Page 2 - Front Cover; Product Specifications; Electrical Operation
Table of Contents Page Service Guide ML520/521 0 About This Manual Front Cover 1 Copyright Information 2 1 Product Specifications 1.1.01 General Information 3 ....1.2 Physical Specifications 4 ....1.3 Power Requirements 5 ....1.4 Environmental Conditions 6 ....1.5 Agency Approvals 7 ....1.6 Operatio...
Page 3 - Mechanical Operation - Printhead Mechanism; Maintenance & Disassembly
Table of Contents Page ........Head Drive Time 39 ........Print Speed 40 ........%Head Overheat Alarm Processing 41 ....2.1.08 Power Supply Circuit 42 2.2 Mechanical Operation - Printhead Mechanism 43 ........Printhead Gap Information 44 ........Interconnect Diagram: Control Board to Printhead 45 .....
Page 4 - Printer Adjustments; Failure & Repair Analysis; Reporting Problems - General Information
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/Holder Backup Assembly 83 ....3.2.15 Guide Rail and Adjust Cam 84 ....3.2.16 Left Ground Plate 85 ....3.2.17 Right Ground Plate 86 ....3.2.18 Rear and ...
Page 5 - Resistance Checks; A Reference Charts
Table of Contents Page ....4.4.04 Tips for Preventing Image Problems 123 ....4.4.05 Common Problems 124 4.5 Abnormal Output - Output Samples 125 ....Left Margin Drifting Problem 126 4.6 Fault Alarms 127 ....4.6.02 ALARM/LED Display Troubleshooting Table Index 128 ....4.6.03 ALARM/LED Display Trouble...
Page 7 - Chapter 0 About This Manual
Page: 2 Service Guide ML520/521 Chapter 0 About This Manual 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 f...
Page 8 - Windows is a trademark of Microsoft Corporation
Proprinter is a registered trademark of International Business Machine Corporation. Windows is a trademark of Microsoft Corporation 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://bp...
Page 9 - Chapter 1 Product Specifications; typewriter on checks, labels and envelopes.
Page: 3 Service Guide ML520/521 Chapter 1 Product Specifications 1.1.01 General Information The Microline 520 and Microline 521 are letter quality, nine-pin, dot-matrix printers which utilize OKISMART paper handling. Patented Okidata technology does away with the manual head gap adjustment. The prin...
Page 12 - Near Letter Quality Mode
Page: 6 Service Guide ML520/521 Chapter 1 Product Specifications 1.4 ENVIRONMENTAL CONDITIONS 1.4.01 Acoustic Rating Near Letter Quality Mode Microline 520 54.9 dBA Microline 521 54.4 dBA Utility Mode Microline 520 57.2 dBA Microline 521 56.9 dBA Quiet Mode Microline 520 52.5 dBA Microline 521 52.3 ...
Page 16 - Optional
1.6.05 Emulations NOTE: The emulations are co-resident Epson FX IBM Proprinter Microline Standard 1.6.06 Fonts Near Letter QualityCourier UtilityGothic High Speed DraftGothic Bar CodeCode 39UPC AUPC EEAN 8EAN 13Interleaved 2 of 5Code 128 (A, B, C)Postnet 1.6.07 Front Panel Switches SELECT / Menu Mic...
Page 21 - Paper Feed Path: Bottom; Paper Feed Path: Rear or Bottom; Refer to the Printhead Gap Information, Section 1.6
Page: 9 Service Guide ML520/521 Chapter 1 Product Specifications 1.7 PAPER SPECIFICATIONS CAUTION: Use Bottom Feed and/or optional Pull Tractor for card stock and labels. 1.7.01 Types Card Stock Weight: 120 lbs. (450 g/m 2 ) Maximum Width: Microline 520 5 to 8 inches (12.7 to 20.3 centimeters) Micro...
Page 24 - Microline 520 8 inches Maximum
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 Width NOTE:The recommended width is specific to paper type. Paper Microline 520 Minimum: 3.5 inches ( 8.8 centimeters) Maximum: 10.5 inches (26.6 centimeters) Microline 521 Minimum: ...
Page 26 - Material
Page: 11 Service Guide ML520/521 Chapter 1 Product Specifications 1.9 CONSUMABLES 1.9.01 Ribbon CAUTION: Using a non-Okidata ribbon may damage the printhead and void any warranties. Material Nylon fabric, cartridge type, re-inking Type Black Ribbon Life (On average, at 10 characters per inch, Utilit...
Page 29 - Bottom Feed
Page: 13 Service Guide ML520/521 Chapter 1 Product Specifications 1.10.02 Pull Tractor Kit NOTE: The Pull Tractor Kit (P/N 70023001) is a narrow feeder for the Microline 520. The Pull Tractor Kit (P/N 70023201) is a wide feeder for the Microline 521. Bottom Feed Rear Feed (For Push/Pull Operation) P...
Page 31 - Can be configured through the Menu or OKISmart Utility Program
Page: 15 Service Guide ML520/521 Chapter 1 Product Specifications 1.10.05 Serial Interface Super-Speed 19.2K RS-232C Ready/Busy/X-On/X-Off Protocols Can be configured through the Menu or OKISmart Utility Program Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKID...
Page 33 - Obtained via BRC (Business Reply Card) packaged with printer; OKISmart Panel Emulator
Page: 17 Service Guide ML520/521 Chapter 1 Product Specifications 1.10.08 OKISmart Typer Utility Obtained via BRC (Business Reply Card) packaged with printer Includes: Typewriter Mode, Form Creation Utility and Barcode Utility 1.10.09 OKISmart Panel Utility Obtained via BRC (Business Reply Card) pac...
Page 34 - Approximately 15 minutes to major sub-assembly level
Page: 18 Service Guide ML520/521 Chapter 1 Product Specifications 1.11 RELIABILITY 1.11.01 Mean Time Before Failure (MTBF) Approximately 6,000 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 Approxi...
Page 35 - Chapter 2 Principles of Operation
Page: 19 Service Guide ML520/521 Chapter 2 Principles of Operation 2.1 ELECTRICAL OPERATION The printer is comprised of the electrical components listed below. Main Control Board Power Supply Assembly Transformer Filter Board Operator Panel Space Motor / Line Feed Motor Printhead Copyright 1997, Oki...
Page 36 - The MPU contains a 20 bit address bus, a 16 bit data bus.
Page: 20 Service Guide ML520/521 Chapter 2 Principles of Operation 2.1.01 Main Control Board The main control board is made up of the microprocessor, peripheral circuits, drive circuits, sensors and interface connectors. The power to the main control board is supplied by the transformer assembly thr...
Page 40 - Controls the external interface. The LSI is connected to the MPU.
Page: 24 Service Guide ML520/521 Chapter 2 Principles of Operation LSI Location 04B: MSM79VO35 Detects the output of the two-phase sensor on the DC space motor to control the motor drive phase. Transmits and receives serial data to and from the printhead based on the dot timing (which is derived fro...
Page 42 - The steps in Printer Initialization are listed below.; A reset operation initiated by I-PRIME does not reset the MPU.
Page: 26 Service Guide ML520/521 Chapter 2 Principles of Operation 2.1.02 Initialization This printer is initialized when the printer is powered on or when the I-PRIME-N signal is input from the host via the parallel interface. The steps in Printer Initialization are listed below. The RST-N signal i...
Page 57 - Print Speed
Page: 40 Service Guide ML520/521 Chapter 2 Principles of Operation Print Speed Actual Voltage (+40 vdc) Passes Required Relative Print Speed +34 vdc or greater 1 100% +32 vdc to +34 vdc 1 Approximately 85% +30 vdc to +32 vdc 1 Approximately 50% +30 vdc or less 2 Less than 50% Copyright 1997, Okidata...
Page 59 - IC logic levels, LED drive voltages
Page: 42 Service Guide ML520/521 Chapter 2 Principles of Operation 2.1.08 Power Supply Circuit The switching type power supply circuit supplies the +5 vdc, +/-8 vdc, 10 VAC and +40 vdc. Voltage/Signal Purpose +5 vdc IC logic levels, LED drive voltages +8 vdc Serial interface line voltage, comparator...
Page 64 - The resistance of each coil should be approximately 13 ohms.
Page: 46 Service Guide ML520/521 Chapter 2 Principles of Operation Line Feed Motor Resistance The resistance of each coil should be approximately 13 ohms. Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to th...
Page 65 - The resistance of each coil should be approximately 5 ohms.
Page: 47 Service Guide ML520/521 Chapter 2 Principles of Operation Space Motor Resistance The resistance of each coil should be approximately 5 ohms. 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 71 - The head gap is modified in .06 mm units for each range setting.
Page: 52 Service Guide ML520/521 Chapter 2 Principles of Operation 2.2.03 Head Gap MechanismThe head gap is automatically set for the thickness of the medium loaded in the printer. In the case of envelopes, where the medium thickness varies as the printhead moves along the platen, the strike force o...
Page 75 - The components of the paper feed mechanism are listed below.; Change Lever (Paper Path Selection Lever)
Page: 54 Service Guide ML520/521 Chapter 2 Principles of Operation 2.2.05 Line Feed Mechanism The line feed operation is accomplished by activating the line feed motor which turns the platen. The rotation of the platen is used to feed paper from the selected paper path. The components of the paper f...
Page 77 - As the platen turns, the platen gear causes the idle gear to rotate.
Page: 55 Service Guide ML520/521 Chapter 2 Principles of Operation Cut Sheet/Continuous Sheet Switching Mechanism Top Feed (for cut sheet paper) When cut sheet paper is used during normal operation or by the Cut Sheet Feeder (CSF) option, place the change lever in the Top Feed position. As the plate...
Page 81 - Bottom feed of continuous sheets is possible; only; when an optional pull tractor unit is installed.
Page: 58 Service Guide ML520/521 Chapter 2 Principles of Operation Continuous Paper Feed (Pull Tractor Mechanism) Bottom feed of continuous sheets is possible only when an optional pull tractor unit is installed. As the platen rotates, power is transferred to the drive gear from the line feed idler ...
Page 87 - Set the change lever to the TOP FEED position.; Wait Time; setting
Page: 63 Service Guide ML520/521 Chapter 2 Principles of Operation 2.2.08 Automatic Paper Load The Microline 520/521 printers will automatically detect cut sheet paper and feed the paper to the Top of Form (TOF) position. Cut Sheet Paper Set the change lever to the TOP FEED position. NOTE:When the c...
Page 88 - Place continuous feed paper in the appropriate tractor.
Page: 64 Service Guide ML520/521 Chapter 2 Principles of Operation Continuous Feed Paper Set the change lever to either the REAR FEED or BOTTOM FEED position. NOTE:When the change lever is in the REAR FEED or BOTTOM FEED position, the cut sheet detection lever does NOT contact the cut sheet detectio...
Page 89 - Place the change lever in the REAR FEED or BOTTOM FEED position.
Page: 65 Service Guide ML520/521 Chapter 2 Principles of Operation 2.2.09 Paper Park If continuous feed paper is installed and printing on cut sheet paper is desired, it is not necessary to unload the continuous feed paper. The Paper Park feature provides a means of retracting the continuous feed pa...
Page 90 - Chapter 3 Maintenance & Disassembly; Follow the procedures listed in; Adjustments and Service Settings; . Adjustments may be required when
Page: 66 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.1.01 General Information This section lists the parts replacement, adjustment, cleaning, lubrication, and shipping procedures. Disassembly should not be performed unless absolutely necessary. NEVER perform disassembly on a ma...
Page 93 - 20 indicates that the item is specific to the Microline 520.; the disassembly procedures for RSPL
Page: 69 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2 DISASSEMBLY/ASSEMBLY PROCEDURES General Information This section contains the printer disassembly procedures. Only the removal procedures are explained here. Reverse the procedure for the installation. At the bottom of each...
Page 96 - Pull the printhead straight up to remove it.; Refer to Section 3.3 of
Page: 71 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.02 Printhead Assembly 1. Perform this procedure: 3.2.01. 2. Open the access cover (1). 3. Lift and remove the ribbon. ( Not shown ) 4. Pull the head clamp (2) towards the right and then rotate it up to release the printhead...
Page 99 - Lift and remove the gear case assembly.; When lubricating, refer to Section 3.5 of this Service Handbook.
Page: 73 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.04 Gear Case Assembly 1. Perform these procedures: 3.2.01 , and 3.2.02 . 2. Use a straight-slot screwdriver to release the four claws (1) of the gear case assembly (2). 3. Lift and remove the gear case assembly. NOTE:Lubric...
Page 101 - Raise the front side of the upper cover assembly.; When cleaning, refer to Section 3.4 of this Service Handbook.
Page: 75 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.06 Upper Cover, Access Cover, and Sheet Guide Assemblies 1. Perform this procedure: 3.2.01. 2. Pull the platen knob (1) straight out and remove it. 3. Set the change lever (2) to the bottom feed position (toward the rear of...
Page 103 - Tilt the board to access the connectors.; Installation; The bottom sensor lever must be positioned in the SNS3 sensor (8).
Page: 76 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.07 Control Board (FJIM) 1. Perform these procedures: 3.2.01 , and 3.2.06 . 2. Remove the two screws (1). 3. Release the control board (2) from the bracket (3). 4. Tilt the board to access the connectors. 5. Detach connector...
Page 105 - Lift and remove the transformer assembly.
Page: 77 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.08 Power Supply Assembly 1. Perform these procedures: 3.2.01 and 3.2.06 . 2. Use a straight slot screwdriver to detach the claws from both sides of the cable clamp (1). 3. Remove the cable clamp (2). 4. Detach the transform...
Page 107 - Cut the nylon tie and release the cable.
Page: 78 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.09 Operator Panel PCB (LEOP) 1. Perform these procedures: 3.2.01 , 3.2.06 , and 3.2.07 . 2. Cut the nylon tie and release the cable. (Not shown) 3. Disengage the claws (1) on both sides of the frame. 4. Lift the operator pa...
Page 108 - Perform these procedures
Page: 79 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.10 PC Connector 1. Perform these procedures : 3.2.01 , 3.2.02 , and 3.2.04 . 2. Remove the two screws (1) and the connector holders. The holders are not shown. 3. Remove the PC connector (2). NOTE: Installation Do not touch...
Page 113 - Pull the space rack straight up and remove it.
Page: 82 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.13 Space Rack 1. Perform these procedures: 3.2.01 , 3.2.02 , 3.2.04 , 3.2.10 , and 3.2.11 . 2. Remove the spring (1). 3. Disengage the claws (2) on the both ends of the space rack (3). 4. Pull the space rack straight up and...
Page 116 - press too hard or the claw will break.
Page: 84 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.15 Guide Rail and Adjust Cam 1. Perform these procedures: 3.2.01 , 3.2.02 , 3.2.04 , 3.2.10 , 3.2.11 , and 3.2.14 . 2. Rotate the adjust cam (1) in the direction of arrow A as far as possible. 3. Pull the cam out and remove...
Page 119 - You may have to use a screwdriver to work the plate tabs free.; The plate must be securely seated under the claws.
Page: 86 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.17 Right Ground Plate 1. Perform these procedures: 3.2.01 , and 3.2.06 . 2. Pull the top tabs (1) of the right ground plate (2) out to free the plate from the claws of the base frame. You may have to use a screwdriver to wo...
Page 121 - Lubrication
Page: 88 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.19 Platen Assembly 1. Perform these procedures: 3.2.01 , and 3.2.06 . 2. Move the change lever (1) to the bottom feed position (to the rear of the printer). 3. Push the lock levers (2) in, then rotate them towards the front...
Page 132 - Pull the carriage shaft free of the base frame.; Cleaning; of this Service; of this Service Handbook.
Page: 94 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.25 Carriage Shaft CAUTION The space motor assembly, etc. may be left in place when removing the carriage shaft. However, use extra care when doing so. The carriage cable should be detached from the space motor before removi...
Page 136 - claw, push on the claw to move the paper pan away from the main frame.
Page: 96 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.27 Bottom Paper Sensor Levers 1. Perform these procedures: 3.2.01 , 3.2.06 , 3.2.07 , 3.2.16 , 3.2.17 , 3.2.19 , 3.2.20 , 3.2.22 , 3.2.23 , and 3.2.24 . 2. Working from the underside of the unit, release the claws of the pa...
Page 145 - should be performed when the following parts are replaced.; Procedure
Page: 101 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.3.02 Printhead Gap Adjustment General Information Before performing this adjustment, always verify that the printhead is properly installed. This adjustment should be performed when the following parts are replaced. 1. Print...
Page 146 - DO NOT DISENGAGE THE ADJUST GEAR!; Printhead Gap Modification Phase
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 gear (Figure 1 A) to Range 2 by turning the adjust screw using a small phillips screwdriver. Turn this screw slowly while moving the carriage (1) ...
Page 155 - The tables show; all; possible menu settings available with the Microline 520/521.
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 options installed. Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any u...
Page 156 - switch. This will advance the paper in micro increments.; Reset the Top of Form to Factory Default; The factory default Top of Form Setting is 1 inch.
Page: 105 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.3.05 Top of Form General Information Top of Form is the distance from the top edge of the paper to the first print position on the page. The red line on the ribbon protector indicates the baseline of the Top of Form. Setting...
Page 157 - Remove any printed pages from the printer.; Procedure: Single Sheet to Continuous Feed; Remove any single sheet pages from the printer.
Page: 106 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.3.06 Paper Park General Information Paper Park allows the user to print using single (cut) sheet pages without removing continuous forms from the printer. Procedure: Continuous Feed to Single Sheet 1. Remove any printed page...
Page 158 - To activate the Tear Feature, press TEAR.
Page: 107 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.3.07 Tear Feature NOTE: Tear is activated by pressing TEAR. It is a manual procedure. FORMS TEAR OFF is activated by changing a setting in the Menu. It is an automatic procedure. General Information This feature allows a pri...
Page 159 - DO NOT use Forms Tear Off with labels or multi-part forms.; Vertical Line Spacing Problems; Use the Micro Feed buttons to set the Top of Form.
Page: 108 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.3.08 Forms Tear Off NOTE: Tear is activated by pressing TEAR. It is a manual procedure. FORMS TEAR OFF is activated by changing a setting in the Menu. It is an automatic procedure. General Information This feature allows a p...
Page 161 - Printing the Menu provides a reference of customized settings.
Page: 109 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.3.09 Resets Reset Menu to Factory Defaults CAUTION: Once the menu has been reset, all customized menu settings will be lost. Always print the menu before resetting the printer to factory defaults. To reset the menu to factor...
Page 163 - Routine inspection and lubricating should be performed:
Page: 111 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.5 LUBRICATION 3.5.01 General Information If the lubrication procedures are not performed properly, the printer will require more frequent cleaning. Excessive lubricant attracts dust and accumulations build up quickly. An acc...
Page 164 - CAUTION; Teeth of the gears in the Gear Case Assembly
3.5.06 Areas Not Lubricated Lubricant should never contact the parts listed below. 1. Ribbon 2. Platen Assembly (Rubber Face) 3. Pressure Roller (Rubber Face) 4. Tractor Pins 5. Head Cable 6. Space Motor Printed Circuit Board 7. Electrical Contacts and Connections 8. Space Rack CAUTION Do NOT lubric...
Page 165 - Locate the original packaging or
Page: 112 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.6 SHIPPING INSTRUCTIONS 3.6.01 Return for Service CAUTION: When shipping the printer, use the original packaging to prevent damage. Be sure to secure the printhead so it will not move during shipment. 1. Locate the original ...
Page 166 - Chapter 4 Failure & Repair Analysis; When troubleshooting a defective unit, follow these steps.
Page: 113 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis 4.1.01 Introduction This section is used to isolate problems to the assembly level. Application problems and detection of faulty components on the printed circuit boards are NOT addressed. When troubleshooting a defective unit...
Page 167 - Example
Page: 114 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis 4.1.02 Printer Serial Number Identification To identify the revision level of a printer, record the serial number from the back of the printer. Refer to the following to decode the serial number. Example Printer Serial Number:...
Page 168 - At the top of the test is a header.
Page: 115 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis 4.1.03 Firmware Revision Identification To identify the revision level and part number of the firmware, print the Rolling ASCII Test or the Font Test. Refer to Section 4.8 of this Service Handbook for information on printing t...
Page 170 - Your cooperation is greatly appreciated. Thank you for your help!
Page: 117 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis 4.2.02 Problem Lists Technicians frequently request a list of common problems specific to a product. Technical Training Kits are written before a product is shipped to customers. Therefore, such information is NOT available wh...
Page 172 - Okilink II
Page: 119 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis 4.3 TROUBLESHOOTING UPDATES 4.3.01 General Information Okidata distributes updated troubleshooting information in three ways. Okilink II Faxable Facts Technical Service Bulletins 4.3.02 Okilink II Okilink II is Okidata's Bulle...
Page 173 - Has the ribbon been replaced as recommended?
Page: 120 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis 4.4 TROUBLESHOOTING TIPS 4.4.01 Preliminary Checks 1. Is the product being operated under the proper ambient conditions? 2. Does the paper being used meet the specifications for this product? 3. Has the ribbon been replaced as...
Page 176 - Make sure that the paper you are using is within specifications.; Paper specifications can be found in
Page: 123 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis 4.4.04 Tips for Preventing Image Problems 1. Make sure that the ribbon is not "dried out". If the printer output is faded, install a new ribbon, then print another sample. 2. Make sure that the paper you are using is w...
Page 177 - Nothing happens when the unit is powered on.
Page: 124 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis 4.4.05 Common Problems 1. Nothing happens when the unit is powered on. The unit may not be plugged in. Check the power cord connection to the outlet and to the printer. If a power strip is being used, make sure that it is powe...
Page 178 - Always power OFF the printer before you turn the platen knob.
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 software manufacturer to see if they have added any additional drivers since you purchased your software. If you have embedded any printer commands in you...
Page 181 - the cause of the binding.
2. Defective platen. Replace the platen. Smeared Print Possible Causes: 1. Ribbon protector is missing or broken. Replace the ribbon protector. 2. Verify that the headgap menu setting is appropriate for the type of paper being used. 3. Check / perform the printhead gap adjustment. 4. Paper is not wi...
Page 182 - Drifting Margin; Refer to the next section and / or Technical Service Bulletin 3309.
Drifting Margin Possible Causes: 1. Power OFF the printer. Move the carriage assembly. The carriage should move smoothly. If it does not, remove the cause of the binding. 2. Refer to the next section and / or Technical Service Bulletin 3309. Copyright 1997, Okidata, Division of OKI America, Inc. All...
Page 183 - MUST BE
Page: 126 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Left Margin Drifting Problem NOTE: This information is also provided in Technical Service Bulletin 1707. To correct a problem with the left margin drifting during print operations, follow this procedure. 1. Manually slide the ...
Page 184 - Follow these guidelines when using the Troubleshooting Tables.
Page: 127 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis 4.6 FAULT ALARMS 4.6.01 General Information Follow these guidelines when using the Troubleshooting Tables. CAUTION: Always check that all connectors on the printer are making good contact. 1. Record the status (OFF, solidly ON...
Page 187 - Space Motor Alarm
Page: 129 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis 4.6.03 ALARM/LED Display Troubleshooting Tables CAUTION: Always check that all connectors on the printer are making good contact. Reference Number Failure Description Cause Recommended Action 1 Space Motor Alarm Space motor IP...
Page 189 - When using the Repair Analysis Procedures, follow these steps.
Page: 130 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis 4.7 REPAIR ANALYSIS PROCEDURES (RAPs) 4.7.01 Using the RAPs When using the Repair Analysis Procedures, follow these steps. 1. Go to the RAP Index. 2. Find the RAP which is associated with the printers problem. 3. Go to the app...
Page 207 - (Refer to Appendix A of this Service
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 RS232C board. Has the problem been resolved? Yes End of procedure. No Contact Technical Support. No Replace the main control board. Has the problem be...
Page 211 - Utility 10 cpi; Follow these steps to print the font test.
Page: 145 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis 4.8.03 Font Test General Information The font test is a one page sample printout of each available typeface. HSD 10 cpi HSD 12 cpi HSD 17.1 cpi Utility 10 cpi Utility 12 cpi Utility 17.1 cpi NLQ 10 cpi NLQ 12 cpi NLQ 10 cpi Do...
Page 215 - The printer has the following cable requirements.
Page: 147 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Serial Cable Information The information in this section will help you make a serial cable to connect between the printer and computer. Refer to the computer documentation to determine the cable requirements on the computers e...
Page 220 - Layout Diagram
Page: 152 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Layout Diagram 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 226 - Chapter A Reference Charts
Page: 158 Service Guide ML520/521 Chapter A Reference Charts Board Layout 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 227 - NONE; SNS2: Bottom Feed Paper Out Sensor
Page: 159 Service Guide ML520/521 Chapter A Reference Charts A.2.01 Main Controller Board (FJIM) Function The main controller board contains a microprocessor, EPROM, EEPROM, drive circuitry, 128 Kbyte DRAM, sensors and interface connector. The AC voltages from the power supply are rectified and regu...
Page 229 - SHIFT
Page: 160 Service Guide ML520/521 Chapter A Reference Charts A.2.02 Operator Panel Board (LEOP) Function The operator panel control LSI send commands to the microprocessors serial I/O port whenever the operator panels switches are pressed. The operator panel LED display provides information on fault...
Page 231 - Transformer secondary voltages
Page: 161 Service Guide ML520/521 Chapter A Reference Charts A.2.03 Power Supply Assembly Function The power supply board is comprised of a noise filter board and transformer. The power supply board provides AC voltages to the main controller board via CN-3. Firmware NONE Fuses F1: 125/250V 2.5 amp....
Page 233 - Photosensor: used to monitor space motor movement.
Page: 162 Service Guide ML520/521 Chapter A Reference Charts A.2.04 Space Motor Board Function The space motor board contains an encoder disk and photosensor. The encoder disk and the photosensor generate phase signals. These signals governs the speed and direction of the space motor via the LSI and...
Page 235 - Masked to the MPU: Socket is empty
Page: 163 Service Guide ML520/521 Chapter A Reference Charts A.2.05 RS232-C Serial Interface Board - Option (LXHI) Function This board provides you serial interface capabilities. The serial interface parameters can be set through the printer menu. Firmware Masked to the MPU: Socket is empty Fuses NO...
Page 237 - Chapter B Illustrated Parts Listing; Locate the part and its part number in this section.
Page: 164 Service Guide ML520/521 Chapter B Illustrated Parts Listing B.1 OVERVIEW - B.1.01 General Information This appendix will assist you in identifying the assemblies and parts of the product. Use Section Four (Failure Analysis) to determine the defective part(s). Locate the part and its part n...
Page 238 - N/A will appear where a part number is not available.
Page: 165 Service Guide ML520/521 Chapter B Illustrated Parts Listing Format The format for this appendix is a series of tables with diagrams. The tables contain the item reference number, the Okidata and Oki-Japan (Oki-J) part numbers, the part description, a comments section, and the disassembly p...
Page 241 - Both
information updates. Okidata distributes the TSBs through Okilink II. The TSBs are issued monthly. 520 This part is specific to the Microline 520 printer. 521 This part is specific to the Microline 521 printer. Both This part is used by both the Microline 520 and Microline 521 printers. Copyright 19...
Page 243 - Below is an index to the illustrated parts breakdown charts.; Section Description
Page: 169 Service Guide ML520/521 Chapter B Illustrated Parts Listing B.2 CHARTS Below is an index to the illustrated parts breakdown charts. Section Description B.2.01 Printer B.2.02 Upper Cover Assembly B.2.03 Printer General Assembly B.2.04 Printer Unit (1 of 3) B.2.05 Printer Unit (2 of 3) B.2.0...
Page 245 - Item; Description
Page: 171 Service Guide ML520/521 Chapter B Illustrated Parts Listing B.2.01 Printer Part numbers are subject to change. Refer to Okilink II for current part numbers and pricing information. Item Okidata P/N Oki-J P/N Description Comments Refer to B.1.02 Disassembly Procedure 1 62409001 N/A Printer:...
Page 248 - RSPL Both
Page: 173 Service Guide ML520/521 Chapter B Illustrated Parts Listing B.2.03 Printer General Assembly Item Okidata P/N Oki-J P/N Description Comments Refer to B.1.02 Disassembly Procedure 1 53562601 2PP4094-6507P3 Knob: Platen (ML500 Series) RSPL Both 3.2.06 2 53067301 2PP4094-6506P1 Cover: (B) for ...
Page 261 - Option RSPL Both
Page: 179 Service Guide ML520/521 Chapter B Illustrated Parts Listing B.2.09 Option Parts Item Okidata P/N Oki-J P/N Description Comments Refer to B.1.02 Disassembly Procedure 1 50097901 N/A Tractor: Pull and Bottom Assembly (Right) Option RSPL Both N/A 2 50098001 4PA4025-3608G1 Tractor: Pull and Bo...
Page 265 - Document Both
Page: 182 Service Guide ML520/521 Chapter B Illustrated Parts Listing B.2.12 Documentation Item Okidata P/N Oki-J P/N Description Comments Refer to B.1.02 Disassembly Procedure 1# 58229401 N/A Kit: ML520/521 Service Training Document Both N/A 1# 58229402 N/A Kit: ML520/521 Service Training Document ...
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