Oki ML380 SERVICE MANUAL

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Service Guide ML380

Chapter 0 About This Manual

ML380

Dot Matrix Printer

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.

Table of Contents Page

Service Guide ML380

0 About This Manual

Front Cover 1 Manual Copyright 2

1 Product Specifications

1.1 Overview 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 8

1.7 Paper Specifications 9

1.8 Memory Specifications 10

1.9 Consumables 11

1.10 Options 12

1.11 Reliability 13

2 Principles of Operation

2.1 Principles of Operation - General Information 14

....2.1.02 Microprocessor and Peripheral Circuits 15

....2.1.03 Initialization 16

....2.1.04 Interface Control 17

....2.1.05 Printhead Drive Circuit 18

....2.1.06 Spacing Drive Circuit 19

....2.1.07 Line Feed Circuit 20

....2.1.08 Alarm Circuits 21

....2.1.09 Paper End Detection Circuit 22

....2.1.10 Power Supply 23

2.2 Mechanical Operation - Printhead Mechanism 24

....2.2.02 Spacing 25

....2.2.03 Ribbon Drive 26

....2.2.04 Paper Feed 27

....2.2.05 Paper-End Detection 28

....2.2.06 Semi-Automatic Sheet Feeder (SASF) 29

....2.2.07 Paper Park 30

3 Maintenance & Disassembly

3.1 Maintenance - General Information 31

....3.1.02 Maintenance Tools 32

....3.1.03 Maintenance Precautions 33

3.2 Disassembly/Assembly Procedures - General Information 34

....3.2.01 Paper Separator 35

....3.2.02 Printhead 36

....3.2.03 Upper Cover Assembly 37

....3.2.04 Space Rack 38

Table of Contents Page

....3.2.05 Ribbon Feed Gear Assembly 39

....3.2.06 Mini-Pitch (Space) Belt 40

....3.2.07 Head Connector Assembly 41

....3.2.08 Main Control Board (UMMB) 42

....3.2.09 Operation Panel 43

....3.2.10 Line Feed Motor 44

....3.2.11 Photosensor Assembly (Paper End) 45

....3.2.12 Bail Arms 46

....3.2.13 Carriage Frame 47

....3.2.14 Platen Assembly 48

....3.2.15 Pressure Roller Assembly 49

....3.2.16 Paper Pressure Guide 50

....3.2.17 Tractor Assembly 51

....3.2.18 Microswitch Assembly (SASF) 52

....3.2.19 Microswitch Assembly (Home Position Switch) 53

....3.2.20 Printer Mechanism 54

....3.2.21 Power Supply Unit 55

....3.2.22 Space Motor Assembly 56

....3.2.23 Bottom Paper Guide Lever 57

3.3 Printer Adjustments 58

....3.3.02 Gap Between Platen and Printhead 59

....3.3.03 Space Belt Tension 60

....3.3.04 Key Combinations 61

....3.3.05 Menu Operation / Menu Select Mode - General

Information

........From Print Mode 63

........From Power-OFF 64

........Printing the Menu 65

........Sample Menu 66

........Reset Menu to Factory Defaults 67

........Limited Operation 68

........Menu Settings 69

....3.3.06 Top of Form 70

....3.3.07 Paper Park 71

....3.3.08 Paper Tear Off 72

....3.3.09 Resets 73

3.4 Cleaning 74

3.5 Lubrication 75

3.6 Shipping Instructions 76

4 Failure & Repair Analysis

4.1 Failure & Repair Analysis - Introduction 77

....4.1.02 Printer Serial Number Identification 78

....4.1.03 Firmware Revision Identification 79

4.2 Reporting Problems - General Information 80

Table of Contents Page

....4.2.02 Problem Lists 81

....4.2.03 Reporting Methods 82

4.3 Troubleshooting Updates General Information 83

4.4 Troubleshooting Tips 84

....4.4.02 Problem Categories 85

....4.4.03 START HERE Flowchart 86

....4.4.04 Tips for Preventing Image Problems 87

....4.4.05 Common Problems 88

4.5 Abnormal Output 89

4.6 Fault Alarms - General Information 90

....4.6.02 Fault Alarm Lamp Display 91

4.7 Repair Analysis Procedures (RAPS) - Using The RAPS 92

....4.7.02 RAP Index 93

........RAP 01: No Power 94

........RAP 02: Space Operation Does Not Operate Normally 95

........RAP 03: Wrong Character or Missing Dots 96

........RAP 04: Line Feed Trouble 97

........RAP 05: Data Receiving Failure 98

4.8 Printer Tests - General Information 99

....4.8.02 Rolling ASCII Test 100

....4.8.03 Font Test 101

....4.8.04 Serial Interface Loopback Test - General Information 102

........Loopback Connector Configuration Diagram 103

........Procedure 104

........Serial Cable Information 105

........Serial Interface Signal Requirements 106

........Commonly Used Serial Cable Configurations 107

....4.8.05 Hexadecimal Dump Mode 108

4.9 Resistance Checks - General Information 109

....4.9.02 Main Control Board (UMMB) Voltage Check Points 110

....4.9.03 Connectors Block Diagram 111

....4.9.04 Connector Location 112

....4.9.05 Resistance Diagrams - Printhead 113

........Space and Line Feed Motors 114

....4.9.06 Head Cable Connection 115

A Board Diagrams

A1 Board Diagrams - General Information 116 A.2 Index To Charts 117

....A.2.01 Main Control Board (UMMB) Original 118

....A.2.02 Main Control Board (UMMB) Current 119

....A.2.03 RS232-C Serial Module (UMRS) 120

B Illustrated Parts Listing

B.1 Overview - General Information 121

....B.1.02 Definition of Terms 122

Table of Contents Page

....B.1.03 Parts Ordering Information 123

B.2 Charts 124

....B.2.01 Printer 125

....B.2.02 Covers 126

....B.2.03 Printer Unit 127

....B.2.04 Printer Mechanism (1 of 3) 128

....B.2.05 Printer Mechanism (2 of 3) 129

....B.2.06 Printer Mechanism (3 of 3) 130

....B.2.07 Option Parts 131

....B.2.08 Consumables 132

....B.2.09 Packaging 133

....B2.10 Documentation 134

....B.2.11 Service Training Kit Revision List 135

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Service Guide ML380

Chapter 0 About This Manual

Manual Copyright

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.

© 1994 by Okidata All rights reserved. First Edition August, 1989 P/N 59238701 Second Edition September, 1993 P/N 59238702 Third Edition November, 1994 P/N 59238703 Written and produced by the Okidata Technical Training Group Please address any comments on this publication to: Technical Training Group

Okidata 532 Fellowship Road Mount Laurel, NJ 08054-3499 Fax Number: (609) 235-2600, ext. 7034

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 is a registered trademark of International Business Machine Corporation.

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Service Guide ML380

Chapter 1 Product Specifications

1.1 OVERVIEW

1.1.01 General Information

The Microline 380 is an 80 column, impact dot matrix printer using a 24 pin printhead. It emulates the Epson LQ printer.

A push tractor is standard. An optional pull tractor is available. Font and Character Pitch selection is available through the operator panel, printer menu, or through

software (using control codes). A Centronics Parallel interface is standard. An RS232-C serial module is available as an option.

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Service Guide ML380

Chapter 1 Product Specifications

1.2 PHYSICAL SPECIFICATIONS

1.2.01 Dimensions

Width: 15.67 inches (398 millimeters) Depth: 4.72 inches (120 millimeters) Height: 13.58 inches (345 millimeters)

NOTE: Dimensions DO NOT INCLUDE the platen knob, acoustic cover, and paper separator.

1.2.02 Weight

17.9 pounds (8.1 kilograms)

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Service Guide ML380

Chapter 1 Product Specifications

1.3 POWER REQUIREMENTS

1.3.01 Input Power

120 VAC: +5.5 / -15% 220/240 VAC: +5.5 / -15% Single-phase AC

1.3.02 Power Consumption

Operating: 90 VA Idle: 30 VA

1.3.03 Power Frequency

120 VAC: 50/60 Hz +/- 2% 220/240 VAC: 50/60 Hz +/- 2%

Service Guide ML380

Chapter 1 Product Specifications

1.4 ENVIRONMENTAL CONDITIONS

1.4.01 Acoustic Rating

57 dBA

1.4.02 Altitude

10,000 feet (3,050 meters)

1.4.03 Ambient Temperature and Relative Humidity (RH)

While operating: 41 to 95 degrees Fahrenheit (5 to 35 degrees Celsius) Operating humidity: 20% to 80% RH While in storage: -40 to 158 degrees Fahrenheit (-40 to 70 degrees Celsius) Storage humidity: 5% to 95% RH

1.4.04 Impact

Non-operating: 3 G or less

1.4.05 Vibration

Operating: 0.3 G (5 to 150 Hz) or less (except at resonating frequency) Non-Operating: 1 G (5 to 150 Hz) or less (except at resonating frequency)

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Service Guide ML380

Chapter 1 Product Specifications

1.5 AGENCY APPROVALS

1.5.01 Listings

UL No: UL Standard No. 478 and 114 CSA No: CSA Standard C22.2 No. 154 FCC: FCC Certified per Part 15, Subject J, Class B VDE: VDE 0806, 0875 Class B, and 0836 BS: BS 5850 / 6204 IEC: 435 / 380

1.6 OPERATIONAL SPECIFICATIONS

1.6.01 Character Matrix Sizes Table of Print Speed and Character Matrix

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Service Guide ML380

Chapter 1 Product Specifications

Mode

Speed 63 cps (12 cpi) 192 cps (12 cpi) 240 cps (15 cpi) Matrix (H x V) 30 x 18 9 x 17 7 x 16

1.6.02 Characters Per Line

Maximum Characters Per Line

80 10 96 12 120 15 137 17.1 160 20

1.6.03 Character Pitches

5, 6, 8.5, 10, 12, 15, 17.1, 20 characters per inch Characters Per Inch = cpi The character pitches are selected through the following methods. Operator panel (front panel controls) Menu Select Mode (Menu Mode) Control codes in the software Special Microline 380 drivers

LQ Utility HS Utility

Characters Per Inch

1.6.04 Character Sets

Standard ASCII EPSON Character Set IBM Character Set I and II Foreign Language Sets (14) Line Graphics Zero / Slashed Zero

1.6.05 Emulation

Epson LQ

1.6.06 Fonts

Letter Quality

Courier Letter Gothic Prestige Orator Roman Helvette

Draft

Utility

Special Font Effects

Emphasized / Enhanced Outline Shadow Double Height Double Width

1.6.07 Front Panel Switches

SELECT / Exit FEED / Group TOF / PARK / Item FONT / Set PITCH / Print

1.6.08 Graphics Resolution

Graphics Resolution Maximum: 180 x 360 dpi Minimum: 60 x 72 dpi

*1.6.09 Interface

Standard

Parallel

Optional

RS232C Serial, 19.2 Kbytes Super-Speed (Ready/Busy, X-ON / X-OFF)

NOTE: When the serial interface module is installed, the printer's parallel interface connector is NOT accessible.

1.6.10 Line Feed Increments Fixed

6 lines per inch (lpi) [0.167 inch (4.23 millimeters)] 8 lines per inch (lpi) [0.125 inch (3.175 millimeters)]

Variable

n/60 inch n/180 inch

1.6.11 Line Feed Time

2.2 inches per second

1.6.12 Menu Mode

Print: Prints the entire menu. Group: Selects Group Function Item: Selects Item Set: Selects Item Value Exit: Exits Menu Mode, Enters Select

1.6.13 Paper Feed Methods

Standard

Friction Feed (Top) Push Tractor (Rear)

Optional

Pull Tractor (Bottom / Rear) Single-Bin Cut Sheet Feeder (Top) CSF 3800

1.6.14 Paper Feed Paths

Top Feed (Standard) Rear Feed (Standard) Bottom Feed (by using an Optional feed mechanism) Special Features Paper Park Semi-Automatic Sheet Feeding Paper Tear Off

1.6.15 Paper Loading

Semi-Automatic Sheet Feeding Opening the paper bail arm activates the semi-automatic sheet feeder (SASF)

1.6.16 Paper Out Detection

Distance from end of paper Rear Feed: 2.3 inches (57 millimeters) Bottom Feed: 1.4 inches (36 millimeters) Top Feed: 1 inch (25 mm)

1.6.17 Paper Tear Capabilities

Paper Tear-0ff (sharp edge on access cover)

1.6.18 Print Method Printhead Type General Information

Impact Dot Matrix 24 pin printhead .0079 inch (.20 millimeter) diameter pins

Overheat Protection

When printhead temperature is between 90 and 129 degrees Celsius (ALARM 1), the printer stops

bi-directional printing. Uni-directional printing begins. If the temperature continues to rise (130 degrees Celsius, ALARM 2), printing stops. Printing will resume when the printhead temperature drops below the ALARM 1 threshold.

NOTE: Refer to Section Two for more information on printhead operation.

Printhead Gap Information

Two items factor into printhead gap information.

1. Printhead Gap This is a SERVICE ADJUSTMENT made by a technician. It is covered in Section 3.3 of this Service Handbook. The Adjustment measures 0.016, +/- 0.002 inches (0.41, +/- 0.05 mm).

2. Printhead Gap The printhead gap is modified by moving the printhead gap lever, located on the left side of the housing. To move the lever, pull it towards the printer housing and push the lever towards the front of the printer. The settings are 1, 2, 3, 4, and 5. Use 1 for single sheet.

Adjustment

Adjust

Use 2 for multiple sheets or forms (thickness: 2 sheets). Use 3 for multiple sheets or forms (thickness: 3 sheets). Use 4 for multiple sheets or forms (thickness: 4 sheets). Use 5 for envelopes and extra thick paper.

1.6.19 Print Modes

Letter Quality Utility

1.6.20 Print Speed

Print Mode

LQ 50 cps 60 cps 75 cps 85 cps 100 cps Utility 150 cps 180 cps 112.5 cps 128.25 cps 150 cps

Character Pitch

10 cpi 12 cpi 15 cpi 17.1 cpi 20 cpi

1.7 PAPER SPECIFICATIONS

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Service Guide ML380

Chapter 1 Product Specifications

CAUTION:

1.7.01 Types Card Stock

Length: 3 to 14 inches (76.2 to 356 millimeters) Number of Copies: Original Paper Feed Path: Bottom Printhead Gap Information: Refer to the Printhead Gap Information, Section 1.6 Thickness: .008 inches (0.2 millimeters) Maximum Weight: 100 lbs. (375 g/m 2 ) Maximum Width: 5 to 8 inches (127 to 203 millimeters)

Continuous Form

Length: 3 to 14 inches (76.2 to 356 millimeters) Number of Copies: Original, Original + 2 Interleaf Original + 2 Carbonless Paper Feed Path: Rear or Bottom Printhead Gap Information: Refer to the Printhead Gap Information, Section 1.6 Thickness: Single 0.0028 to 0.0039 inches (0.07 to 0.1 millimeters) Multi 0.01 inch (.25 millimeter) Maximum Weight: Single Part 14 - 22 lb. (52.5 to 82.5 to g/m 2 ) Multi-Part, Carbonless 9 - 11 lb. (35 to 40 g/m 2 ) Multi-Part, Interleaf Paper 10 - 12 lb. (38 to 45 g/m 2 ) Carbon 9 lb. (35 g/m 2 ) Width: 3.5 to 10.5 inches (89 to 267 millimeters)

Cut Sheet

Number of Copies: Original, Original + 2 Interleaf Original + 2 Carbonless Paper Feed Path: Top Printhead Gap Information: Refer to the Printhead Gap Information, Section 1.6. Note: Multi-part cut sheet paper CANNOT be used. Weight: 14 to 22 lbs. (52.5 to 82.5 g/m 2 ) Width: 7.2 to 10 inches (182 to 254 millimeters) Length: 3 to 14 inches (76.2 to 356 millimeters) Thickness: 0.0028 to 0.0039 inches (0.07 to 0.1 millimeters)

Envelopes

Number of Copies: Original Paper Feed Path: Bottom Printhead Gap Information: Refer to the Printhead Gap Information, Section 1.6. Size: Single Feed Minimum: 6.5 x 3.6 inches (16.5 x 9.1 centimeters) Maximum: 9.5 x 4.1 inches (24.1 x 10.4 centimeters) Continuous Non-overlap type Thickness: .016 inches (41 millimeters) Maximum Weight: 17 to 24 lbs. (64 to 90 g/m 2 ) Maximum

Labels

Length: 3 to 14 inches (76.2 to 356 millimeters)

Use Bottom Feed and/or optional Pull Tractor for card stock and labels.

Number of Copies: Original Paper Feed Path: Bottom Printhead Gap Information: Refer to the Printhead Gap Information, Section 1.6. Weight: N/A Width: Carrier 3.5 to 8.5 inches (88 to 261 millimeters) Thickness: .01 inches (0.25 mm) Maximum (including backing)

CAUTION:

Use Bottom Feed and/or optional Pull Tractor for card stock and labels. DO NOT use fabric labels. DO NOT print on the edge or perforation of the label. DO NOT use Paper Park with labels.

Transparency

NOTE: Roller marks may mar the transparency under high temperature / high humidity conditions.

Length: 3 to 14 inches (76.2 to 356 millimeters) Number of Copies: Original Paper Feed Path: Top Printhead Gap Information: Refer to the Printhead Gap Information, Section 1.6. Weight: 12 to 24 lbs. (45 to 90 g/m 2 ) Width: 8.5 to 11 inches (216 to 280 millimeters) Thickness: 0.004 inches (0.1 millimeters)

1.8 MEMORY SPECIFICATIONS

1.8.01 EEPROM

256 Kbit EEPROM Used to store Menu data Located at Q18 of the main control board

1.8.02 ROM

Program ROM 256 Kbit Located at Q2 of the main control board Resident Character Generator ROM 1 Mbit Masked to the CPU

1.8.03 RAM

32 Kbyte Located on the main control board Used as Receive Buffer Printer Buffer Scratch Pad

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Service Guide ML380

Chapter 1 Product Specifications

1.9 CONSUMABLES

1.9.01 Ribbon

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Service Guide ML380

Chapter 1 Product Specifications

CAUTION:

Material Cartridge Fabric

Types Black Nylon Ribbon Life (On average, at 10 characters per inch, Utility Mode) Black Ribbon 2 million characters

Using a non-Okidata ribbon may damage the printhead and void any warranties.

1.10 OPTIONS

1.10.01 Cut Sheet Feeders

CSF-3800 Single Bin with envelope capability Paper Width: 7.2 to 8.5 inches 182 to 216 millimeters Paper Length: 10.1 to 11.7 inches 257 to 297 millimeters Capacity: 50 sheets (20 lb.)

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Service Guide ML380

Chapter 1 Product Specifications

1.10.02 Pull Tractor Kit

Bottom Feed Rear Feed (For Push/Pull Operation) Paper Types: Continuous Feed and Labels

1.10.03 Serial Interface

Super-Speed 19.2K RS-232C Ready/Busy/X-On/X-Off Protocols Can be configured through the Menu When the serial interface module is installed, the printers parallel interface connector is NOT accessible.

Service Guide ML380

Chapter 1 Product Specifications

1.11 RELIABILITY

1.11.01 Mean Time Before Failure (MTBF)

Approximately 4,000 hours: 25% duty cycle / 35% page density

1.11.02 Mean Time To Repair (MTTR)

Approximately 15 minutes to major sub-assembly level

1.11.03 Printer Life

Approximately 12,000 hours of power-on time: 25% duty cycle / 35% page density

1.11.04 Printhead Life

Average 200 million characters in 10 cpi utility mode @ normal 25% duty, 35% page density

1.11.05 Ribbon Life

Approximately 2 million characters in 10 cpi mode

1.11.06 Warranty (Limited)

One year, parts, labor, and printhead

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1.11.07 Service

Authorized Okidata Service Centers

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Service Guide ML380

Chapter 2 Principles of Operation

2.1 ELECTRICAL OPERATION

2.1.01 General Information

The control board consists of the microprocessor and its peripheral circuits, the drive circuits, DC power supply circuit and interface connector. The switches and LED's of the operator panel are mounted on this board.

The power to the control board is supplied by the power supply unit. The power to the other electrical parts is distributed via the connectors on the control board.

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Service Guide ML380

Chapter 2 Principles of Operation

2.1.02 Microprocessor and Peripheral Circuits

Microprocessor (Q5: 83C154GS-551-V1K)

The microprocessor is the nucleus of the control circuit. Its peripheral circuits operate under program control by this microprocessor. The I/O ports of the microprocessor are connected to the address bus, data bus, and control lines.

Program ROM (Q2)

The program ROM (256 Kbit) contains the control program for the printer. The microprocessor operates by execution of this program.

RAM (Q4)

The RAM stores received data (to be printed). (32 Kbytes)

CGROM (Q3)

1 MBit ROM which stores the resident character fonts.

EEPROM (Q18)

This 256-bit serial Electrically Erasable and Programmable ROM stores the Menu Mode data.

LSI (Q7: LC92018B-283)

This LSI switches the phase of the space motor, and generates the timing of print dots for each print density. The LSI performs the following functions.

Space Pulse Motor Control

To obtain the carriage speed instructed by the microprocessor, the LSI generates the pulse switch timing and overdrive time.

Dot Timing generation Parallel Interface Control LF Motor Control LED Drive General Purpose Input Port Used to read Operator Board Switches.

LSI (Q6: LC92011B-284)

This LSI drives the 24 pin printhead and controls memory. The following describes the function of the LSI.

Printhead Drive Control

Head Pin Counting Function Counts the number of printwires to be driven then, changes the duration of the HD ON signal accordingly.

Memory Control

Extends the addressable memory by switching banks in/out. LED Drive Output Port

Microline 380 Block Diagram

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Service Guide ML380

Chapter 2 Principles of Operation

2.1.03 Initialization

The printer is initialized whenever it is powered ON or when the I-PRIME signal is received at the parallel interface. Initialization is started when the RST-P signal is sent from the reset circuit (Q8:Pin 1) to Q5, Q6 and Q7.

When RST-P is generated, ROM program execution starts with the mode setting of Q5, Q6 and Q7. Next, ROM and RAM are checked for errors, RAM is initialized and the carriage is homed. The program finally establishes the Interface signals (output level of ACK, BUSY, etc.), switches the SELECT indicator ON, and informs the host computer that the printer is ready to receive data.

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Service Guide ML380

Chapter 2 Principles of Operation

2.1.04 Interface Control

Parallel Interface

The data from the interface is received through connector (CN-1) and the Interface LSI (Q7) latches this data in sync with the STB signal.

The BUSY signal is switched ON as the data is processed. When processing is completed, the BUSY signal is switched OFF and an ACK signal is sent to the host to request more data. The BUSY signal is also switched ON when the printer is not able to receive data (buffer is full, printer is deselected or an error condition exists).

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Service Guide ML380

Chapter 2 Principles of Operation

2.1.05 Printhead Drive Circuit

This circuit is used to drive the 24 print wires. The signals HD1 through HD24 control the individual print wires. The HD ON signal (even/odd trigger) enables the drive circuit when printing is desired. The head drive duration is determined by an RC integrating circuit which modifies the HD ON pulsewidth. The pulsewidth of the HD ON signal varies with the number of pins being driven. The drive time increases as more pins are driven, and decreases as fewer pins are driven. The RC circuit compensates for the fluctuation of drive voltage (+35 vdc).

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Service Guide ML380

Chapter 2 Principles of Operation

2.1.06 Spacing Drive Circuit

The space motor is driven by a two-phase pulse motor. The phase signals (Phase 1, Phase 2, Phase 3 and Phase 4) and the basic pulse signals are output from the LSI (Q7). The pulse signals are modified by the drive voltage compensation circuit and sent back to the LSI (Q7).

The space overdrive signals (Phase 1DVOV, Phase 2 DVOV, Phase 3DVOV and Phase 4DVOV) switch Q16 and Q17 ON, setting up the proper phase relationship of analog space motor drive signals (SP Phase 1 through SP Phase 4). These signals are then sent to the space motor.

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Service Guide ML380

Chapter 2 Principles of Operation

2.1.07 Line Feed Circuit

The line feed motor shaft is held stationary by + 8 vdc (the holding current is approximately 30 ma) whenever in a stopped position.

During line feed operation, the line feed motor is driven in accordance with the LF OVD signal. The signals LFMO Phase 1 through LFMO Phase 4 establish the proper phase relationship for driving the motor.

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Oki ML380 SERVICE MANUAL

Specifications and Main Features

Frequently Asked Questions

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