OKI ML521 Bedienungsanleitung

Page: 1Service Guide ML520/521Chapter 0 About This Manual ML520 // ML521Dot Matrix PrintersAdobe Acrobat printable reference copy of the OKIDATA Servi

Page: 4Service Guide ML520/521Chapter 1 Product Specifications 1.2 PHYSICAL SPECIFICATIONS1.2.01 DimensionsNOTE:Dimensions INCLUDE the platen knob, ac

Page: 74Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.05 Pull-up Roller Assembly1. Perform this procedure: 3.2.01.2. Open the acc

Page: 75Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.06 Upper Cover, Access Cover, and Sheet Guide Assemblies1. Perform this pro

P/N 51009401 Guide: Sheet (Narrow) RSPL 520 B.2.02P/N 51009501 Guide: Sheet (Wide) RSPL 521 B.2.02P/N 53066902 Cover: Upper (Narrow) RSPL 520 B.2.02P/

Page: 76Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.07 Control Board (FJIM)1. Perform these procedures: 3.2.01, and 3.2.06 .2.

P/N 55072401 PCB: FJIM (w/o ROM) RSPL Both B.2.03P/N 55938301 IC: EEPROM BR93CC46A RSPL Both B.2.03Copyright 1997, Okidata, Division of OKI America, I

Page: 77Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.08 Power Supply Assembly1. Perform these procedures: 3.2.01 and 3.2.06 .2.

P/N 56412401 Transformer: 120 V ML520 RSPL 520 B.2.03P/N 56412402 Transformer: 120 V ML521 RSPL 521 B.2.03P/N 55073201 PCB: Filter 120 V RSPL Both B.2

Page: 78Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.09 Operator Panel PCB (LEOP)1. Perform these procedures: 3.2.01, 3.2.06 , a

Page: 79Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.10 PC Connector1. Perform these procedures: 3.2.01, 3.2.02 , and 3.2.04 .2.

P/N 56729601 Connector: PC HD40 RSPL Both B.2.07Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business P

Page: 5Service Guide ML520/521Chapter 1 Product Specifications 1.3 POWER REQUIREMENTS1.3.01 Input Power120 VAC: +5.5 / -15%230/240 VAC: +10 / -14%1.3.

Page: 80Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.11 Space Motor and Roller Guide Assemblies1. Perform these procedures: 3.2.

P/N 53343001 Holder: Connector (L) RSPL Both B.2.07P/N 53343101 Holder: Connector (R) RSPL Both B.2.07P/N 56510401 Motor: Space Assembly RSPL Both B.2

Page: 81Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.12 Carriage Cable1. Perform these procedures: 3.2.01, 3.2.06 , 3.2.07 , and

Page: 82Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.13 Space Rack1. Perform these procedures: 3.2.01, 3.2.02 , 3.2.04 , 3.2.10

P/N 50923501 Spring: Tension (Space Rack) RSPL Both B.2.04P/N 53563301 Rack: Space (Narrow) RSPL 520 B.2.04P/N 53563401 Rack: Space (Wide) RSPL 521 B.

Page: 83Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.14 Roller/Holder Backup Assembly1. Perform these procedures: 3.2.01, 3.2.02

Page: 84Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.15 Guide Rail and Adjust Cam1. Perform these procedures: 3.2.01, 3.2.02 , 3

P/N 51009801 Guide: Rail (Narrow) RSPL 520 B.2.04P/N 51009901 Guide: Rail (Wide) RSPL 521 B.2.04P/N 53067701 Cam: Adjust RSPL Both B.2.04Copyright 199

Page: 85Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.16 Left Ground Plate1. Perform these procedures: 3.2.01, 3.2.06 , and 3.2.0

Page: 86Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.17 Right Ground Plate1. Perform these procedures: 3.2.01, and 3.2.06 .2. Pu

Page: 6Service Guide ML520/521Chapter 1 Product Specifications 1.4 ENVIRONMENTAL CONDITIONS1.4.01 Acoustic RatingNear Letter Quality ModeMicroline 520

Page: 87Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.18 Rear and Cut Sheet Paper Feed Sensor Levers1. Perform these procedures:

Page: 88Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.19 Platen Assembly1. Perform these procedures: 3.2.01, and 3.2.06 .2. Move

P/N 50098301 Platen Assembly (Narrow) RSPL 520 B.2.05P/N 50098302 Platen Assembly (Wide) RSPL 521 B.2.05Copyright 1997, Okidata, Division of OKI Ameri

Page: 89Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.20 Paper Chute Assembly1. Perform these procedures: 3.2.01, 3.2.06 , and 3.

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Page: 90Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.21 Line Feed Motor Assembly1. Perform these procedures: 3.2.01, 3.2.06 , 3.

P/N 56627201 Cord: Connection Line Feed RSPL Both B.2.04Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Bu

Page: 91Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.22 Reset SpringCAUTION:Please read through this entire procedure before per

Page: 92Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.23 Idle Gear and Change Lever1. Perform these procedures: 3.2.01, 3.2.06 ,

P/N 50805101 Lever: Change RSPL Both B.2.05P/N 51228201 Gear: Idle RSPL Both B.2.05Copyright 1997, Okidata, Division of OKI America, Inc. All rights r

Page: 7Service Guide ML520/521Chapter 1 Product Specifications 1.5 AGENCY APPROVALS1.5.01 ListingsUL No: UL Standard No. 1950 D3CSA No: CSA Standard 2

Page: 93Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.24 Pressure Spring1. Perform these procedures: 3.2.01, 3.2.06 , 3.2.07 , 3.

P/N 50805201 Lever: Switch RSPL Both B.2.06P/N 50805301 Cam: Release RSPL Both B.2.05P/N 50923301 Spring: Pressure (Narrow) RSPL 520 B.2.06P/N 5092340

Page: 94Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.25 Carriage ShaftCAUTIONThe space motor assembly, etc. may be left in place

P/N 50098901 Carriage: Frame Set RSPL Both B.2.07P/N 50923601 Spring: Support Protect Reset RSPL Both B.2.04P/N 53067601 Protector: Support (Assembly)

Page: 95Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.26 Leaf Spring1. Perform these procedures: 3.2.01, 3.2.06 , 3.2.07 , 3.2.16

Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

Page: 96Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.27 Bottom Paper Sensor Levers1. Perform these procedures: 3.2.01, 3.2.06 ,

P/N 50804701 Lever: Bottom Sensor RSPL Both B.2.04P/N 51227801 Shaft: Front Release Gear RSPL 520 B.2.06 (Narrow)P/N 51227901 Shaft: Front Release Gea

Page: 97Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.28 Front Pressure Roller Assembly1. Perform these procedures: 3.2.01, 3.2.0

Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

Page: 8Service Guide ML520/521Chapter 1 Product Specifications 1.6 OPERATIONAL SPECIFICATIONS1.6.01 Character Matrix SizesTable of Print Speed and Cha

Page: 98Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.29 Tractor Assembly1. Perform these procedures: 3.2.01, 3.2.06 , 3.2.07 , 3

P/N 50097501 Tractor: Assembly (Narrow) RSPL 520 B.2.06P/N 50097502 Tractor: Assembly (Wide) RSPL 521 B.2.06P/N 51228001 Gear: Change RSPL Both B.2.05

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Page: 99Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.30 Main Frame1. All disassembly procedures must be carried out to reach the

Page: 100Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.3 PRINTER ADJUSTMENTS3.3.01 General InformationThis section contains the pro

Page: 101Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.3.02 Printhead Gap AdjustmentGeneral InformationBefore performing this adjus

1. Remove the upper cover and pull roller assembly.2. Move the change lever to the rear paper feed position.3. Rotate the platen.4. Set the gap change

Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this ma

Page: 102Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.3.03 Key CombinationsKey CombinationsDescriptionSEL + LF (Hold during Power-

Page: 103Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.3.04 Menu OperationGeneral InformationThe menu is used to customize the prin

Characters Per Line Characters Per Inch80 1096 12120 15137 17.1160 20Microline 521Characters Per Line Characters Per Inch136 10163 12204 15233 17.1272

could damage / destroy the printhead, platen, and ribbon.4. Press and hold the SHIFT switch while pressing the SEL switch.5. The MENU lamp will light.

To access the menu when the printer is set to Limited Operation, follow this procedure.1. Verify that continuous feed paper is installed.2. Verify tha

Page: 104Service Guide ML520/521Chapter 3 Maintenance & Disassembly Menu SettingsFactory default settings are printed in Bold Italic.The tables sh

Page Width *13.6" 8"Page Length11 11 2/3 12 14 17 3 3.5 4 5.5 6 7 8 8.5 "Gap ControlAuto Gap Semi Auto Gap 1 2 3 4 5

Paper Out OverrideNo YesPrint RegistrationO 0.05 mm Left 0.10 mm Left 0.15 mm Left 0.20 mm Left 0.25 mm Left 0.25 mm Right 0.20 mm Right 0.15 mm Rig

The tables show all possible menu settings available with the Microline 520/521.What you will actually see depends on the active emulation and the opt

Page: 105Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.3.05 Top of FormGeneral InformationTop of Form is the distance from the top

Page: 106Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.3.06 Paper ParkGeneral InformationPaper Park allows the user to print using

Page: 107Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.3.07 Tear FeatureNOTE:Tear is activated by pressing TEAR. It is a manual pro

Page: 108Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.3.08 Forms Tear OffNOTE:Tear is activated by pressing TEAR. It is a manual p

1.6.05 EmulationsNOTE: The emulations are co-residentEpson FXIBM ProprinterMicroline Standard1.6.06 FontsNear Letter QualityCourierUtilityGothicHigh S

Press Micro Feed Up to advance the paper.Press Micro Feed Down to retract the paper.6. Enter Menu Mode.7. Enable Form Tear Off.8. Exit Menu Mode.Setti

Page: 109Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.3.09 ResetsReset Menu to Factory DefaultsCAUTION:Once the menu has been rese

Page: 110Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.4 CLEANING3.4.01 General InformationAn accumulation of paper dust is the mos

Page: 111Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.5 LUBRICATION3.5.01 General InformationIf the lubrication procedures are not

3.5.06 Areas Not LubricatedLubricant should never contact the parts listed below.1. Ribbon2. Platen Assembly (Rubber Face)3. Pressure Roller (Rubber F

Page: 112Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.6 SHIPPING INSTRUCTIONS3.6.01 Return for ServiceCAUTION:When shipping the pr

Page: 113Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.1.01 IntroductionThis section is used to isolate problems to the assembly le

Page: 114Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.1.02 Printer Serial Number IdentificationTo identify the revision level of a

Page: 115Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.1.03 Firmware Revision IdentificationTo identify the revision level and part

Page: 116Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.2 REPORTING PROBLEMS - General Information4.2.01 General InformationOkidata

RS232C Serial1.6.10 Line Feed IncrementsFixed6 lines per inch (lpi) [0.167 inch (4.23 millimeters)]8 lines per inch (lpi) [0.125 inch (3.175 millimete

Page: 117Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.2.02 Problem ListsTechnicians frequently request a list of common problems s

Page: 118Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.2.03 Reporting MethodsOkilink IIYou may use Okilink II to report your findin

Page: 119Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.3 TROUBLESHOOTING UPDATES4.3.01 General InformationOkidata distributes updat

Page: 120Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.4 TROUBLESHOOTING TIPS4.4.01 Preliminary Checks1. Is the product being opera

Page: 121Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.4.02 Problem CategoriesThere are three categories of problems that you might

Page: 122Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.4.03 START HERE FlowchartSTARTPower ON the unit.Does the printer initialize?

Page: 123Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.4.04 Tips for Preventing Image Problems1. Make sure that the ribbon is not &

Page: 124Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.4.05 Common Problems1. Nothing happens when the unit is powered on.The unit

Handbook, the more compatible it will be with your printer. If your software does not have any of the indicated drivers available, check with the soft

the initialization string may still override the printer MENU and / or front panel settings.The I-Prime signal is sent over the parallel interface (pi

Paper ParkAutomatic Paper LoadingForms Tear Off1.6.15 Paper LoadingAuto Loading (Top Feed)Press FORM FEED / Load switch to feed paper to default posit

Page: 125Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.5 ABNORMAL OUTPUT - Output Samples4.5.01 Output SamplesLight Print on the En

2. Defective platen. Replace the platen.Smeared PrintPossible Causes:1. Ribbon protector is missing or broken. Replace the ribbon protector.2. Verify

Drifting MarginPossible Causes:1. Power OFF the printer. Move the carriage assembly. The carriage should move smoothly. If it does not, remove the cau

Page: 126Service Guide ML520/521Chapter 4 Failure & Repair Analysis Left Margin Drifting ProblemNOTE:This information is also provided in Technica

Page: 127Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.6 FAULT ALARMS4.6.01 General InformationFollow these guidelines when using t

Page: 128Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.6.02 ALARM/LED Display Troubleshooting Table IndexCAUTION:Always check that

Blinking On 12 Blinking On On 13 Blinking On On 14 Blinking On 15 Bl

Page: 129Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.6.03 ALARM/LED Display Troubleshooting TablesCAUTION:Always check that all c

8 Printhead Connection Alarm (2)Self adjust was not successful. Head gap is too small or too narrow.Check the printhead connection. Then replace t

Page: 130Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.7 REPAIR ANALYSIS PROCEDURES (RAPs)4.7.01 Using the RAPsWhen using the Repai

1. Printhead Gap AdjustmentThis is a SERVICE ADJUSTMENT made by a technician.It is covered in Section 3.3 of this Service Handbook.The Adjustment meas

Page: 131Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.7.02 RAP IndexRAP Number Description 1 No Power Supplied to Printer 2 No S

Page: 132Service Guide ML520/521Chapter 4 Failure & Repair Analysis RAP 01 No Power Supplied to PrinterSTARTThe printer does not power On when the

1. Ribbon Feed Mechanism.2. Carriage Cable.3. Main Control Board4. PROM 05CAHas the problem been resolved?Yes End of procedure.No Contact Technical Su

Page: 133Service Guide ML520/521Chapter 4 Failure & Repair Analysis RAP 02 No Spacing OperationSTARTThe alarm LED blinks.Is the carriage assembly

Has the problem been resolved?Yes End of procedure.No Contact Technical Support.Copyright 1997, Okidata, Division of OKI America, Inc. All rights rese

Page: 134Service Guide ML520/521Chapter 4 Failure & Repair Analysis RAP 03 Printhead Homing ErrorSTARTPrinthead does not return to the home positi

Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this ma

Page: 135Service Guide ML520/521Chapter 4 Failure & Repair Analysis RAP 04 Paper Jam During Paper LoadingSTARTCheck paper path release lever for p

Page: 136Service Guide ML520/521Chapter 4 Failure & Repair Analysis RAP 05 Printhead Pins Not FiringSTARTMissing dots on output.Verify that the pr

Page: 137Service Guide ML520/521Chapter 4 Failure & Repair Analysis RAP 06 Poor Print QualitySTARTIs the print head gap properly set?Yes Go to ANo

Table of Contents PageService Guide ML520/5210 About This ManualFront Cover 1Copyright Information 21 Product Specifications1.1.01 General Information

Used when the same paper is used ALL of the time.Bypasses the automatic head gap adjustment.1 is the narrowest head setting.9 is the widest head setti

Page: 138Service Guide ML520/521Chapter 4 Failure & Repair Analysis RAP 07 Ribbon Feed ProblemSTARTThe ribbon feed does not function properly.Veri

Page: 139Service Guide ML520/521Chapter 4 Failure & Repair Analysis RAP 08 Line Feed ProblemSTARTNo line feed operation.Make sure that the line fe

Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this ma

Page: 140Service Guide ML520/521Chapter 4 Failure & Repair Analysis RAP 09 Operation Panel MalfunctionSTARTThe operation panel does not function p

Page: 141Service Guide ML520/521Chapter 4 Failure & Repair Analysis RAP 10 Parallel Interface ProblemSTARTNo parallel port communication.Is the SE

Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this ma

Page: 142Service Guide ML520/521Chapter 4 Failure & Repair Analysis RAP 11 Serial Interface ProblemSTART.Are you using a cable with the proper num

No Replace the RS232C board.Are + 8 vdc / - 8 vdc present on the main control board? (Refer to Appendix A of this Service Handbook).Yes Replace the RS

Page: 143Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.8 PRINTER TESTS4.8.01 General InformationThis section covers the tests liste

Page: 144Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.8.02 Rolling ASCII TestGeneral InformationThe rolling ASCII test is a contin

Page: 9Service Guide ML520/521Chapter 1 Product Specifications 1.7 PAPER SPECIFICATIONSCAUTION:Use Bottom Feed and/or optional Pull Tractor for card s

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Page: 145Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.8.03 Font TestGeneral InformationThe font test is a one page sample printout

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Page: 146Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.8.04 Serial Interface Loopback TestNOTE:In order to run this test, the seria

Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this ma

Page: 147Service Guide ML520/521Chapter 4 Failure & Repair Analysis Serial Cable InformationThe information in this section will help you make a s

Page: 148Service Guide ML520/521Chapter 4 Failure & Repair Analysis Serial Interface Signal RequirementsCopyright 1997, Okidata, Division of OKI A

Page: 149Service Guide ML520/521Chapter 4 Failure & Repair Analysis Commonly Used Serial Cable ConfigurationsIBM 25-Pin Cable ConfigurationCompute

Page: 150Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.8.05 Hexadecimal Dump ModeGeneral InformationThe hexadecimal dump mode allow

Page: 151Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.9 RESISTANCE CHECKS4.9.01 General DescriptionThe charts on the following pag

Width: 7.2 to 14.3 inches (18.3 to 36.3 centimeters)Width: Microline 520 7.2 to 8.5 inches (18.2 to 21.5 centimeters)Microline 521 7.2 to 14.3 inches

Page: 152Service Guide ML520/521Chapter 4 Failure & Repair Analysis Layout DiagramCopyright 1997, Okidata, Division of OKI America, Inc. All right

Page: 153Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.9.02 PrintheadInterconnect Diagram: Control Board to PrintheadNOTE:The print

Page: 154Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.9.03 Line Feed Motor ResistanceThe resistance of each coil should be approxi

Page: 155Service Guide ML520/521Chapter 4 Failure & Repair Analysis 4.9.04 Space Motor ResistanceThe resistance of each coil should be approximate

Page: 156Service Guide ML520/521Chapter A Reference Charts A.1 OVERVIEW - A.1.01 General InformationThis section describes the characteristics of the

Page: 157Service Guide ML520/521Chapter A Reference Charts A.2 INDEX TO CHARTSDescription Board Designation Section Main Controller Board FJIM A.2.01

Page: 158Service Guide ML520/521Chapter A Reference Charts Board LayoutCopyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See

Page: 159Service Guide ML520/521Chapter A Reference Charts A.2.01 Main Controller Board (FJIM)FunctionThe main controller board contains a microproces

Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this ma

Page: 160Service Guide ML520/521Chapter A Reference Charts A.2.02 Operator Panel Board (LEOP)FunctionThe operator panel control LSI send commands to t

NOTE:Roller marks may mar the transparency under high temperature / high humidity conditions.Weight: 12 to 24 lbs. (45 to 90 g/m 2 )Width: Microline 5

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Page: 161Service Guide ML520/521Chapter A Reference Charts A.2.03 Power Supply AssemblyFunctionThe power supply board is comprised of a noise filter b

Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this ma

Page: 162Service Guide ML520/521Chapter A Reference Charts A.2.04 Space Motor BoardFunctionThe space motor board contains an encoder disk and photosen

Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this ma

Page: 163Service Guide ML520/521Chapter A Reference Charts A.2.05 RS232-C Serial Interface Board - Option (LXHI)FunctionThis board provides you serial

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Page: 164Service Guide ML520/521Chapter B Illustrated Parts Listing B.1 OVERVIEW - B.1.01 General InformationThis appendix will assist you in identify

Page: 165Service Guide ML520/521Chapter B Illustrated Parts Listing FormatThe format for this appendix is a series of tables with diagrams. The tables

Page: 166Service Guide ML520/521Chapter B Illustrated Parts Listing Current Part NumbersOkidata has made every effort to include current part numbers

NOTE:The recommended weight is specific to paper type.Minimum: 9 lb. (35 g/m 2 )Maximum: 120 lb. (90 g/m 2 )1.7.06 WidthNOTE:The recommended width is

Page: 167Service Guide ML520/521Chapter B Illustrated Parts Listing B.1.02 Definition of TermsAssembliesAssemblies are parts grouped under a single de

information updates.Okidata distributes the TSBs through Okilink II. The TSBs are issued monthly.520This part is specific to the Microline 520 printer

Page: 168Service Guide ML520/521Chapter B Illustrated Parts Listing B.1.03 Parts Ordering InformationService Center Reference GuideWhen a technician h

Page: 169Service Guide ML520/521Chapter B Illustrated Parts Listing B.2 CHARTSBelow is an index to the illustrated parts breakdown charts.Section Desc

Page: 170Service Guide ML520/521Chapter B Illustrated Parts Listing OverviewCopyright 1997, Okidata, Division of OKI America, Inc. All rights reserved

Page: 171Service Guide ML520/521Chapter B Illustrated Parts Listing B.2.01 PrinterPart numbers are subject to change. Refer to Okilink II for current

Page: 172Service Guide ML520/521Chapter B Illustrated Parts Listing B.2.02 Upper Cover AssemblyItem Okidata P/N Oki-J P/NDescription Comments Refer to

3 53067201 2PA4094-7382G1Cover: Access (Wide)RSPL 5213.2.06Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA

Page: 173Service Guide ML520/521Chapter B Illustrated Parts Listing B.2.03 Printer General AssemblyItem Okidata P/N Oki-J P/NDescription Comments Refe

5 55937502 4YA4042-1516G2PCB: LEOP (Operator. Panel)RSPL Both3.2.096 53562703 3PP4025-3670G3Panel: Operator RSPL Both3.2.097 56412401 4YB4049-7030P1Tr

Page: 10Service Guide ML520/521Chapter 1 Product Specifications 1.8 MEMORY SPECIFICATIONS1.8.01 EEPROM1 Kbit serial EEPROM (used to store Menu data)1.

Page: 174Service Guide ML520/521Chapter B Illustrated Parts Listing B.2.04 Printer UnitItem Okidata P/N Oki-J P/NDescription Comments Refer to B.1.02D

6 56627201 3PB4025-3356P1Cord: Connection Line FeedRSPL Both 3.2.217 56510302 3PB4025-3357P2Motor: Line Feed Assembly RSPL Both 3.2.218 51228601 3PB4

Page: 175Service Guide ML520/521Chapter B Illustrated Parts Listing B.2.05 Printer UnitItem Okidata P/N Oki-J P/NDescription Comments Refer to B.1.02D

5 51228201 4PP4025-3353P1Gear: Idle RSPL Both3.2.236 50805101 2PP4025-3354P1Lever: Change RSPL Both3.2.237 50923201 3PP4025-3355P1Spring: Reset RSPL B

Page: 176Service Guide ML520/521Chapter B Illustrated Parts Listing B.2.06 Printer UnitItem Okidata P/N Oki-J P/NDescription Comments Refer to B.1.02D

4 53341101 4PP4025-3317P1Holder: Front RollerRSPL Both3.2.285 53341202 4PP4025-3327G1Roller: Front PressureRSPL Both3.2.286 51227801 3PP4025-3318P1Sha

Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this ma

Page: 177Service Guide ML520/521Chapter B Illustrated Parts Listing B.2.07 Carriage AssemblyItem Okidata P/N Oki-J P/NDescription Comments Refer to B.

4 56729601 224A1285P0400Connector: PC HD40RSPL Both3.2.105 53343001 4PP4025-3433P1Holder: Connector (L)RSPL Both3.2.116 53343101 4PP4025-3434P1Holder

Page: 178Service Guide ML520/521Chapter B Illustrated Parts Listing B.2.08 OptionsItem Okidata P/N Oki-J P/NDescription Comments Refer to B.1.02Disass

Page: 11Service Guide ML520/521Chapter 1 Product Specifications 1.9 CONSUMABLES1.9.01 RibbonCAUTION:Using a non-Okidata ribbon may damage the printhea

3 70023101 N/A Kit: Push Tractor (Bottom) WideOption 521 N/A4 70023301 N/A Kit: Roll Paper StandOption 520 N/A5 70000803 N/A Kit: Parallel Interfac

Page: 179Service Guide ML520/521Chapter B Illustrated Parts Listing B.2.09 Option PartsItemOkidata P/N Oki-J P/NDescription Comments Refer to B.1.02Di

8 53067501 1PP4053-2575P1Cover: Side (Right) Cut-Sheet FeederOption RSPL Both N/A9 53480901 1PP4043-1891P4Supporter: Front Sheet (W) Cut-Sheet Feede

Page: 180Service Guide ML520/521Chapter B Illustrated Parts Listing B.2.10 Consumables52107001 N/A Ribbon: Black Consumable Both 3.2.02Copyright 1997,

Page: 181Service Guide ML520/521Chapter B Illustrated Parts Listing B.2.11 Packing MaterialsItemOkidata P/N Oki-J P/NDescription Comments Refer to B.1

Page: 182Service Guide ML520/521Chapter B Illustrated Parts Listing B.2.12 DocumentationItemOkidata P/N Oki-J P/NDescription Comments Refer to B.1.02D

8 B 59256802 N/A Handbook: Printer Document Part of 2 BN/A9 59258401 N/A Manual: Maintenance Document Both N/A10 59261000 N/A Manual: TroubleshootingD

Page: 183Service Guide ML520/521Chapter B Illustrated Parts Listing B.2.13 Service Training Kit Revision ListP/N 58229401 Microline 520/521 Service T

16 A 52063202 N/A Label: Service Videotape CaseDocument N/A17 A 52063203 N/A Label: Service Videotape FrontDocument N/A18 A 52063204 N/A Label: Se

Item Okidata P/N Oki-J P/NDescription Comments Refer to B.1.02Disassembly Procedure1 C 58229403 N/A Kit: ML520/521 Service TrainingDocument Both N/A2

Page: 12Service Guide ML520/521Chapter 1 Product Specifications 1.10 OPTIONS - Cut Sheet Feeders1.10.01 Cut Sheet FeedersSingle BinThe CSF-5000 is a n

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Page: 13Service Guide ML520/521Chapter 1 Product Specifications 1.10.02 Pull Tractor KitNOTE:The Pull Tractor Kit (P/N 70023001) is a narrow feeder fo

Table of Contents Page...Head Drive Time 39...Print Speed 40...%Head Overheat Alarm Processing 41...2.1.08 Power Supply Circuit 422.2

Page: 14Service Guide ML520/521Chapter 1 Product Specifications 1.10.04 Bottom Push Tractor KitNOTE:The Bottom Push Tractor Kit (P/N 70022901) is a na

Page: 15Service Guide ML520/521Chapter 1 Product Specifications 1.10.05 Serial InterfaceSuper-Speed 19.2K RS-232CReady/Busy/X-On/X-Off ProtocolsCan be

Page: 16Service Guide ML520/521Chapter 1 Product Specifications 1.10.06 Roll Paper StandAdapts printer for use with roll-type paper (Model 520 only)In

Page: 17Service Guide ML520/521Chapter 1 Product Specifications 1.10.08 OKISmart Typer UtilityObtained via BRC (Business Reply Card) packaged with pri

Page: 18Service Guide ML520/521Chapter 1 Product Specifications 1.11 RELIABILITY1.11.01 Mean Time Before Failure (MTBF)Approximately 6,000 hours: 25%

Page: 19Service Guide ML520/521Chapter 2 Principles of Operation 2.1 ELECTRICAL OPERATIONThe printer is comprised of the electrical components listed

Page: 20Service Guide ML520/521Chapter 2 Principles of Operation 2.1.01 Main Control BoardThe main control board is made up of the microprocessor, per

Page: 21Service Guide ML520/521Chapter 2 Principles of Operation Block DiagramCopyright 1997, Okidata, Division of OKI America, Inc. All rights reserv

Page: 22Service Guide ML520/521Chapter 2 Principles of Operation Program ROMLocation 05CA: 27C1024This 64k x 16 bit (1Mbit) EPROM contains the control

Page: 23Service Guide ML520/521Chapter 2 Principles of Operation RAMLocation 05CB: 511664ZThe RAM is CMOS dynamic RAM with 65,536 words x 16-bit confi

Table of Contents Page...3.2.11 Space Motor and Roller Guide Assemblies 80...3.2.12 Carriage Cable 81...3.2.13 Space Rack 82...3.2.14 Roller/Holde

Page: 24Service Guide ML520/521Chapter 2 Principles of Operation LSILocation 04B: MSM79VO35Detects the output of the two-phase sensor on the DC space

Page: 25Service Guide ML520/521Chapter 2 Principles of Operation Electrically Erasable Programmable Read Only Memory (EEPROM)(Location 03C: 93CS46)The

Page: 26Service Guide ML520/521Chapter 2 Principles of Operation 2.1.02 InitializationThis printer is initialized when the printer is powered on or wh

Page: 27Service Guide ML520/521Chapter 2 Principles of Operation 2.1.03 Parallel Interface ControlThe parallel data input from the host to the interfa

Page: 28Service Guide ML520/521Chapter 2 Principles of Operation 2.1.04 Print ControlThe print data is transmitted as serial data from the LSI to the

Page: 29Service Guide ML520/521Chapter 2 Principles of Operation LSI/Printhead InterfaceThe connection between the LSI and the printhead is made with

Page: 30Service Guide ML520/521Chapter 2 Principles of Operation Gap Adjust ControlThe Gap Adjust LSI receives stroke length information for all of th

Page: 31Service Guide ML520/521Chapter 2 Principles of Operation Print Compensation ControlThe printhead compensates for the shape of the platen as sh

Page: 32Service Guide ML520/521Chapter 2 Principles of Operation 2.1.05 Space and Line Feed (SP/LF) Motor ControlThe LSI (Location 04B: MSM79V035) gen

Page: 33Service Guide ML520/521Chapter 2 Principles of Operation Line Feed Motor ControlThe SP/LF motor driver (Location 5A: MHM2025) drives the line

Table of Contents Page...4.4.04 Tips for Preventing Image Problems 123...4.4.05 Common Problems 1244.5 Abnormal Output - Output Samples 125...Left

Page: 34Service Guide ML520/521Chapter 2 Principles of Operation Space Motor ControlThe SP/LF motor driver (Location 5A: MHM2025) drives the three-pha

Page: 35Service Guide ML520/521Chapter 2 Principles of Operation Encoder DiskAs the space motor operates, the encoder disk spins. When the encoder dis

Page: 36Service Guide ML520/521Chapter 2 Principles of Operation 2.1.06 Operation PanelThe Serial I/O Port (Ports 20 - 23) of the MPU reads the operat

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Page: 37Service Guide ML520/521Chapter 2 Principles of Operation 2.1.07 Alarm CircuitDriver Circuit Alarm ProcessingThe printhead driver output and th

Page: 38Service Guide ML520/521Chapter 2 Principles of Operation Low Motor Drive Voltage Alarm+40V is converted into the POWLEV signal (0 vdc to +5 vd

Page: 39Service Guide ML520/521Chapter 2 Principles of Operation Head Drive TimeThe head drive time is modified to compensate for the amount of the vo

Page: 40Service Guide ML520/521Chapter 2 Principles of Operation Print SpeedActual Voltage (+40 vdc)Passes Required Relative Print Speed+34 vdc or gre

Page: 41Service Guide ML520/521Chapter 2 Principles of Operation Head Overheat Alarm ProcessingIf the printhead temperature exceeds 110 degrees Celsiu

Page: 42Service Guide ML520/521Chapter 2 Principles of Operation 2.1.08 Power Supply CircuitThe switching type power supply circuit supplies the +5 vd

Table of Contents Page...Format 165...Current Part Numbers 166...B.1.02 Definition of Terms 167...B.1.03 Parts Ordering Information 168B.2

Page: 43Service Guide ML520/521Chapter 2 Principles of Operation 2.2 MECHANICAL OPERATION2.2.01 Printhead MechanismThe printhead is a spring-charged,

Page: 44Service Guide ML520/521Chapter 2 Principles of Operation Printhead Gap InformationThree items factor into printhead gap information.1. Printhe

Semi Auto GapSimilar to Auto Gap.Automatically determines paper thickness of the first page.During single-sheet feed, each pages thickness IS NOT chec

Page: 45Service Guide ML520/521Chapter 2 Principles of Operation Interconnect Diagram: Control Board to PrintheadNOTE:The printhead coil resistance va

Page: 46Service Guide ML520/521Chapter 2 Principles of Operation Line Feed Motor ResistanceThe resistance of each coil should be approximately 13 ohms

Page: 47Service Guide ML520/521Chapter 2 Principles of Operation Space Motor ResistanceThe resistance of each coil should be approximately 5 ohms.Copy

Page: 48Service Guide ML520/521Chapter 2 Principles of Operation Printhead OperationWhen the printhead is idle, the armature is attracted to the perma

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Page: 49Service Guide ML520/521Chapter 2 Principles of Operation Printhead TemperatureIf the printhead temperature exceeds 110 degrees Celsius, the pr

Page: 50Service Guide ML520/521Chapter 2 Principles of Operation 2.2.02 Spacing MechanismThe spacing mechanism consists of a carriage shaft (mounted p

Page: 2Service Guide ML520/521Chapter 0 About This Manual This document may not be reproduced without the written permission of the Okidata Technical

Page: 51Service Guide ML520/521Chapter 2 Principles of Operation Spacing OperationThe carriage frame, which contains the printhead and space motor, mo

Page: 52Service Guide ML520/521Chapter 2 Principles of Operation 2.2.03 Head Gap MechanismThe head gap is automatically set for the thickness of the m

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Page: 53Service Guide ML520/521Chapter 2 Principles of Operation Ribbon Drive OperationThe ribbon drive mechanism feeds the ribbon in synchronization

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Page: 54Service Guide ML520/521Chapter 2 Principles of Operation 2.2.05 Line Feed MechanismThe line feed operation is accomplished by activating the l

Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this ma

Page: 55Service Guide ML520/521Chapter 2 Principles of Operation Cut Sheet/Continuous Sheet Switching MechanismTop Feed (for cut sheet paper)When cut

Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this ma

Page: 56Service Guide ML520/521Chapter 2 Principles of Operation Cut Sheet Paper Feed OperationAs the line feed motor rotates, power is transferred th

Proprinter is a registered trademark of International Business Machine Corporation.Windows is a trademark of Microsoft CorporationCopyright 1997, Okid

Page: 57Service Guide ML520/521Chapter 2 Principles of Operation Continuous Paper Feed (Rear Tractor Mechanism)As the platen rotates, power is transfe

Page: 58Service Guide ML520/521Chapter 2 Principles of Operation Continuous Paper Feed (Pull Tractor Mechanism)Bottom feed of continuous sheets is pos

Page: 59Service Guide ML520/521Chapter 2 Principles of Operation Continuous Paper Feed (Bottom Tractor Feed Mechanism)As the platen rotates, power is

Page: 60Service Guide ML520/521Chapter 2 Principles of Operation Continuous Paper Feed (Push/Pull Tractor Mechanism)This mechanism consists of an opti

Page: 61Service Guide ML520/521Chapter 2 Principles of Operation 2.2.06 Paper Detection MechanismTop Feed Paper DetectionWhen cut sheet paper is inser

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Page: 62Service Guide ML520/521Chapter 2 Principles of Operation 2.2.07 Support Protector MechanismDuring printer initialization, the support protecto

Page: 63Service Guide ML520/521Chapter 2 Principles of Operation 2.2.08 Automatic Paper LoadThe Microline 520/521 printers will automatically detect c

Page: 64Service Guide ML520/521Chapter 2 Principles of Operation Continuous Feed PaperSet the change lever to either the REAR FEED or BOTTOM FEED posi

Page: 65Service Guide ML520/521Chapter 2 Principles of Operation 2.2.09 Paper ParkIf continuous feed paper is installed and printing on cut sheet pape

Page: 3Service Guide ML520/521Chapter 1 Product Specifications 1.1.01 General InformationThe Microline 520 and Microline 521 are letter quality, nine-

Page: 66Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.1.01 General InformationThis section lists the parts replacement, adjustment,

Page: 67Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.1.02 Maintenance ToolsThe following tools are required to service the printer

Page: 68Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.1.03 Maintenance Precautions1. Do not disassemble the unit if it is operating

Page: 69Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2 DISASSEMBLY/ASSEMBLY PROCEDURESGeneral InformationThis section contains the

Page: 70Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.01 Preliminary Items1. Press the AC switch (1) and power off the printer.2.

Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)

Page: 71Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.02 Printhead Assembly1. Perform this procedure: 3.2.01.2. Open the access c

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Page: 72Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.03 Ribbon ProtectorCAUTIONYou MUST use a straight slot screwdriver to relea

Page: 73Service Guide ML520/521Chapter 3 Maintenance & Disassembly 3.2.04 Gear Case Assembly1. Perform these procedures: 3.2.01, and 3.2.02 .2. Us