Page 1 300 dpi, which is ideal for printing, but does not view on most displays well. Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)
Page 2: Table Of Contents
Table of Contents Service Guide ML520/521 0 About This Manual Front Cover Copyright Information 1 Product Specifications 1.1.01 General Information ...1.2 Physical Specifications ...1.3 Power Requirements ...1.4 Environmental Conditions ...1.5 Agency Approvals ...1.6 Operational Specifications ...1.7 Paper Specifications ...1.8 Memory Specifications ...1.9 Consumables...
Page 3 Table of Contents ...Head Drive Time ...Print Speed ...%Head Overheat Alarm Processing ...2.1.08 Power Supply Circuit 2.2 Mechanical Operation - Printhead Mechanism ...Printhead Gap Information ...Interconnect Diagram: Control Board to Printhead ...Line Feed Motor Resistance ...Space Motor Resistance ...Printhead Operation ...Printhead Temperature ...2.2.02 Spacing Mechanism ...Spacing Operation...
Page 4 Table of Contents ...3.2.11 Space Motor and Roller Guide Assemblies ...3.2.12 Carriage Cable ...3.2.13 Space Rack ...3.2.14 Roller/Holder Backup Assembly ...3.2.15 Guide Rail and Adjust Cam ...3.2.16 Left Ground Plate ...3.2.17 Right Ground Plate ...3.2.18 Rear and Cut Sheet Paper Feed Sensor Levers ...3.2.19 Platen Assembly ...3.2.20 Paper Chute Assembly ...3.2.21 Line Feed Motor Assembly...
Page 5 Table of Contents ...4.4.04 Tips for Preventing Image Problems ...4.4.05 Common Problems 4.5 Abnormal Output - Output Samples ...Left Margin Drifting Problem 4.6 Fault Alarms ...4.6.02 ALARM/LED Display Troubleshooting Table Index ...4.6.03 ALARM/LED Display Troubleshooting Tables 4.7 Repair Analysis Procedures (Raps) ...4.7.02 RAP Index ...RAP 01 No Power Supplied to Printer ...RAP 02 No Spacing Operation...
Page 6 Table of Contents ...Format ...Current Part Numbers ...B.1.02 Definition of Terms ...B.1.03 Parts Ordering Information B.2 Charts ...Overview ...B.2.01 Printer ...B.2.02 Upper Cover Assembly ...B.2.03 Printer General Assembly ...B.2.04 Printer Unit ...B.2.05 Printer Unit ...B.2.06 Printer Unit ...B.2.07 Carriage Assembly ...B.2.08 Options ...B.2.09 Option Parts ...B.2.10 Consumables...
Page 7: About This Manual
Oki Electric Industry Company, Ltd. OkiSmart Paper Handling is a trademark of Oki Electric Industry Company, Inc. PLUG n PRINT is a registered trademark of Oki America, Inc.; marque deposee de Oki America, Inc. Bitstream is a registered trademark of Bitstream Incorporated.
Page 8 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://bpx.okidata.com)
Page 9: Product Specifications
2. OkiSmart Panel Emulator 3. OkiSmart Setup Refer to the Printer Handbook for more information. Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)
Page 10: Physical Specifications
1.2.02 Printer Weight Microline 520 17.6 pounds (8.0 kilograms) Microline 521 23.1 pounds (10.5 kilograms) Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)
Page 11: Power Requirements
1.3.03 Power Frequency 120 VAC: 60 Hz +/- 2% 230/240 VAC: 50/60 Hz +/- 2% Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)
Page 12: Environmental Conditions
While in storage: 14 to 122 degrees Fahrenheit ( - 10 to 50 degrees Celsius) Storage humidity: 5% to 95% RH Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)
Page 13: Agency Approvals
FCC: FCC Certified per Part 15, Subject J, Class B IEC: IEC 950 VDE: VDE 0805 VDE 0875 Class B BS: BS 7002 Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)
Page 14: Operational Specifications
Print Speed at Different CPI for the ML 520/521 Mode 17.1 Utility 17.1 17.1 1.6.02 Characters Per Line Microline 520 Service Guide ML520/521 Chapter 1 Product Specifications Utility 320 (12cpi) 9 x 7 Horiz. DPI High Speed Draft 427 (12cpi) 7 x 7 Vert.
Page 15 Characters Per Line Microline 521 Characters Per Line 1.6.03 Character Pitches 5, 6, 8.5, 10, 12, 15, 17.1, 20 1.6.04 Character Sets Standard ASCII EPSON Character Set I & II IBM Character Set I, II & All Characters Foreign Character Substitution International Character Sets Code Page 850, 860, 863, 865 and 437 Line Graphics...
Page 16 1.6.05 Emulations NOTE: The emulations are co-resident Epson FX IBM Proprinter Microline Standard 1.6.06 Fonts Near Letter Quality Courier Utility Gothic High Speed Draft Gothic Bar Code Code 39 UPC A UPC E EAN 8 EAN 13 Interleaved 2 of 5 Code 128 (A, B, C) Postnet 1.6.07 Front Panel Switches...
Page 17 RS232C Serial 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/72 inch n/144 inch n/216 inch 1.6.11 Line Feed Time 65 milliseconds 6 lines per inch (lpi) 6 milliseconds 8 lines per inch (lpi) 1 second 5.0 inches (Continuous paper feed rate) 1.6.12 Menu Mode...
Page 18 Paper Park Automatic Paper Loading Forms Tear Off 1.6.15 Paper Loading Auto Loading (Top Feed) Press FORM FEED / Load switch to feed paper to default position 1.6.16 Paper Out Detection Distance from end of paper Rear Feed: 0.5 inches (12.7 mm) Bottom Feed: 0.5 inches (12.7 mm) Top Feed: 0.5 inches (12.7 mm) 1.6.17 Paper Tear Capabilities...
Page 19 1. Printhead Gap Adjustment This is a SERVICE ADJUSTMENT made by a technician. It is covered in Section 3.3 of this Service Handbook. The Adjustment measures 0.014 +/- 0.001 inches 90.35, +/-0.03 mm). 2. Printhead Gap Adjustment This is a MENU ITEM in the SET-UP Group. It fine tunes the automatic setting of the printhead gap.
Page 20 Mode Near Letter Quality Speed Matrix (H x V) 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) Utility 80 (12 cpi) 320 (12 cpi)
Page 21: Paper Specifications
Feed Paper Feed Path: Rear or Bottom Refer to the Printhead Gap Information, Section 1.6 Printhead Gap Information: Cut Sheet Weight: 12 to 24 lbs. (45 to 90 g/m 2 ) Service Guide ML520/521 Chapter 1 Product Specifications Page: 9...
Page 22 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 (18.2 to 36.3 centimeters) Length: 3 to 17 inches (7.62 to 43.18 centimeters) Thickness: 0.014 inches (0.325 millimeters) Maximum Paper Feed Path: Top Printhead Gap Information: Refer to the Printhead Gap Information, Section 1.6.
Page 23 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 520 7.2 to 8.5 inches (18.2 to 21.5 centimeters) Microline 521 7.2 to 14.3 inches (18.2 to 36.3 centimeters) Length: 3 to 17 inches (7.62 to 43.18 centimeters) Thickness: 0.14 inches (0.36 millimeters) Paper Feed Path: Top...
Page 24 Maximum: 16.5 inches (41.9 centimeters) Printing Area Microline 520 8 inches Maximum Microline 521 13.6 inches Maximum 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 25: Memory Specifications
Settings are: 64 K, 32 K, 1 line Print Buffer DLL Buffer Scratch Pad 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) Service Guide ML520/521 Chapter 1 Product Specifications...
Page 26: Consumables
Life (On average, at 10 characters per inch, Utility Mode) 4 million characters Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com) Service Guide ML520/521...
Page 27: Options - Cut Sheet Feeders
Dual Bin with envelope capability Paper Width: 7.2" to 14.3" (18.3 cm to 36.3 cm) Paper Length: 10.1" to 14" (25.6 cm to 35.6 cm) Capacity: 170 sheets (16 lb.), 100 sheets (20 lb.) Service Guide ML520/521 Chapter 1 Product Specifications Page: 12...
Page 29: Pull Tractor Kit
The Pull Tractor Kit (P/N 70023201) is a wide feeder for the Microline 521. Bottom Feed Rear Feed (For Push/Pull Operation) Paper Types: Continuous Feed and Labels 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 30: Bottom Push Tractor Kit
The Bottom Push Tractor Kit (P/N 70023101) is a wide feeder for the Microline 521. Bottom Feed Paper Type: Continuous Feed Includes: Stand and Metal Tear Bar 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 31: 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 OKIDATA Business Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)
Page 32: Roll Paper Stand
Adapts printer for use with roll-type paper (Model 520 only) Includes: Stand, Support, Cord and DIN plug for connection to printer 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 33: Okismart Typer Utility
2. OKISmart Panel Emulator 3. OKISmart Setup Refer to the Printer Handbook for more information. 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 34: Reliability
Approximately 4 million characters 1.11.06 Warranty (Limited) One year, parts and labor 1.11.07 Service Authorized OKIDATA Service Centers 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 35: Principles Of Operation
Operator Panel Space Motor / Line Feed Motor Printhead 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) Service Guide ML520/521 Chapter 2 Principles of Operation...
Page 36 The microprocessor controls the entire printer by executing the control program through LSIs and the driver circuits. 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 37: Block Diagram
Page: 21 Service Guide ML520/521 Chapter 2 Principles of Operation Block 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 38: Program Rom
The Program ROM is assigned to the program memory area of the MPU and instructions are fetched by the PSEN signal of the MPU. 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 39: Ram
The RAM is CMOS dynamic RAM with 65,536 words x 16-bit configuration. It is used as a receive buffer, print buffer and work buffer. 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 40: Lsi
Controls the external interface. The LSI is connected to the MPU. 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 41: Electrically Erasable Programmable Read Only Memory
1,024 bits. The EEPROM contains the menu data and the head drive time correction data. 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 42: Initialization
SELECT lamp to indicate that the printer is in the ON-LINE state. 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 43: Parallel Interface Control
When the buffer is full and reception is not desired, the BUSY signal is sent to request data transmission be stopped. 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 44: Print Control
In the case of envelopes, where the medium thickness varies as the printhead moves along the platen, the strike force of the pins changes to compensate for the differences in thickness. 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 45: Lsi/Printhead Interface
The logic circuit of the printhead signals the LSI if a parity error is detected in the print data. 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 46: Gap Adjust Control
Refer to Section 2.2.03 for a description of the mechanical process. All values in the below chart are in millimeters 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 47: Print Compensation Control
The printhead compensates for the shape of the platen as shown below. NOTE: Also refer to Section 2.1.07 - Head Drive Time 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 48: Space And Line Feed (Sp/Lf) Motor Control
MPU. These signals are sent to the SP/LF motor driver. 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 49: Line Feed Motor Control
The serial data from the LSI (04B: MSM79V035) is processed by a register contained in the SP/LF motor driver to measure the overdrive time and to change the phase. 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 50: Space Motor Control
After comparing the target speed for each print mode with the actual speed, the motor is accelerated or decelerated to maintain the desired speed for each print mode. 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 51: Encoder Disk
(the frequency division is based on the selected print pitch) to generate the signal IPT. The IPT signal provides dot-on timing and carriage position detection timing. 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 52: Operation Panel
Page: 36 Service Guide ML520/521 Chapter 2 Principles of Operation 2.1.06 Operation Panel The Serial I/O Port (Ports 20 - 23) of the MPU reads the operation panel switch data from the operation panel control LSI (Location IC1: BUS148S). A two byte (15 bits +1 parity bit (even parity)) command (OPTXD) is transmitted from the MPU to the operation panel LSI in synchronization with the OPCLK signal.
Page 54: Alarm Circuit
This signal becomes the ALM signal. The ALM signal is sent to the power supply board and causes the DC voltages to be turned off. 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 55: Low Motor Drive Voltage Alarm
R544, then input to the A/D port of the MPU. The value of this voltage is used to control the drive time and the print speed (pass number) of the head. 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 56: Head Drive Time
By monitoring the voltage drop every 500 microseconds, the MPU is able to control and maintain the impact necessary for each printhead pin. 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 57: Print Speed
+32 vdc to +34 vdc +30 vdc to +32 vdc +30 vdc or less 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) Service Guide ML520/521...
Page 58: Head Overheat Alarm Processing
The voltage of the TSD signal is monitored at the MPU A/D port to control the pass number and print method (uni-directional / bi-directional) at each of seven levels. 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 59: Power Supply Circuit
Serial interface line voltage and the printhead analog circuit +40 vdc Printhead, space motor and line feed motor drive voltage 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) Service Guide ML520/521...
Page 60 Printed Circuit Board Logic Control, Print Driver, Analog Sensor Control and Thermistor Cooling Fin 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) Service Guide ML520/521...
Page 61: Printhead Gap Information
An explanation of each setting follows. Auto Gap This is the factory default. Automatically determines paper thickness of the first page. During single-sheet feed, each pages thickness is checked while a job is printing. Service Guide ML520/521 Chapter 2 Principles of Operation Page: 44...
Page 62 Bypasses the automatic head gap adjustment. 1 is the narrowest gap setting. 9 is the widest gap setting. 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 63: Interconnect Diagram: Control Board To Printhead
The printhead coil resistance values ARE NOT LISTED. The individual printwire control lines CANNOT be accessed on this printhead. 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 64: Line Feed Motor Resistance
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 this material. (http://bpx.okidata.com)
Page 65: Space Motor Resistance
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 material. (http://bpx.okidata.com)
Page 66: Printhead Operation
Page: 48 Service Guide ML520/521 Chapter 2 Principles of Operation Printhead Operation When the printhead is idle, the armature is attracted to the permanent magnet. The print wires, which are attached to each armature, are then concealed inside the wire guide.
Page 68: Printhead Temperature
The voltage of the TSD signal is monitored at the MPU A/D port to control the pass number and print method (uni-directional / bi-directional) at each of seven levels. 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 69: Spacing Mechanism
Encoder Disk Carriage Frame Carriage Shaft Space Rack 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) Service Guide ML520/521 Chapter 2 Principles of Operation...
Page 70: Spacing Operation
In the same way, the rotation of the space motor can be recognized and controlled by measuring the phase relationship and the pulsewidth of the signals generated by the photosensors. 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 71: Head Gap Mechanism
Page: 52 Service Guide ML520/521 Chapter 2 Principles of Operation 2.2.03 Head Gap Mechanism The 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 of the pins changes to compensate for the differences in thickness.
Page 73: Ribbon Drive Operation
Although the space motor moves in both the forward and reverse directions during bi-directional printing, the gears in the ribbon drive assembly maintain uni-directional ribbon feed by switching the rotation direction of the gears. Service Guide ML520/521 Chapter 2 Principles of Operation Page: 53...
Page 75: Line Feed Mechanism
The movement of the front release gear arm changes the position of the front release gear shaft. This causes the front pressure roller to open or close. The movement of the release cam causes the rear pressure roller to open or close. Service Guide ML520/521 Chapter 2 Principles of Operation Page: 54...
Page 77: Cut Sheet/Continuous Sheet Switching Mechanism
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.
Page 79: Cut Sheet Paper Feed Operation
When using cut sheet paper, the change lever must be in the TOP position so the platen and pressure rollers can feed the paper. This also disengages the push tractor. 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 80: Continuous Paper Feed (Rear Tractor Mechanism)
The tractor gear drives the pin tractor belts, which feed the continuous paper. 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 81: Continuous Paper Feed (Pull Tractor Mechanism)
B and idler gear A. The drive gear turns the pull tractor assembly, which feeds the continuous paper. 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 82: Continuous Paper Feed (Bottom Tractor Feed
The drive gear turns the pin tractor belts on the bottom tractor feed unit, which feeds the continuous paper. 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 83 This mechanism consists of an optional pull tractor and a standard push tractor mechanism. Continuous paper is fed by these two tractors at the same time. 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 84: Paper Detection Mechanism
Page: 61 Service Guide ML520/521 Chapter 2 Principles of Operation 2.2.06 Paper Detection Mechanism Top Feed Paper Detection When cut sheet paper is inserted into the printer, Point A of the Rear/Top Paper Feed Lever is pushed backward, causing the Sensor Lever to rotate.
Page 86: Support Protector Mechanism
5 mm from the left bracket. 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 87: Automatic Paper Load
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 88: Continuous Feed Paper
The line feed motor will feed the paper until the leading edge of the paper reaches the top of form position. 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 89: Paper Park
This operation may be useful when length of the paper to be parked is greater than 19 inches. 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 90: Maintenance & Disassembly 3.1.01 General Information
Proper performance of maintenance and cleaning will help to achieve the best possible print quality from the printer. 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 91: Maintenance Tools
Clean, soft, and lint-free Cloth All-Purpose Cleaner Contact Kleen (Okidata P/N 51802301) Platen Cleaner Machine Grease Machine Oil 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 92: Maintenance Precautions
Guide Rail (3.2.15) Platen Assembly (3.2.19) Carriage Shaft (3.2.25) 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) Service Guide ML520/521 Chapter 3 Maintenance & Disassembly (Refer to Section 3.3 of this Service...
Page 93: Disassembly/Assembly Procedures
Be sure to read all notes, cautions, and warnings, as they contain important information regarding disassembly / assembly. 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 94: Preliminary Items
P/N 70000803 Kit: Parallel Interface Option Both B.2.08 Plug n Play Accessory P/N 70012801 Kit: RS232-C Serial Interface Option Both B.2.08 Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Service Guide ML520/521 Chapter 3 Maintenance & Disassembly...
Page 95 Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)
Page 96: Printhead Assembly
Page: 71 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.02 Printhead Assembly 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 (3).
Page 98: Ribbon Protector
4. Lift the ribbon protector (4) straight up and remove it. P/N 53562801 Protector: Ribbon RSPL Both B.2.07 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 99: Gear Case Assembly
When lubricating, refer to Section 3.5 of this Service Handbook. P/N 51228501 Gear: Case (Assembly) RSPL Both B.2.07 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) Service Guide ML520/521 Chapter 3 Maintenance &...
Page 100: Pull-Up Roller Assembly
P/N 53341501 Roller: Pull Up Assembly (Narrow) RSPL 520 B.2.05 P/N 53341601 Roller: Pull Up Assembly (Wide) RSPL 521 B.2.05 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) Service Guide ML520/521 Chapter 3 Maintenance &...
Page 101: Upper Cover, Access Cover, And Sheet Guide
(middle) setting. If the lever is not correctly positioned, the ALARM lamp will light and the unit will not automatically load paper or receive data. When cleaning, refer to Section 3.4 of this Service Handbook. Service Guide ML520/521 Chapter 3 Maintenance & Disassembly Page: 75 (3.2.07).
Page 102 P/N 53067301 Cover: (B) for card slot RSPL Both B.2.03 P/N 53562601 Knob: Platen (ML500 Series) RSPL Both B.2.03 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 103 Page: 76 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.07 Control Board (FJIM) 3.2.01 , and 3.2.06 . 1. Perform these procedures: 2. Remove the two screws (1). 3. Release the control board (2) from the bracket (3). 4. Tilt the board to access the connectors.
Page 104 P/N 55072401 PCB: FJIM (w/o ROM) RSPL Both B.2.03 P/N 55938301 IC: EEPROM BR93CC46A RSPL Both B.2.03 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 105: Power Supply Assembly
Page: 77 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.08 Power Supply Assembly 3.2.01 and 3.2.06 . 1. Perform these procedures: 2. Use a straight slot screwdriver to detach the claws from both sides of the cable clamp (1).
Page 106 P/N 56306201 Fuse: 1A 250V (Filter Brd 220V) Option RSPL Both B.2.03 P/N 56306101 Fuse: 2.5A 125V (Filter Board) RSPL Both B.2.03 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 107: Operator Panel Pcb (Leop)
P/N 53562703 Panel: Operator RSPL Both B.2.03 P/N 55937502 PCB: LEOP (Operator Panel) RSPL Both B.2.03 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) Service Guide ML520/521 Chapter 3 Maintenance &...
Page 108: Pc Connector
Page: 79 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.10 PC Connector procedures: 3.2.01 , 3.2.02 , and 3.2.04 . 1. Perform these 2. Remove the two screws (1) and the connector holders. The holders are not shown. 3. Remove the PC connector (2).
Page 109 P/N 56729601 Connector: PC HD40 RSPL Both B.2.07 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 110: Space Motor And Roller Guide Assemblies
Page: 80 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.11 Space Motor and Roller Guide Assemblies 3.2.01 , 3.2.02 , 3.2.04 , and 3.2.10 . 1. Perform these procedures: 2. Remove the three screws (1). 3. Lift the space motor assembly (2).
Page 111 P/N 53342001 Holder: Guide Roller RSPL Both B.2.07 P/N N/A Pin Both B.2.07 P/N N/A Guide Roller Spring Both B.2.07 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 112 P/N 56627301 Cable: Carriage (Narrow) RSPL 520 B.2.07 P/N 56627302 Cable: Carriage (Wide) RSPL 521 B.2.07 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) Service Guide ML520/521 Chapter 3 Maintenance &...
Page 113: Space Rack
Page: 82 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.13 Space Rack 3.2.01 , 3.2.02 , 3.2.04 , 3.2.10 , and 3.2.11 . 1. Perform these procedures: 2. Remove the spring (1). 3. Disengage the claws (2) on the both ends of the space rack (3).
Page 114 P/N 53563301 Rack: Space (Narrow) RSPL 520 B.2.04 P/N 53563401 Rack: Space (Wide) RSPL 521 B.2.04 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 115: Roller/Holder Backup Assembly
P/N N/A Pin Both B.2.07 P/N 50925001 Backup Roller Holder Spring Both B.2.07 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) Service Guide ML520/521 Chapter 3 Maintenance &...
Page 116: Guide Rail And Adjust Cam
Page: 84 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.15 Guide Rail and Adjust Cam 3.2.01 , 3.2.02 , 3.2.04 , 3.2.10 , 3.2.11 , and 3.2.14 . 1. Perform these procedures: 2. Rotate the adjust cam (1) in the direction of arrow A as far as possible.
Page 117 P/N 51009901 Guide: Rail (Wide) RSPL 521 B.2.04 P/N 53067701 Cam: Adjust RSPL Both B.2.04 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 118: Left Ground Plate
3. Work the left ground plate (1) up, and then out, to remove it. P/N 51010301 Plate: Left Ground RSPL Both B.2.04 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) Service Guide ML520/521 Chapter 3 Maintenance &...
Page 119: Right Ground Plate
Installation The plate must be securely seated under the claws. P/N 51010201 Plate: Right Ground RSPL Both B.2.05 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) Service Guide ML520/521 Chapter 3 Maintenance &...
Page 120: Rear And Cut Sheet Paper Feed Sensor Levers
P/N 50804902 Lever: Sensor RSPL Both B.2.04 P/N 50804801 Lever: Rear Sensor RSPL Both B.2.04 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) Service Guide ML520/521 Chapter 3 Maintenance &...
Page 121: Platen Assembly
Page: 88 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.19 Platen Assembly 3.2.01 , and 3.2.06 . 1. Perform these procedures: 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 to unlock them from the frame.
Page 122 P/N 50098301 Platen Assembly (Narrow) RSPL 520 B.2.05 P/N 50098302 Platen Assembly (Wide) RSPL 521 B.2.05 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 123: Paper Chute Assembly
Page: 89 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.20 Paper Chute Assembly 3.2.01 , 3.2.06 , and 3.2.19 . 1. Perform these procedures: 2. Remove the rear pressure roller (1). 3. Use a straight slot screwdriver to release the claws of the lock spring (2) and remove the spring.
Page 125: Line Feed Motor Assembly
Page: 90 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.21 Line Feed Motor Assembly 3.2.01 , 3.2.06 , 3.2.07 , 3.2.16 , 3.2.19 , 3.2.20, and 3.2.21 (this 1. Perform these procedures: section). 2. Firmly press down on the line feed motor assembly (1) while tilting the assembly out.
Page 126 P/N 56627201 Cord: Connection Line Feed RSPL Both B.2.04 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 127: Reset Spring
4. While pressing up, slide the spring out (in the direction of Arrow B) and remove it. P/N 50923201 Spring: Reset RSPL Both B.2.05 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) Service Guide ML520/521 Chapter 3 Maintenance &...
Page 128: Idle Gear And Change Lever
Page: 92 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.23 Idle Gear and Change Lever 3.2.01 , 3.2.06 , 3.2.07 , 3.2.16 , 3.2.17 , 3.2.19 , 3.2.20 , and 1. Perform these procedures: 3.2.22 . 2. Remove the idle gear (1). The idle gear is a large narrow gear.
Page 129 P/N 50805101 Lever: Change RSPL Both B.2.05 P/N 51228201 Gear: Idle RSPL Both B.2.05 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 130: Pressure Spring
Page: 93 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.24 Pressure Spring 3.2.01 , 3.2.06 , 3.2.07 , 3.2.16 , 3.2.17 , 3.2.19 , 3.2.20 , 1. Perform these procedures: 3.2.22, and 3.2.23 . 2. Turn the front release gear arm (1) until it is disengaged.
Page 131 P/N 50923401 Spring: Pressure (Wide) RSPL 521 B.2.06 P/N 51228301 Arm: Front Release Gear RSPL Both B.2.06 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 132: Carriage Shaft
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 removing the carriage shaft.
Page 133 P/N 53563501 Shaft: Carriage (Narrow) RSPL 520 B.2.04 P/N 53563502 Shaft: Carriage (Wide) RSPL 521 B.2.04 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 134: Leaf Spring
7. Remove the spring. P/N 50923001 Spring: Leaf (Narrow) RSPL 520 B.2.04 P/N 50923101 Spring: Leaf (Wide) RSPL 521 B.2.04 Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.01 , 3.2.06 , 3.2.07 , 3.2.16 , and 3.2.25 .
Page 135 Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)
Page 136: Bottom Paper Sensor Levers
P/N 50097301 Pan: Paper (Narrow) RSPL 520 B.2.06 P/N 50097401 Pan: Paper (Wide) RSPL 521 B.2.06 P/N 50804601 Lever: Bottom Paper End RSPL Both B.2.04 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.01 , 3.2.06 , 3.2.07 , 3.2.16 , 3.2.17 , 3.2.19 , 3.2.20 ,...
Page 137 P/N 51227801 Shaft: Front Release Gear RSPL 520 B.2.06 (Narrow) P/N 51227901 Shaft: Front Release Gear (Wide) RSPL 521 B.2.06 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 138: Front Pressure Roller Assembly
P/N 50922801 Spring: Front Pressure (Wide) RSPL 521 B.2.06 P/N 53341101 Holder: Front Roller RSPL Both B.2.06 P/N 53341202 Roller: Front Pressure RSPL Both B.2.06 Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.01 , 3.2.06 , 3.2.07 , 3.2.16 , 3.2.17 , 3.2.19 , 3.2.20 ,...
Page 139 Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)
Page 140: Tractor Assembly
The left tractor assembly must be positioned to the left (line feed motor side) of the plastic tab and Lubrication When lubricating, refer to Section 3.5 of this Service Handbook. ground plate. Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.2.01 , 3.2.06 , 3.2.07 , 3.2.16 , 3.2.17 , 3.2.19 , 3.2.20 ,...
Page 141 P/N 50097501 Tractor: Assembly (Narrow) RSPL 520 B.2.06 P/N 50097502 Tractor: Assembly (Wide) RSPL 521 B.2.06 P/N 51228001 Gear: Change RSPL Both B.2.05 P/N 51228101 Gear: Tractor RSPL Both B.2.05...
Page 143: Main Frame
P/N 53563101 Frame: Main (Narrow) RSPL 520 B.2.04/5/6 P/N 53563201 Frame: Main (Wide) RSPL 521 B.2.04/5/6 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) Service Guide ML520/521 Chapter 3 Maintenance &...
Page 144: Printer Adjustments
Failure to perform these procedures may result in unnecessary service calls. 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 145: Printhead Gap Adjustment
The adjust cam lever is moved to ensure the printhead moves parallel to the platen. 4. Verification Phase Steps 13 -14 Verifies that the parallel adjustment phase did not affect the printhead gap modification phase. Procedure Setup Phase Service Guide ML520/521 Chapter 3 Maintenance & Disassembly Page: 101...
Page 146 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.
Page 148: Key Combinations
(Hold during Power-ON) SEL + FF/LOAD (Hold during Power-ON) 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) Service Guide ML520/521 Chapter 3 Maintenance & Disassembly Description Reset Menu to Factory Defaults.
Page 149: Menu Operation
Page: 103 Service Guide ML520/521 Chapter 3 Maintenance & Disassembly 3.3.04 Menu Operation General Information The menu is used to customize the printers settings and features. The Menu is made up of a number of Groups. Each Group has a list of Items.
Page 150 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. If the printer was selected, the SELECT lamp will light. When in Menu Mode, the functions printed below the operator panel switches are active. 6.
Page 151 9. Press SET until FULL OPERATION prints. 10. Press EXIT to save the change and exit Menu Mode. 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 152 Zero Character Code Page Rear Feed Line Spacing Form Tear-Off Skip Over Perforation Service Guide ML520/521 Chapter 3 Maintenance & Disassembly Setting IBM PPR Epson FX ML Utility NLQ Courier NLQ Gothic HSD 10 12 15 17.1 20 cpi No Yes...
Page 153 Page Width * Page Length Gap Control Bottom Feed Line Spacing Form Tear-Off Skip Over Perforation Page Width * Page Length Gap Control Top Feed Line Spacing Form Tear-Off * * * * * * * Bottom Margin Page Width * Page Length Gap Control Wait Time...
Page 154 Paper Out Override Print Registration Operator Panel Function Reset Inhibit Print Suppress Effective Auto LF Auto CR * * * * CSF Bin Select * * * Print DEL Code * * SI Select Pitch (10 CPI) * * SI Select Pitch (12 CPI) * * Time Out Print Auto Select Printhead Gap Adjust...
Page 155 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 updates to this material. (http://bpx.okidata.com)
Page 156: Top Of Form
2. Press and hold the QUIET and FF/LOAD switches while you power on the printer. Note: The factory default Top of Form Setting is 1 inch. 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) Service Guide ML520/521 Chapter 3 Maintenance &...
Page 157: Paper Park
When the printer is set to a different paper path, the printhead will travel back and forth. The pins are "gently" fired to sense paper thickness and set the printhead gap. 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) Service Guide ML520/521 Chapter 3 Maintenance &...
Page 158: Tear Feature
Paper will remain in the tear off position until the printer receives data. Then, the paper is retracted to the initial print position. To activate the Tear Feature, press TEAR. 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) Service Guide ML520/521 Chapter 3 Maintenance &...
Page 159 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.
Page 160 3. The paper will retract to the Top of Form position. 4. Release TEAR. 5. The paper advances to the tear bar position. 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 161: Resets
2. Press and hold the QUIET and FF/LOAD switches while you power on the printer. NOTE: The factory default Top of Form Setting is 1 inch. 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) Service Guide ML520/521 Chapter 3 Maintenance &...
Page 162: Cleaning
Area around carriage shaft Space Rack Platen Covers 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) Service Guide ML520/521 Chapter 3 Maintenance & Disassembly...
Page 163 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 accumulation of paper dust is the most frequent cause of print quality problems in a dot matrix printer.
Page 164 9. Teeth of the gears in the Gear Case Assembly 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 165: Shipping Instructions
3. Make sure the printhead is secured so it will not move during shipment. 4. Pack the unit, using the materials from Step 1. 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) Service Guide ML520/521 Chapter 3 Maintenance &...
Page 166 Okidata, using one of the methods listed. Refer to the Service Center Reference Guide for information on contacting Okidata. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 167: Printer Serial Number Identification
Example Printer Serial Number: 401A0154693 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) Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Date Code 401 (4 = year.
Page 168: Firmware Revision Identification
Okidata. Have this information available during your service call. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 169: Reporting Problems - General Information
Okidata know. Refer to the Service Center Reference Guide for information on contacting Okidata. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 170: Problem Lists
Okidata can provide the best possible information. Your cooperation is greatly appreciated. Thank you for your help! 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 171: Reporting Methods
Description of Problem Document Name (with page number or procedure) with error or problem. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 172: Troubleshooting Updates
The TSBs are distributed through Okilink II. Refer to the Service Center Reference Guide for information on accessing Okilink II. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 173: Troubleshooting Tips
8. Are the printer drivers being used correct for the printer? 9. Is the printer driver being used the latest (current) release? 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 174: Problem Categories
A solid ALARM Lamp usually indicates a cover open, paper jam or paper-end (out of paper) condition. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 175 No Which port is not receiving data? Parallel Refer to RAP 10. Serial Refer to RAP 11. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 176: Tips For Preventing Image Problems
2. Make sure that the paper you are using is within specifications. Section 1 of this Service Handbook. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 177: Common Problems
Refer to the Printer Handbook for emulation/driver selections. The closer the driver is to the top of the list in the Printer Service Guide ML520/521 Chapter 4 Failure & Repair Analysis...
Page 178 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 your software, check to be sure that you have entered them correctly.
Page 179 SHIFT button while pressing SEL/MENU button) and change the I-Prime item (in the Parallel I/F Group) to Invalid. 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 180: Abnormal Output - Output Samples
4. Paper is not within specification. Refer to Section One for paper specification. Uneven Print Density Possible Causes: 1. Printhead gap not within specification. Perform the printhead gap adjustment. Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Page: 125...
Page 181 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.
Page 182 2. Refer to the next section and / or Technical Service Bulletin 3309. 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 183: Left Margin Drifting Problem
6. If the problem continues, check all assemblies and connections. Then, contact Okidata Technical Information for further assistance. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 184: Fault Alarms
6. The Recommended Action will direct you to the actions listed below. Follow a specific RAP. Replace items in a listed order. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 185: Alarm/Led Display Troubleshooting Table Index
Always check that all connectors on the printer are making good contact. NOTE: Reference Numbers 25 and 26 use identical Operator Panel displays ALAR UTILITY Blinkin Blinkin Blinkin Blinkin Blinkin Blinkin Blinkin Blinkin Blinkin Blinkin Blinkin Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Page: 128 MENU Referen Number...
Page 186 Blinkin Blinkin Blinkin Blinkin Blinkin Blinkin Blinkin Blinkin Blinkin Blinkin 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) Blin Blin Blinkin Blinkin...
Page 187 Printhead A/D Alarm Printhead Gap Alarm Printhead Data Transfer Alarm Printhead Type Alarm Printhead Connection Alarm Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Cause Recommended Action Space motor IPT does Refer to RAP 02. not occur in specified time.
Page 188 CAUTION: Always check that all connectors on the printer are making good contact. 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) Self adjust was not Check the printhead successful.
Page 189: Repair Analysis Procedures (Raps)
4. All RAPs begin with a START statement, followed by questions or another type of statement. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 190 Operator Panel Malfunction Parallel Interface Problem Serial Interface Problem 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) Service Guide ML520/521 Chapter 4 Failure & Repair Analysis...
Page 191: Rap 01 No Power Supplied To Printer
Has the problem been resolved? Yes End of procedure. No Go to B. No Replace the following in the order listed below. Check operation before replacing next item in list. Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Page: 132...
Page 192 4. PROM 05CA Has the problem been resolved? Yes End of procedure. No Contact Technical Support. 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 193: Rap 02 No Spacing Operation
Has the problem been resolved? Yes End of procedure. No Replace the ribbon feed mechanism Has the problem been resolved? Yes End of procedure. No Replace the PROM (O5CA) Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Page: 133...
Page 194 Has the problem been resolved? Yes End of procedure. No Contact Technical Support. 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 195: Rap 03 Printhead Homing Error
No Replace the main control board. Has the problem been resolved? Yes End of procedure. No Replace the space motor assembly. Has the problem been resolved? Yes End of procedure. No Contact Technical Support. Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Page: 134...
Page 197: Rap 04 Paper Jam During Paper Loading
Has the problem been resolved? Yes End of procedure. No Contact Technical Support. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 198: Rap 05 Printhead Pins Not Firing
Has the problem been resolved? Yes End of procedure. No Contact Technical Support. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 199: Rap 06 Poor Print Quality
Has the problem been resolved? Yes End of procedure. No Go to C 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 200: Rap 07 Ribbon Feed Problem
Has the problem been resolved? Yes End of procedure. No Contact Technical Support. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 201: Rap 08 Line Feed Problem
Replace the line feed motor assembly. Has the problem been resolved? Yes End of procedure. No Replace the main control board. Has the problem been resolved? Yes End of procedure. No Contact Technical Support. Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Page: 139...
Page 203: Rap 09 Operation Panel Malfunction
Has the problem been resolved? Yes End of procedure. No Contact Technical Support. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 204: Rap 10 Parallel Interface Problem
Replace the interface cable. Has the problem been resolved? Yes End of procedure. No Replace the main control board. Has the problem been resolved? Yes End of procedure. No Contact Technical Support. Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Page: 141...
Page 206: Rap 11 Serial Interface Problem
No Replace the main control board. Has the problem been resolved? Yes End of procedure. No Contact Technical Support. No Replace the power supply unit. Has the problem been resolved? Yes End of procedure. Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Page: 142...
Page 207 No Replace the main control board. Has the problem been resolved? Yes End of procedure. No Contact Technical Support. 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 208: Printer Tests
The Serial Interface Loopback Test checks the operation of the serial interface board. The Hexadecimal Dump Mode checks the data transfer between the computer and printer. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 209 3. Press and hold the QUIET switch while powering on the printer. You must hold the QUIET switch until the test starts to print. 4. The test will continue to print until you press the SEL switch or run out of paper. Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Page: 144...
Page 211 3. Press and hold the LF switch while powering on the printer. You must hold the LF switch until the test starts to print. 4. The one page test will print, then stop. Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Page: 145...
Page 213 Loopback Connector Configuration 1. Jumper the following pins together. Pin 2 to Pin 3 Pin 4 to Pin 5 Pin 8 to Pin 11 Pin 6 to Pin 20 Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Page: 146...
Page 215: Serial Cable Information
Cannon DB-25P plug (or equivalent) with 25 pins Cannon DB-C2-J9 (or equivalent) connector shell 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 216: Serial Interface Signal Requirements
Serial Interface Signal Requirements 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) Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Page: 148...
Page 217: Commonly Used Serial Cable Configurations
IBM 25-Pin Cable Configuration Computer Printer IBM 9-Pin Cable Configuration 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) Service Guide ML520/521 Chapter 4 Failure & Repair Analysis...
Page 218: Hexadecimal Dump Mode
8. Send data to the printer from the computer. 9. To exit Hexadecimal Dump Mode, power OFF the printer. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 219: Resistance Checks
The printhead coil resistance values ARE NOT LISTED. The individual printwire control lines CANNOT be accessed on this printhead. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 220: Layout Diagram
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) Service Guide ML520/521 Chapter 4 Failure & Repair Analysis Page: 152...
Page 221: Printhead
The printhead coil resistance values ARE NOT LISTED. The individual printwire control lines CANNOT be accessed on this printhead. 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) Service Guide ML520/521 Chapter 4 Failure &...
Page 222: Line Feed Motor Resistance
4.9.03 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 this material. (http://bpx.okidata.com) Service Guide ML520/521 Chapter 4 Failure &...
Page 223: Space Motor Resistance
4.9.04 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 material. (http://bpx.okidata.com) Service Guide ML520/521 Chapter 4 Failure &...
Page 224 Test Points Where an item is not applicable, the word NONE will be listed. 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) Service Guide ML520/521...
Page 225: A.2 Index To Charts
Power Supply Assembly Space Motor Board RS232-C Serial Interface Board 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) Service Guide ML520/521 Chapter A Reference Charts...
Page 226: Board Layout
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: A.2.01 Main Controller Board (Fjim)
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 regulated on the main controller board.
Page 229: A.2.02 Operator Panel Board (Leop)
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 alarms and printer status.
Page 231: A.2.03 Power Supply Assembly
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.
Page 233: A.2.04 Space Motor Board
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 microprocessor.
Page 235: A.2.05 Rs232-C Serial Interface Board - Option (Lxhi)
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...
Page 237: B Illustrated Parts Listing B.1 Overview - B.1.01 General Information
Locate the part and its part number in this section. Appendix B is cross-referenced to Section Three (Maintenance). 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 238: Format
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 procedure. Items with the comments RSPL (Recommended Spare Parts List), Consumable, Document, or Option are available from Okidata.
Page 239: Current Part Numbers
II, Faxable Facts, and Technical Information. Refer to the Service Center Reference Guide for information on accessing these resources. 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 240: B.1.02 Definition Of Terms
Page: 167 Service Guide ML520/521 Chapter B Illustrated Parts Listing B.1.02 Definition of Terms Assemblies Assemblies are parts grouped under a single description and/or part number. Generally, individual items in an assembly are not available from Okidata. Assemblies are surrounded by broken line boxes in the diagrams.
Page 241 This part is specific to the Microline 521 printer. Both This part is used by both the Microline 520 and Microline 521 printers. 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 242: B.1.03 Parts Ordering Information
Use this Appendix, Okilink II, Faxable Facts, or contact Okidata Technical Support to find the correct part number. Refer to the Service Center Reference Guide for information on contacting Okidata. 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 243: B.2 Charts
Documentation B.2.13 Service Training Kit Revision List 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) Service Guide ML520/521 Chapter B Illustrated Parts Listing...
Page 244: Overview
Page: 170 Service Guide ML520/521 Chapter B Illustrated Parts Listing Overview 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 245: B.2.01 Printer
62410002 N/A Printer: ML521 Parallel (Epson/IBM/ML Comp.) 220 V 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) Service Guide ML520/521 Chapter B Illustrated Parts Listing...
Page 246: B.2.02 Upper Cover Assembly
B.2.02 Upper Cover Assembly Item Okidata P/N Oki-J 53066902 1PP4094-6501P2 53067002 1PP4094-7201P2 51009401 N/A 51009501 N/A 53067101 2PA4094-7381G1 Service Guide ML520/521 Chapter B Illustrated Parts Listing Description Comments Refer to B.1.02 Cover: Upper RSPL 520 (Narrow) Cover: Upper RSPL 521 (Wide)
Page 247 53067201 2PA4094-7382G1 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) Cover: Access RSPL 521 (Wide) 3.2.06...
Page 248: B.2.03 Printer General Assembly
B.2.03 Printer General Assembly Item Okidata P/N Oki-J 53562601 2PP4094-6507P3 53067301 2PP4094-6506P1 55072401 4YA4042-1515G301 56301702 540A2036M1202 Service Guide ML520/521 Chapter B Illustrated Parts Listing Description Comments Refer to B.1.02 Knob: Platen RSPL Both (ML500 Series) Cover: (B) for RSPL Both Card Slot...
Page 249 50707501 4PP4025-3621P1 56306201 540A2062T2102 56306101 540A2067T1252 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) PCB: LEOP RSPL Both (Operator. Panel) Panel: Operator RSPL Both...
Page 250: B.2.04 Printer Unit
Okidata P/N Oki-J 53563101 3PA4025-3720G1 53563201 3PA4025-3721G1 50804601 3PP4025-3315P1 50804701 3PP4025-3322P1 50804801 3PP4025-3321P1 50804902 4PP4025-3323P2 Service Guide ML520/521 Chapter B Illustrated Parts Listing Description Comments Refer to B.1.02 Frame: Main RSPL 520 (Narrow) Frame: Main RSPL 521 (Wide) Lever: Bottom RSPL Both...
Page 251 53563502 4PP4025-3381P2 53067601 4PA4025-3382G1 50923601 4PB4025-3385P1 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) Cord: Connection RSPL Both Line Feed Motor: Line Feed...
Page 252: B.2.05 Printer Unit
Item Okidata P/N Oki-J 53563101 3PA4025-3720G1 53563201 3PA4025-3721G1 51228001 4PP4025-3340P1 51228101 3PP4025-3341P1 50805301 3PP4025-3352P1 Service Guide ML520/521 Chapter B Illustrated Parts Listing Description Comments Refer to B.1.02 Frame: Main RSPL 520 (Narrow) Frame: Main RSPL 521 (Wide) Gear: Change RSPL Both...
Page 253 3PA4025-3370G1 50098302 N/A 53341501 3PA4025-3440G2 53341601 3PA4025-3530G2 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) Gear: Idle RSPL Both Lever: Change RSPL Both...
Page 254: B.2.06 Printer Unit
B.2.06 Printer Unit Item Okidata P/N Oki-J 53563101 3PA4025-3720G1 53563201 3PA4025-3721G1 50922901 4PP4025-3316P1 50922801 4PP4025-3324P1 Service Guide ML520/521 Chapter B Illustrated Parts Listing Description Comments Refer to B.1.02 Frame: Main RSPL 520 (Narrow) Frame: Main RSPL 521 (Wide) Spring: Front...
Page 255 53341101 4PP4025-3317P1 53341202 4PP4025-3327G1 51227801 3PP4025-3318P1 51227901 3PP4025-3505P1 50097301 N/A 50097401 1PP4025-3506P2 50923301 3PP4025-3346G1 50923401 3PP4025-3511G1 50805201 4PP4025-3351P1 51228301 4PP4025-3350P1 50924701 4PP4025-3386P1 50097701 3PA4025-3360G2 50097801 3PA4025-3515G2 53341301 3PB4025-3364P1 53341401 3PB4025-3517P1 50097501 3PA4025-3330G1 50097502 3PA4025-3330G2 Holder: Front RSPL Both Roller Roller: Front RSPL Both Pressure Shaft: Front...
Page 257: B.2.07 Carriage Assembly
B.2.07 Carriage Assembly Item Okidata P/N Oki-J 50707401 3PP4025-3431P1 53562801 3PP4025-3430P1 51228501 3PA4025-3406G1 Service Guide ML520/521 Chapter B Illustrated Parts Listing Description Comments Refer to B.1.02 Clamp: Head RSPL Both Protector: Ribbon RSPL Both Gear: Case RSPL Both (Assembly) Page: 177...
Page 258 3PP4025-3393P1 N/A N/A 50925001 3PP4025-3397P1 50098901 4PP4025-3394G1 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) Connector: PC RSPL Both HD40 Holder: RSPL Both...
Page 259: B.2.08 Options
B.2.08 Options Item Okidata P/N Oki-J 70022501 N/A 70022701 N/A 70023001 N/A 70023201 N/A 70022901 N/A Service Guide ML520/521 Chapter B Illustrated Parts Listing Description Comments Refer to B.1.02 Kit: Single Bin Option 520 CSF 5000 Narrow Kit: Single Bin...
Page 260 4YB4021-1144P1 55073302 4YB4021-1144P2 56306201 540A2062T2102 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) Kit: Push Tractor Option 521 (Bottom) Wide Kit: Roll Paper...
Page 261: B.2.09 Option Parts
2PA4094-6510G4 50098701 4PP4094-7385G1 50098801 4PP4094-7386G1 51010001 1PP4053-2570P1 51010101 1PP4053-2571P2 53067401 1PP4053-2574P1 Service Guide ML520/521 Chapter B Illustrated Parts Listing Description Comments Refer to B.1.02 Tractor: Pull and Option RSPL Both Bottom Assembly (Right) Tractor: Pull and Option RSPL Both Bottom Assembly...
Page 262 50062802 4PB4053-1705G2 53321501 3PB4025-1941P1 53448501 4PB4025-1914P1 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) Cover: Side Option RSPL Both (Right) Cut-Sheet Feeder Supporter: Front...
Page 263: B.2.10 Consumables
Service Guide ML520/521 Chapter B Illustrated Parts Listing B.2.10 Consumables 52107001 N/A Ribbon: Black Consumable Both 3.2.02 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 264: B.2.11 Packing Materials
53565101 N/A 53565201 N/A 53565401 N/A 53565402 N/A 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) Service Guide ML520/521 Chapter B Illustrated Parts Listing...
Page 265: B.2.12 Documentation
52050809 N/A 58059501 N/A 59256801 N/A 58232502 N/A 52033001 N/A 53436029 N/A 52050809 N/A 58059501 N/A 58306101 N/A Service Guide ML520/521 Chapter B Illustrated Parts Listing Description Comments Refer to B.1.02 Kit: ML520/521 Document Both Service Training Kit: ML520/521 Document Both...
Page 266 * * Obtain this form by faxing a request to Okidata Marketing Communications. Refer to the Service Center Reference Guide for information on contacting Okidata. 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 267: B.2.13 Service Training Kit Revision List
58090901 N/A 12 A 59257801 N/A 13 A 59257901 N/A 14 A 59256801 N/A 15 A 57519801 N/A Service Guide ML520/521 Chapter B Illustrated Parts Listing Description Comments Refer to B.1.02 Kit: ML520/521 Document Both Service Training Label: Box Document...
Page 268 P/N 58229402 Microline 520/521 Service Training Kit This kit was replaced by P/N 58229403. Items in the training kit (except for the Printer Handbook) are NOT available separately. Item Okidata P/N Oki-J 58229402 N/A 52063205 N/A 58090402 N/A 59257802 N/A...
Page 269 58306101 N/A 57519802 N/A 52063204 Rev B N/A 53570401 N/A 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) Description Comments Refer to B.1.02...

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Oki ML520 Service Manual

About this Manual

1 Product Specifications

2 Principles of Operation

3 Maintenance & Disassembly

4 Failure & Repair Analysis

A Reference Charts

Quick Links

Troubleshooting

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Summary of Contents for Oki ML520