Epson MX-80 IIIF/T User manual

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MX-BO
EPSON DOT MATRIX PRINTER
Technical Manual
NORTHAMBER LIMITED
CHEAT OAK HOUSE, ALBANY CLOSL-, ESHER, SURREY. KT109JR Telephofic; Esher (0372) 62071

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 3through 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-3210."
'The contents ol this nianuol are subject to change without notice.
SHINSHU SEIKI CO LTD
"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 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 2-34
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 3-15
3.4.2 Troubleshooting by symptom 3-1 6
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
ir SIMPLE TROUBLESHOOTING
6.1 General 6-1
6.2 Troubleshooting 6-1
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$
Fig. 1.1
Fig. 1.2
Fig. 1.3
Fig. 1.4
2.1
2.2
.2.3
. 2.4
. 2.5
. 2.6
.2.7
. 2.8
. 2.9
LIST OF FIGURES
CHAPTER 1
GENERAL
1-3
M-3210 Printer Mechanism
Main and Driver Circuit Boards
1-4
Power Supply Circuit
Upper and Lower Cases
CHAPTER 2
PRINCIPLES OF OPERATION
Flow of Signals
Component Layout of Fuse & Filter Circuit.
Connection Diagram of Fuse & Filter Circuit —
Windings of Transformer
Rectifier and Constant-Voltage Circuit
Flow of Data and Signals through 8155
8155 and Peripheral Circuits
Data Transfer Sequence ^^
Carriage Stepper Motor Drive Signals (Forward)
2-1
2-9
2-9
2-10
2-10
2-12
2-12
2-13
2.10 Paper Feed Stepper Motor Drive Signals.
2-14
2-15
g. 2.11 8041 and Peripheral Circuits
2.1 2 Signal ALE
2.13 8049 and Program Memory Circuits
g. 2.1 4 Locations of DIP Switches
g. 2.15 DIP Switch Status Read Circuit
g. 2.16 Reset (HP Sensor) Circuit 2-18
3. 2.17 Timing (PTS) Sensor Circuit
g. 2.18 Timing and Reset Detection Signals
g. 2.19 Driver Circuit
2.20 Current Waveform of Print Head
2.21 Applied Voltage vs. Driving Pulse Width
2.22 Switches and Indicators on control Panel.
2.23 Switch and Indicator Control Circuit
g. 2.24 Operation of Print Head
2-16
2-17
2-17
2-19
2-19
2-20
2-20
2-21
2-22
2-23
RE

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. 3.1 2 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
CHAPTER 4
MAINTENANCE
Fig. 4.1 Lube Points and Bonding Points 4-3
Fig. 4.2 Applied Voltage vs. Driving Pulse Width 4-4
Fig. 4.3 Timing Signal PTS (Pin No.39 of 8049) 4-5
Fig. 4.4 Relationship between Timing Signal and Signal PRAV 4-5
Fig. 4.5 Adjustment of PTS Sensor Board 4-6
Fig. 4.6 Relationship between Timing Signal and Reset Signal 4-6
Fig. 4.7 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
RFW A

LIST OF TABLES
CHAPTER 2
PRINCIPLES OF OPERATION
Table 2.1 Pin Assignment of ONI 2-2
Table 2.1 Pin Assignment of CN1 (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
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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
RFV. A

1.1 Features of MX-80
1.1 rcaiuic<» w. --
•oi matrix nrinter featuring 80 CPS bi-directional printing with logical
The MX-80 fformation, and is a fruit of our constant
seeking capability and 9 9 dot performance. The Printer is thus
.„„„S ,n pu...« 01
rrr»or.:;rrinr.zT..rir;r^d..,.
MX-80,
1.2 Features of Interfaces
::: L^n^ar" nt:rS::hrMx°8Tcirbe':^
for data communication. th^ My fin has the following interface options which
pef^t'me Ir^cTntct'^ to almost all the computers equipped with various
interfaces.
level prescribed for serial interfaces by the EIA
Printer to receive data at a bit rate ranging from 75 to 9.600 BPS.
H; =h: r=
ated into the computer
(4) TRS-80 Interface
TRS-80 Interface system of a TRS-80 computer manufac-
This optional interface is connected to the bus system oi a i o ^
tured by the Tandy Radio Shack, to permit printing of the TRS-80 programs
data on 'he MX^8a .o^figured to cope with various interfaces. For further
ir.rrr:."r «... ™™.i —
published for each interface.
1.3 Serviceability
The MX-80 has been designed to minimize maintenance and repair in operation under its
Should maintenance or Scents can be
S^reasi?'rcrir;"Lrer,sU" it^ to penorm minimum maintenance and
repair with ease by referring to this manual.
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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 9x9 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 (0 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 I2.0"x 4 2")
(15) MTBF 5 X10'Mines (excluding print head)
(16) Print Head Life 100 x 10" 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 H2