OKIDATA ML393Plus User manual

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Page: 1
Service Guide ML393/ML393CPlus
Chapter 0 About This Manual
ML393Plus // ML393C Plus
Dot Matrix Printers
Adobe Acrobat printable reference
copy of the OKIDATA Service Training Manual.
09/17/97
Note: This Adobe Acrobat version of the Okidata Service Training Manual was built with the
pictures rendered at 300 dpi, which is ideal for printing, but does not view on most
displays well.
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

Table of Contents Page
Service Guide ML393/ML393CPlus
0 About This Manual
Front Cover 1
Copyright 2
1 Specifications
1.1 Overview - General Information/Specifications 3
1.2 Physical Specifications 4
1.3 Power Requirements 5
1.4 Environmental Conditions 6
1.5 Agency Approvals 7
1.6 Operational Specifications - Character Matrix Sizes 8
....1.6.02 Characters Per Line 9
....1.6.03 Character Pitches 10
....1.6.04 Character Sets 11
....1.6.05 Emulations 12
....1.6.06 Fonts 13
....1.6.07 Front Panel Switches 14
....1.6.08 Graphics Resolution 15
....1.6.09 Interface 16
....1.6.10 Line Feed Increments 17
....1.6.11 Line Feed Time 18
....1.6.12 Menu Mode 19
....1.6.13 Paper Feed Methods 20
....1.6.14 Paper Feed Paths 21
....1.6.15 Paper Loading 22
....1.6.16 Paper Out Detection 23
....1.6.17 Paper Tear Capabilities 24
....1.6.18 Print Method 25
....1.6.19 Print Modes 26
....1.6.20 Print Speed 27
1.7 Paper Specifications 28
1.8 Memory Specifications 29
1.9 Consumables 30
1.10 Options 31
1.11 Reliability 32
2 Principles of Operation
2.1 Principles of Operation - General Information 33
....2.1.02 Microprocessors (MPUs) and Peripheral Circuits 34
....2.1.03 Initialization 35
....2.1.04 Interface Control 36
....2.1.05 Printhead Drive Circuit 37
....2.1.06 Spacing Drive Circuit 38
....2.1.07 Line Feed Circuit 39

Table of Contents Page
....2.1.08 Alarm Circuits 40
....2.1.09 Paper End Detection Circuit 41
....2.1.10 Power Supply 42
2.2 Mechanical Operation - Printhead Mechanism 43
....2.2.02 Spacing 44
....2.2.03 Ribbon Drive 45
....2.2.04 Paper Feed 46
....2.2.05 Paper-End Detection 47
....2.2.06 Paper Park 48
....2.2.07 Automatic Paper Loading 49
3 Maintenance
3.1 Maintenance - General Information 50
3.2 Disassembly/Assembly Procedures - General Information 51
....3.2.01 Preliminary Items, Printhead 52
....3.2.02 Ribbon Guide 53
....3.2.03 Ribbon Protector 54
....3.2.04 Upper Cover Assembly 55
........Parts List 56
....3.2.05 Operator Panel Assembly 57
....3.2.06 Control Board (LQEM) 58
....3.2.07 Interface Connector Board (LQPN) 59
....3.2.08 Printer Mechanism 60
....3.2.09 Platen Assembly 61
....3.2.10 Line Feed Motor 62
....3.2.11 Printhead Cable Assembly 63
....3.2.12 Sensor Board 64
....3.2.13 Ribbon Feed Assembly 65
....3.2.14 Space Motor Assembly 66
....3.2.15 Space Belt 67
....3.2.16 Bail/Ribbon Motor Assembly 68
....3.2.17 Paper Bail Assembly 69
....3.2.18 Carriage and Carriage Shaft 70
........Parts List 71
....3.2.19 Paper Pressure Guide 72
....3.2.20 Printhead Gap / Release Lever Microswitches 73
....3.2.21 Push Tractor Assembly 74
........Procedure - Installation Notes 75
....3.2.22 Power Supply Unit 76
....Microline 393C-Plus - Color Model Only : Sections 3.2.23
through 3.2.28 77
........3.2.23 Ribbon Shift Arm Spring / Ribbon Shift Arm :
Microline 393C-Plus - Color Model Only 78
........3.2.24 Roller Lever : Microline 393C-Plus - Color Model
Only 79

Table of Contents Page
........3.2.25 Ribbon Guide : Microline 393C-Plus - Color Model
Only 80
........3.2.26 Bail Open Cam and Bail Open Gear : Microline
393C-Plus - Color Model Only 81
........3.2.27 Ribbon Shift Cam and Ribbon Shift Gear :
Microline 393C-Plus - Color Model Only 82
........3.2.28 Ribbon Shift Cam Lever Assembly : Microline
393C-Plus - Color Model Only 83
....Cut Sheet Feeder - Option : Sections 3.2.29 Through 3.2.35 84
........3.2.29 Friction Sheet 85
........3.2.30 Rear Bin 86
........3.2.31 Side Cover 87
........3.2.32 Roller Supports and Rollers (H) 88
........3.2.33 Control Board 89
........3.2.34 Connection Cord 90
........3.2.35 Motor Assembly 91
3.3 Printer Adjustments - General Information 92
....3.3.02 Printhead Gap Adjustment 93
....3.3.03 Line Feed Belt Tension 94
....3.3.04 Color Adjustment (Microline 393C-Plus Printer) 95
....3.3.05 Key Combinations 96
....3.3.06 Menu Operation - General Information 97
........Menu Mode 98
........Menu Print 99
........Sample Menu 100
........Menu Settings 101
........Menu Reset 102
........Limited Operation 103
....3.3.07 Top of Form 104
....3.3.08 Paper Park 105
....3.3.09 Forms Tear Off 106
....3.3.10 Resets 107
3.4 Cleaning 108
3.5 Lubrication - General Information 109
....3.5.02 Lubrication Schedule 110
....3.5.03 Lubrication Types and Amounts 111
....3.5.04 Areas Not Lubricated 112
....Lubrication Points (Monochrome and Color) 113
....Platen, Carriage Shaft, Idle Gear 114
....Ribbon Feed Assembly 115
....Lubrication Points (Color) 116
....Lubrication Points (Options) 117
3.6 Shipping Instructions 118
4 Failure Analysis

Table of Contents Page
4.1 Overview 119
4.2 Reporting Problems 120
4.3 Troubleshooting Updates 121
4.4 Troubleshooting Tips - Preliminary Checks 122
....4.4.02 Problem Categories 123
....4.4.03 START HERE Flowchart 124
....4.4.04 Tips for Preventing Image Problems 125
....4.4.05 Common Problems 126
........Epson / IBM, Self Test Revision 1.16 (FCO 7681) 127
........Missing Spaces When Printing Wide Reports (FCO 7693) 128
........Self Test Revisions 1.07 and 1.10 (FCO 7730) 129
........Parallel Timing Specification Changes 130
........Jumper SP2 Added to Main Control Board 131
........Font Name Changes in Menu Mode 132
........Modifications to Q6, Main Control Board 133
4.5 Abnormal Output 134
4.6 Fault Alarms 135
4.7 Repair Analysis Procedures (RAPS) 136
....RAP 01: Power Lamp Does Not Light 137
....RAP 02: Space Error (ALARM 57) 138
....RAP 03: Head Homing Error (ALARM 53) 139
....RAP 04: Ribbon Homing Error (ALARM 5B) 140
....RAP 05: Bail Home Error (ALARM 5C) 141
....RAP 06: Wrong Character, Character Omission, or Dot
Omission 142
....RAP 07: Ribbon Feed Trouble 143
....RAP 08: Line Feed Trouble 144
....RAP 09: Malfunction of Operator Panel Switch 145
....RAP 10A: Data Receive Failure 146
....RAP 10B: Parallel Interface Problem 147
....RAP 10C: Serial Interface Problem 148
....RAP 10D: Data Receive Failure (Alarm Light Lit) 149
....RAP 11: Color Ribbon Shift Problem 150
4.8 Printer Tests - General Information 151
....4.8.02 Rolling ASCII Print Test 152
....4.8.03 Font Test 153
....4.8.04 Serial Interface - Loopback Test 154
....4.8.05 Hexadecimal Dump 155
4.9 Resistance Checks - General Information 156
....4.9.02 Printhead Resistance Check 157
....4.9.03 Line Feed Motor Resistance Check 158
....4.9.04 Space Motor Resistance Check 159
....4.9.05 Ribbon Motor Resistance Check 160
A Board Diagrams

Table of Contents Page
A.1 Overview - General Information 161
A.2 Index To Charts 162
....A.2.01 Main Control Board (LQEM) 163
....A.2.02 Power Supply 164
....A.2.03 Interface Board (LQPN) 165
....A.2.04 Sensor Board (LQEW or LPRW) 166
....A.2.05 Operator Panel Board (LQSX) 167
B Illustrated Parts Listing
B.1 Overview - General Information 168
....B.1.02 Definition of Terms 169
....B.1.03 Parts Ordering Information 170
B.2 Charts 171
....B.2.01 Printer Unit 172
....B.2.02 Upper Cover Assembly 173
....B.2.03 Printer Unit General Assembly (1 of 2) 174
....B.2.04 Printer Unit General Assembly (2 of 2) 175
....B.2.05 Operator Panel Assembly 176
....B.2.06 Printer Mechanism - Monochrome (1 of 3) 177
....B.2.07 Printer Mechanism - Monochrome (2 of 3) 178
....B.2.08 Printer Mechanism - Monochrome (3 of 3) 179
....B.2.09 Printer Mechanism - Color (1 of 3) 180
....B.2.10 Printer Mechanism - Color (2 of 3) 181
....B.2.11 Printer Mechanism - Color (3 of 3) 182
....B.2.12 Carriage Assembly - Monochrome 183
....B.2.13 Carriage Assembly - Color 184
....B.2.14 Options 185
....B.2.15 Pull Tractor Assembly (Option) 186
....B.2.16 Packing Materials 187
....B.2.17 Consumables 188
....B.2.18 Documentation 189
....B.2.19 Service Training Kit Revision List 190
C Microline 393/393C Specifications
C.1 Overview - General Information 191
C.2 Printer Specifications 192
C.3 Paper Specifications 193
C.4 Physical Specifications 194
C.5 Power Requirements 195
C.6 Environmental Conditions 196
C.7 Agency Approvals 197
C.8 Options 198
C.9 Consumables 199
C.10 Memory Specifications 200
C.11 Printer Reliability 201

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Service Guide ML393/ML393CPlus
Chapter 0 About This Manual
Microline 393 / 393C-Plus Service Handbook
This document may not be reproduced without the written permission of the Okidata Technical Training
Group. Every effort has been made to ensure the accuracy of the information contained in this training
course. Okidata is not responsible for errors beyond its control.
©1995 by Okidata All rights reserved.
First Edition April 1990P/N 59241601
Second Edition February 1995P/N 59241602
Written and produced by the Okidata Sales and Product Training
Please address any comments on this publication to:
Sales and Product Training
Okidata
532 Fellowship Road
Mount Laurel, NJ 08054-3499
Fax Number: [phone]
Okilink Login Name: Technical Training
OKIDATA is a registered trademark of Oki Electric Industry Company, Ltd.; marques deposee de Oki
Electric Industry Company, Ltd.; marca registrada, Oki Electric Industry Company, Ltd.
MICROLINE is a registered trademark of Oki Electric Industry Company, Ltd.; marque depose de Oki
Electric Industry Company, Ltd.
Centronics is a registered trademark of Centronics Inc.
PLUG 'n PRINT is a registered trademark of Oki America, Inc.; marque deposee de Oki America, Inc.
Epson is a registered trademark of Seiko Epson Corporation.
IBM, Proprinter and Proprinter XL are registered trademarks of International Business Machines, Inc.
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

Page: 3
Service Guide ML393/ML393CPlus
Chapter 1 Specifications
1.1 OVERVIEW
1.1.01 General Information
The Microline 393-Plus and Microline 393C-Plus are high speed, dot matrix printers, which utilize a 24 pin
printhead.
The Microline 393-Plus is the standard version (monochrome).
The Microline 393C-Plus is the color capable version.
The printers are capable of emulating the Epson LQ-2550 and the IBM Proprinter XL24 printers.
Both an RS232-C Serial Interface and a Centronics Parallel Interface are standard.
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

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Service Guide ML393/ML393CPlus
Chapter 1 Specifications
1.2 PHYSICAL SPECIFICATIONS
1.2.01 Dimensions
NOTE: Dimensions INCLUDE the platen knob, acoustic cover, and paper separator.
Width: 25.2 inches (54 centimeters)
Depth: 19 inches (48.3 centimeters)
Height: 8 inches (20.3 centimeters)
1.2.02 Printer Weight
37 pounds (16.8 kilograms)
UPS Shippable
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

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Service Guide ML393/ML393CPlus
Chapter 1 Specifications
1.3 POWER REQUIREMENTS
1.3.01 Input Power
120 VAC: +10 / -15%
220 VAC: +10 / -15%
1.3.02 Power Consumption
Operating: 180 VA
Idle: 50 VA
1.3.03 Power Frequency
50/60 Hz +/- 2%
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

Page: 6
Service Guide ML393/ML393CPlus
Chapter 1 Specifications
1.4 ENVIRONMENTAL CONDITIONS
1.4.01 Acoustic Rating
Letter Quality Mode
58 dBA
Quiet Mode
54 dBA
1.4.02 Altitude
10,000 feet (3,048 meters)
1.4.03 Ambient Temperature and Relative Humidity (RH)
While operating: 41 to 104 degrees Fahrenheit (5 to 40 degrees Celsius)
Operating humidity: 20% to 90% RH
While in storage: -40 to 158 degrees Fahrenheit ( - 40 to 70 degrees Celsius)
Storage humidity: 5% to 95% RH
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

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Service Guide ML393/ML393CPlus
Chapter 1 Specifications
1.5 AGENCY APPROVALS
1.5.01 Listings
UL No: UL Standard No. 478
CSA No: CSA Standard C22.2 (220)
FCC: FCC Class B
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

Page: 8
Service Guide ML393/ML393CPlus
Chapter 1 Specifications
1.6 OPERATIONAL SPECIFICATIONS
1.6.01 Character Matrix Sizes
Table of Print Speed and Character Matrix
Mode Speed Matrix (Horizontal x Vertical) @ cpi
Letter Quality 140 cps 30 x 18 @ 12 cpi
Near Letter Quality 210 cps 15 x 18 @ 12 cpi
Utility 415 cps 9 x 17 @ 12 cpi
High Speed Draft 520 cps 7 x 17 @ 15 cpi
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

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Service Guide ML393/ML393CPlus
Chapter 1 Specifications
1.6.02 Characters Per Line
Characters Per Line Characters Per Inch (Maximum)
136 10
163 12
204 15
233 17.1
272 20
PS -
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

Page: 10
Service Guide ML393/ML393CPlus
Chapter 1 Specifications
1.6.03 Character Pitches
10, 12, 15, 17.1, 20
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

Page: 11
Service Guide ML393/ML393CPlus
Chapter 1 Specifications
1.6.04 Character Sets
Standard ASCII
EPSON Character Set I & II
IBM Character Set I, II & All Characters
16 Foreign Language Sets
Zero / Slashed Zero
DLL - 2 Sets of 128 characters
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

Page: 12
Service Guide ML393/ML393CPlus
Chapter 1 Specifications
1.6.05 Emulations
NOTE: The emulations are co-resident
Epson LQ
IBM XL24
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

Page: 13
Service Guide ML393/ML393CPlus
Chapter 1 Specifications
1.6.06 Fonts
Standard
Courier
Swiss
Roman
Orator
Optional Font Cartridges
Prestige
Letter Gothic
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

Page: 14
Service Guide ML393/ML393CPlus
Chapter 1 Specifications
1.6.07 Front Panel Switches
SELECT Paper Park / Top of Form
Quiet (Menu) Mode Font Selection
Line Feed Pitch Selection
FORM FEED Print Quality Selection
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)