6 Data Bit 6 In
6 ACK Acknowledge Out
7 D5/PAR
DIS
Data Bit 5/Parity Disable
In
8 INIT Initial In
9 D4/0/E Data Bit
4/0dd Parity Select/Even Parity
In
Select
10
STB Strobe
In
11 D8/S1 Data Bit 8/Serial Signal Input
In
12
+12
+12V AC Out
13 R Reset Out
14
+12
+12V AC Out
15 D3/B2 Data Bit 3/Bit
Rate Select In
16
+5
+5V DC
Out
17 D2/B1 Data Bit 2/Bit Rate Select
In
18
+24
+24V DC Out
19 D1/8/7 Data Bit 118 Bit Selectl7Bit Select In
20
+12
+ 12V DC
Out
21
PIS
Parallel Select/Serial Select
In
22 - - -
23
SELIN Select In In
24
GL
Ground -
25
PET TRS PETITRS Select In
26 GL Ground -
NOTE: "Direction" refers to the direction of signal flow as viewed from the control circuit board.
2-5
REV. A

(4) Connectors CN4
(a) Use ................... Two CN4 connectors (one with male contacts and the
other with female contacts) are used
to supply control
signals between the control circuit board and driver cir-
cuit board of the MX-80.
(b) Number of pins ........ 22 pins
(c)
Pin assignment ......... Refer to Table 2.4 below.
Table 2.4 Pin Assignment of CN4
Connector Signal Name Description of Signal Direction
Pin No.
1
GP
Ground Level -
2
GP Ground Level -
3 -- -
4 ---
5
GP
Ground Level -
6
GP
Ground Level -
7 H8 Head Solenoid Drive Signal Out
8 H7 Head Solenoid Drive Signal Out
9 H6 Head Solenoid Drive Signal Out
10 H5 Head Solenoid Drive Signal Out
11 H4 Head Solenoid Drive Signal Out
12 H3 Head Solenoid Drive Signal Out
13 H2 Head Solenoid Drive Signal Out
14
H1
Head Solenoid Drive Signal Out
15 H9 Head Solenoid Drive Signal Out
16 (555Q) -
In
17 R Reset
In
18
PE
Paper End
In
19 CRB
Phase B for Carriage Stepper Motor Drive Out
20 (132 Columns) -Out
21
(FP) -Out
22
CRA
Phase A for Carriage Stepper Motor Drive Out
NOTE: "Direction" refers to the direction of signal flow
as viewed from the control circuit board,
REV. A 2-6

(5) Connectors CN5
(a) Use ................... Two CN5 connectors (one with male contacts and the
other with female contacts) are use to supply control sig-
nals between the control circuit board and driver circuit
board of the MX-80.
(b) Number of pins ........ 22 pins
(c)
Pin assignment ......... Refer to Table 2.5 below.
Table 2.5 Pin Assignment of eN5
Connector Signal Name Description of Signal Direction
Pin No.
1 CRD Phase D for Carriage Stepper Motor Drive
In
2
LFB
Phase B for Paper Feed Stepper Motor Drive
In
3
SLF
Line Feed Activate
In
4
CRC
Phase C for Carriage Stepper Motor Drive In
5 (80 columns) -Out
6
LFC
Phase C for Paper Feed Stepper Motor Drive
In
7 Head Trigger Timer Triggering Signal
In
8
LFA
Phase A for Paper Feed Stepper Motor Drive
In
9 RS
Home Position Signal Out
10
LFD
Phase Dfor Paper Feed Stepper Motor Drive
In
11
PTS
Clock Input Out
12 GL Ground -
13 GL Ground -
14 +24 +24V DC
In
15 +24
+24V DC In
16
+24
+24V DC
In
17 +24
+24V DC
In
18
+5
+5V DC
In
19 - - -
20 - - -
21 Vx
Power Failure Detection Signal In
22 +14 +14V DC
In
NOTE: "Direction" refers to the direction of signal flow as viewed from the driver circuit board.
2-7
REV. A

(6) Connectors CN6
(a) Use ................... Two eN6 connectors (one with male contacts and the
other with female contacts) are used
to supply control
signals between the M-321 0 printer mechanism and the
driver circuit board
of the MX-80.
(b) Number of pins
........ 28 pins
(c)
Pin assignment ......... Refer to Table 2.6 below.
Table 2.6 Pin Assignment of eN6
Connector Signal Name Description of Signal Direction
Pin No.
1
H1 Head Driving Signal In
2 H2 Head Driving Signal
In
3 H3 Head Driving Signal
In
4 H4 Head Driving Signal
In
5 H5 Head Driving Signal
In
6 H6 Head Driving Signal
In
7 H7 Head Driving Signal
In
8 H8 Head Driving Signal
In
9 H9 Head Driving Signal
In
10
SOL Solenoid common line +24V In
11 SOL
Solenoid common line +24V
In
12 V+5
+5V In
13 SCR Carriage Stepper Motor Current Liimiting In
Signal
14
SLF
Paper Feed Stepper Motor Current Limiting
In
Signal
15 GLED
Ground level -
16 GPE
Ground level -
17 GR
Ground level -
18 PE
Paper End Signal from Printer Mechanism Out
19 PTS
Timing Signal from Printer Mechanism Out
20
RS
Reset Signal from Printer Mechanism Out
21 CRA
Carriage Drive Signal In
22
CRB
Carriage Drive Signal
In
23 CRC
Carriage Drive Signal In
24 CRD
Carriage Drive Signal In
25
LFA
Paper Feed Drive Signal
In
26
LFB Paper Feed Drive Signal In
27 LFC
Paper Feed Drive Signal In
28 LFD
Paper Feed Drive Signal
In
NOTE: "Direction" refers to the direction of signal flow as viewed from the Printer Mechanism.
REV. A 2-8