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Phaser Color Laser Printer
®
7750
Service
Manual
Phaser 7750 Color Laser Printer
Service Manual
Warning The following servicing instructions are for use by qualified service personnel only. To avoid personal injury, do not perform any servicing other than that contained in the operating instructions, unless you are qualified to do so. First Printing: December 2003 071-0864-00
Copyright © 2004, Xerox Corporation. All Rights Reserved. Unpublished rights reserved under the copyright laws of the United States. Contents of this publication may not be reproduced in any form without permission of Xerox Corporation. Copyright protection claimed includes all forms of matters of copyrightable materials and information now allowed by statutory or judicial law or hereinafter granted, including without limitation, material generated from the software programs which are displayed on the screen such as styles, templates, icons, screen displays, looks, etc. XEROX®, The Document Company®, the stylized X®, CentreWare®, infoSMART®, Made For Each Other®, Phaser®, PhaserSMART®, and the TekColor® icon are registered trademarks of Xerox Corporation. PhaserCalTM, PhaserMatchTM, PhaserPortTM, PhaserToolsTM, and the TekColorTM name are trademarks of Xerox Corporation. Adobe® Reader®, Illustrator®, PageMaker®, Photoshop®, PostScript®, ATM®, Adobe Garamond®, Birch®, Carta®, Mythos®, Quake®, and Tekton® are registered trademarks and Adobe JensonTM, Adobe Brilliant ScreensTM technology, and IntelliSelectTM are trademarks of Adobe Systems Incorporated or its subsidiaries which may be registered in certain jurisdictions. Apple®, LaserWriter®, LocalTalk®, Macintosh®, Mac® OS, AppleTalk®, TrueType2®, Apple Chancery®, Chicago®, Geneva®, Monaco®, and New York® are registered trademarks, and QuickDrawTM is a trademark of Apple Computer Incorporated. PCL® and HP-GL® are registered trademarks of Hewlett-Packard Corporation. Windows® and Windows NT® are registered trademarks of Microsoft Corporation. Novell®, NetWare®, NDPS®, NDS®, and Novell Directory Services® are registered trademarks, and IPXTM and Novell Distributed Print ServicesTM are trademarks of Novell, Incorporated. Sun® and Sun Microsystems® are registered trademarks of Sun Microsystems, Incorporated. SPARC® is a registered trademark of SPARC International, Incorporated. SPARCstationTM is a trademark of SPARC International, Incorporated, licensed exclusively to Sun Microsystems, Incorporated. SWOP® is a registered trademark of SWOP, Inc. UNIX® is a registered trademark in the US and other countries, licensed exclusively through X/Open Company Limited. As an ENERGY STAR® partner, Xerox Corporation has determined that this product meets the ENERGY STAR guidelines for energy efficiency. The ENERGY STAR name and logo are registered U.S. marks.
This product uses code for SHA-1 written by John Halleck, which is being used with his permission. This product includes an implementation of LZW licensed under U.S. Patent 4,558,302. Other marks are trademarks or registered trademarks of the companies with which they are associated. PANTONE® Colors generated may not match PANTONE-identified standards. Consult current PANTONE Publications for accurate color. PANTONE® and other Pantone, Inc. trademarks are the property of Pantone, Inc. © Pantone, Inc., 2000.
Service Terms
Manual Terms
Various terms are used throughout this manual to either provide additional information on a specific topic or to warn of possible danger present during a procedure or action. Be aware of all symbols and terms when they are used, and always read NOTE, CAUTION, and WARNING statements. Note A note indicates an operating or maintenance procedure, practice or condition that is necessary to efficiently accomplish a task. A note can provide additional information related to a specific subject or add a comment on the results achieved through a previous action. Caution A caution statement indicates an operating or maintenance procedure, practice or condition that, if not strictly observed, results in damage to, or destruction of, equipment. Warning A warning statement indicates an operating or maintenance procedure, practice or condition that, if not strictly observed, results in injury or loss of life.
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Symbols Marked on the Product
DANGER high voltage.
Protective ground (earth) symbol.
Hot surface on or in the printer. Use caution to avoid personal injury.
0
The surface is hot while the printer is running. After turning off the power, wait 30 minutes.
30 min.
Avoid pinching fingers in the printer. Use caution to avoid personal injury.
Use caution (or draws attention to a particular component). Refer to the manual(s) for information.
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Phaser 7750 Color Laser Printer
Power Safety Precautions
Power Source
For 110 VAC printers, do not apply more than 140 volts RMS between the supply conductors or between either supply conductor and ground. Use only the specified power cord and connector. For 220 VAC printers, do not apply more than 264 volts RMS between the supply conductors or between either supply conductor and ground. Use only the specified power cord. This manual assumes that the reader is a qualified service technician. Plug the three-wire power cord (with grounding prong) into a grounded AC outlet only. If necessary, contact a licensed electrician to install a properly grounded outlet. If the product loses its ground connection, contact with conductive parts may cause an electrical shock.
Disconnecting Power
Turning the power off using the On/Off switch does not completely de-energize the printer. You must also disconnect the printer power cord from the AC outlet. Position the power cord so that it is easily accessible during servicing so that you may power down the printer during an emergency. Disconnect the power plug by pulling the plug, not the cord. Disconnect the power cord in the following cases:
if the power cord or plug is frayed or otherwise damaged, if any liquid or foreign material is spilled into the case, if the printer is exposed to any excess moisture, if the printer is dropped or damaged, if you suspect that the product needs servicing or repair, whenever you clean the product.
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Electrostatic Discharge (ESD) Precautions
Some semiconductor components, and the respective sub-assemblies that contain them, are vulnerable to damage by Electrostatic discharge (ESD). These components include Integrated Circuits (ICs), Large-Scale Integrated circuits (LSIs), field-effect transistors and other semiconductor chip components. The following techniques will reduce the occurrence of component damage caused by static electricity. Be sure the power is off to the chassis or circuit board, and observe all other safety precautions.
Immediately before handling any semiconductor components assemblies, drain the electrostatic charge from your body. This can be accomplished by touching an earth ground source or by wearing a wrist strap device connected to an earth ground source. Wearing a wrist strap will also prevent accumulation of additional bodily static charges. Be sure to remove the wrist strap before applying power to the unit under test to avoid potential shock. After removing a static sensitive assembly from its anti-static bag, place it on a grounded conductive surface. If the anti-static bag is conductive, you may ground the bag and use it as a conductive surface. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage some devices. Do not remove a replacement component or electrical sub-assembly from its protective package until you are ready to install it. Immediately before removing the protective material from the leads of a replacement device, touch the protective material to the chassis or circuit assembly into which the device will be installed. Minimize body motions when handling unpackaged replacement devices. Motion such as your clothes brushing together, or lifting a foot from a carpeted floor can generate enough static electricity to damage an electro-statically sensitive device. Handle IC's and EEPROM's carefully to avoid bending pins. Pay attention to the direction of parts when mounting or inserting them on Printed Circuit Boards (PCB's).
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Phaser 7750 Color Laser Printer
Service Safety Summary
General Guidelines
For qualified service personnel only: Refer also to the preceding Power Safety Precautions. Avoid servicing alone: Do not perform internal service or adjustment of this product unless another person capable of rendering first aid or resuscitation is present. Use care when servicing with power: Dangerous voltages may exist at several points in this product. To avoid personal injury, do not touch exposed connections and components while power is on. Disconnect power before removing the power supply shield or replacing components. Do not wear jewelry: Remove jewelry prior to servicing. Rings, necklaces and other metallic objects could come into contact with dangerous voltages and currents. Power source: This product is intended to operate from a power source that will not apply more then 264 volts RMS for a 220 volt AC outlet or 140 volts RMS for a 110 volt AC outlet between the supply conductors or between either supply conductor and ground. A protective ground connection by way of the grounding conductor in the power cord is essential for safe operation.
Warning Labels
Read and obey all posted warning labels. Throughout the printer, warning labels are displayed on potentially dangerous components. As you service the printer, check to make certain that all warning labels remain in place.
Safety Interlocks
Make sure all covers and the printer's front panel are in place and all interlock switches are functioning correctly after you have completed a printer service call. If you bypass an interlock switch during a service call, use extreme caution when working on or around the printer.
CLASS 1 LASER PRODUCT
The Phaser 7750 Color Laser Printer is certified to comply with Laser Product Performance Standards set by the U.S. Department of Health and Human Services as a Class 1 Laser Product. This means that this is a class of laser product that does not emit hazardous laser radiation; this is possible only because the laser beam is totally enclosed during all modes of customer operation. When servicing the printer or laser unit, follow the procedures specified in this manual and there will be no hazards from the laser.
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Servicing Electrical Components
Before starting any service procedure, switch off the printer power and unplug the power cord from the wall outlet. If you must service the printer with power applied, be aware of the potential for electrical shock. Warning Turning the power off by using the On/Off switch does not completely deenergize the printer. You must also disconnect the printer power cord from the AC outlet. Position the power cord so that it is easily accessible during servicing. Warning Do not touch any electrical component unless you are instructed to do so by a service procedure.
7500-117
Servicing Mechanical Components
When servicing mechanical components within the printer, manually rotate drive assemblies, rollers, and gears. Warning Do not try to manually rotate or manually stop the drive assemblies while any printer motor is running.
7500-118
Servicing Fuser Components
Warning This printer uses heat to fuse the toner image to media. The Fuser Assembly is VERY HOT. Turn the printer power off and wait at least 5 minutes for the Fuser to cool before you attempt to service the Fuser Assembly or adjacent components.
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Phaser 7750 Color Laser Printer
Regulatory Specifications
United States
The equipment described in this manual generates and uses radio frequency energy. If it is not installed properly in strict accordance with Xerox' instructions, it may cause interference with radio and television reception or may not function properly due to interference from another device. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:
Reorient or relocate the receiver (device being interfered with). Increase the separation between the printer and the receiver. Connect the printer into an outlet on a circuit different from that which the receiver is connected. Route the interface cables on the printer away from the receiver. Consult the dealer, Xerox service, or an experienced radio/television technician for help.
Changes or modifications not expressly approved by Xerox can affect the emission and immunity compliance and could void the user's authority to operate this product. To ensure compliance, use shielded interface cables. A shielded parallel cable can be purchased directly from Xerox at www.xerox.com/office/supplies. Xerox has tested this product to internationally accepted electromagnetic emission and immunity standards. These standards are designed to mitigate interference caused or received by this product in a normal office environment. This product is also suitable for use in a residential environment based on the levels tested. In the United States this product complies with the requirements of an unintentional radiator in part 15 of the FCC rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference; (2) this device must accept any interference received, including interference that may cause undesired operation.
Canada
This digital apparatus does not exceed the Class B limits for radio noise emissions from digital apparatus set out in the Radio Interference Regulations of the Canadian Department of Communications, ICES-003. Le présent appareil numérique n'émet pas de bruits radioélectrique dépassant les limits applicables aux appareils numériques de la classe B prescrites dans le Réglement sur le brouillage radioélectrique édicté par le ministere des Communications du Canada, NMB-003.
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European Union
Xerox Corporation declares, under our sole responsibility, that the printer to which this declaration relates is in conformity with the following standards and other normative documents: Following the provisions of the Low Voltage Directive 73/23/EEC and its amendments:
EN 60950 (IEC 60950) "Safety of Information Technology Equipment including Electrical Business Equipment"
Following the provisions of the Electromagnetic Compatibility Directive 89/336/EEC and its amendments:
EN 55022:1998 (CISPR 22) EN 61000-3-2:1995 +A1:1998+A2:1998 (IEC61000-3-2) EN 61000-3-3:1995 (IEC61000-3-3) EN 55024:1998 (CISPR 24) "Limits and Methods of measurement of radio interference characteristics of Information Technology Equipment." Class B. "Part 3: Limits - Section 2: Limits for harmonic current emissions (equipment input current less than or equal to 16A per phase)." "Part 3: Limits - Section 3: Limitation of voltage fluctuations and flicker in low-voltage supply systems for equipment with rated current less than or equal to 16A." "Information technology equipment - Immunity characteristics Limits and methods of measurement. "
CISPR 24 Immunity Phenomena
Electrostatic Discharge Radio-Frequency Electromagnetic Field (radiated) Fast Burst Transients
Basic Standard
IEC 61000-4-2:1995 IEC 61000-4-3:1995
Test Specification
6 kV Contact, 10 kV Air 80-1000 MHz, 3 V/m, 80% AM @ 1 KHz 5/50 Tr/Th ns, 5 kHz Rep. Freq 0.5 kV Signal Lines 1 kV AC Mains Combination wave 2.0 kV Common mode 2.0 kV Differential mode 0.15 - 80 MHz, 3 V, 80% AM @ 1 kHz >95% dip for ½ cycle @ 50 Hz 30% dip for 25 cycles @ 50 Hz
IEC 61000-4-4:1995
Line Surge
IEC 61000-4-5:1995
Radio-Frequency Electromagnetic Field (Conducted) Line voltage dips
IEC 61000-4-6:1996
IEC 61000-4-11:1994
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Phaser 7750 Color Laser Printer
CISPR 24 Immunity Phenomena Line voltage drop-out
Basic Standard IEC 61000-411:1994
Test Specification >95% dropout for 250 cycles @ 50 Hz
This product, if used properly in accordance with the user's instructions, is neither dangerous for the consumer nor for the environment. A signed copy of the Declaration of Conformity for this product can be obtained from Xerox.
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Phaser 7750 Color Laser Printer
Contents
Service Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iii Symbols Marked on the Product . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iv Power Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Electrostatic Discharge (ESD) Precautions . . . . . . . . . . . . . . . . . . . . . . . . .vi Service Safety Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Regulatory Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ix
1 General Information
Printer Introduction and Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 Phaser 7750 Printer Configurations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 Parts of the Printer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 Exterior - Front View. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 Exterior - Rear View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5 Phaser 7750 Front Panel Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 Image Processor Board and Rear Panel Host Interface . . . . . . . . . . . . . . 1-7 Routine Maintenance Items and Consumables . . . . . . . . . . . . . . . . . . . . 1-8 Printer Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9 Physical Dimensions and Clearances . . . . . . . . . . . . . . . . . . . . . . 1-9 Mounting Surface Specification . . . . . . . . . . . . . . . . . . . . . . . . . 1-10 Functional Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12 Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13 Media and Tray Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
2 Theory of Operation
Summary of the Phaser 7750 Print Process . . . . . . . . . . . . . . . . . . . . . . 2-2 Paper Path of the Printer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4 Paper Size Sensing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5 Paper Feeding and Sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5 Fuser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8 EAHG Toner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9 Technology Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10 Standby Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10 Machine Run Control and NVRAM . . . . . . . . . . . . . . . . . . . . . . . 2-10 Drive Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11 System Power Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13 ROS and Regicon Technology Overview . . . . . . . . . . . . . . . . . . . . . . . . 2-15 Write Black Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15 RegiCon Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17 #1 Skew (Fine) Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19 #2 IN/OUT Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19 #3 Center Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19
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#4 Skew (Rough) Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . View the RegiCon Patterns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ATC Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ADC Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ADC Output Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lower Tray Feeders Sensor and Board Locations . . . . . . . . . . .
2-19 2-20 2-22 2-24 2-25 2-26 2-28
3 Error Messages and Codes
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2 Accessing the Printer's Error History . . . . . . . . . . . . . . . . . . . . . . 3-2 Service Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 Service RIP (Every Call) Procedures . . . . . . . . . . . . . . . . . . . . . . 3-4 Overview for Troubleshooting Error Codes . . . . . . . . . . . . . . . . . . . . . . . 3-5 Using the Troubleshooting Procedures . . . . . . . . . . . . . . . . . . . . 3-5 System Startup and POST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7 Power On Self Test (POST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7 POST Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8 Error Messages and Codes Index Table. . . . . . . . . . . . . . . . . . . . . . . . . 3-10 Error Messages and Codes Procedures. . . . . . . . . . . . . . . . . . . . . . . . . 3-12 Black ATC Sensor Failure, Code 15 . . . . . . . . . . . . . . . . . . . . . . 3-15 Transfer Roller Contact Failure, Code 20 Transfer Roller Retract Failure, Code 21. . . . . . . . . . . . . . . . 3-17 1st BTR Contact or Retract Failure. . . . . . . . . . . . . . . . . . . . . . . 3-18 Accumulator Belt Home Position Took Too Long, Code 30 Accumulator Belt Home Position Failure, Code 31 . . . . . . . . 3-19 Accumulator Belt Edge Sensor Failure, Code 32 Accumulator Belt Drive Logic Failure, Code 34 . . . . . . . . . . 3-22 Unexpected Accumulator Belt Home Sensor Signal, Code 33 . . 3-24 Fuser Main Lamp Failure, Code 35. . . . . . . . . . . . . . . . . . . . . . . 3-25 Install or Reseat Fuser, Code 41 . . . . . . . . . . . . . . . . . . . . . . . . 3-26 Fuser STS (Front) Warm Time Failure, Code 42. . . . . . . . . . . . . 3-27 Fuser SSR1 On Time Failure, Code 43 . . . . . . . . . . . . . . . . . . . . 3-27 Fuser Sub Lamp Overheat Failure, Code 44 . . . . . . . . . . . . . . . . 3-29 Fuser STS (Rear) Failure, Code 45 . . . . . . . . . . . . . . . . . . . . . . . 3-30 Fuser STS (Rear) Warm Time Failure, Code 46 . . . . . . . . . . . . . 3-31 Fuser SSR2 On Time Failure, Code 47 . . . . . . . . . . . . . . . . . . . . 3-31 Fan Failure, Code 48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33 Imaging Unit Motor Failure, Code 60 . . . . . . . . . . . . . . . . . . . . . 3-35 Imaging Unit [1] [2] [3] [4] Communications Failure, Code 70, 71, 72, 73 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36 Black Imaging Unit Motor Failure. . . . . . . . . . . . . . . . . . . . . . . . 3-37 Waste Cartridge Full Detection Sensor Failure, Code 78 . . . . . . 3-38 Engine Logic Board Failure, Code 80 . . . . . . . . . . . . . . . . . . . . . 3-39 Controller to Engine Communications Failure, Code 81 . . . . . . . 3-39 Engine Logic Board RAM/ROM Failure, Code 82 . . . . . . . . . . . . 3-39
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Phaser 7750 Printer
Engine Logic Board NVRAM Failure, Code 83 . . . . . . . . . . . . . . Controller to Engine Logic Board Time Failure, Code 84 . . . . . . Engine Logic Board Micro Pitch Failure, Code 85. . . . . . . . . . . . High-Voltage Power Supply Failure, Code 86 . . . . . . . . . . . . . . . Tray Lift Failure, Code 87 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tray 1/MPT Size Sensor (7-274), Code? . . . . . . . . . . . . . . . . . . Lower Tray Communication Failure, Code 88. . . . . . . . . . . . . . . Reflective Sensor Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . Transmissive Sensor Procedure. . . . . . . . . . . . . . . . . . . . . . . . . Finisher Stapler Move Sensor On Failure, Code 111 Finisher Stapler Move Sensor Off Failure, Code 112. . . . . . . Finisher Stapler Failure, Code 113 . . . . . . . . . . . . . . . . . . . . . . . Front Tamper Home Sensor Failure, Code 114. . . . . . . . . . . . . . Rear Tamper Home Sensor Failure, Code 115 . . . . . . . . . . . . . . Finisher Stacker Height Sensor Off Failure, Code 116 . . . . . . . . Finisher Stacker Tray Failure, Code 117 . . . . . . . . . . . . . . . . . . . Finisher Stapler Front Corner On Failure, Code 118 Finisher Stapler Front Corner Off Failure, Code 119 . . . . . . . Finisher Eject Clamp Home Sensor On Failure, Code 120 Finisher Eject Clamp Home Sensor Off Failure, Code 121. . . Finisher Decurler Failure, Code 122 . . . . . . . . . . . . . . . . . . . . . . Finisher Set Clamp Failure, Code 123. . . . . . . . . . . . . . . . . . . . . Finisher Communication Failure, Code 124 . . . . . . . . . . . . . . . . Finisher Staple Mode Logic Failure, Code 125 . . . . . . . . . . . . . .
3-40 3-40 3-40 3-40 3-41 3-43 3-44 3-45 3-46 3-47 3-49 3-51 3-52 3-53 3-55 3-57 3-58 3-59 3-60 3-61 3-61
4 General Troubleshooting
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 Service Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 Service Diagnostic Front Panel Button Descriptions. . . . . . . . . . . 4-3 Service Diagnostic Tests Table. . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3 Front Panel Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14 The Printer Does Not Come to a "Ready" State . . . . . . . . . . . . . 4-14 Inoperable Printer Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15 Troubleshooting Power Supplies and Interlocks . . . . . . . . . . . . . . . . . . 4-16 Troubleshooting AC Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16 Troubleshooting the Low-Voltage Power Supplies. . . . . . . . . . . 4-17 Troubleshooting the +3.3 VDC and (2) +5 VDC Low-Voltage Power Supplies . . . . . . . . . . . . . . . 4-18 Troubleshooting the 24 VDC LVPS. . . . . . . . . . . . . . . . . . . . . . . 4-18 Interlock Circuit Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19 Media Jams and the Paper Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21 Media-Based Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21 Operating System and Application Problems. . . . . . . . . . . . . . . . . . . . . 4-23 Windows 2000, Windows XP, Windows Server 2003 Troubleshooting (TCP/IP). . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23 Windows NT 4.x Troubleshooting (TCP/IP) . . . . . . . . . . . . . . . . 4-24
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Windows 98 and Windows Me Troubleshooting . . . . . . . . . . . . 4-25 Macintosh Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-27 Novell NetWare Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . 4-28
5 Print-Quality Troubleshooting
Print-Quality Problems Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2 Defects Associated with Specific Printer Components. . . . . . . . . 5-2 Front Panel Test Prints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4 Troubleshooting Print-Quality Page . . . . . . . . . . . . . . . . . . . . . . . 5-4 Color Test Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5 Analyzing the Test Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6 Solid Fill Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7 Repeating Defects Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8 Remove Print Smears . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8 Engine Test Prints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9 Paper Path Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9 Print Laser Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9 Print Halftones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10 Print Grid 1-Dot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10 Print Fast Scan 8 Tone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11 Initial Actions Before troubleshooting any Print-Quality Problems: . . . . 5-12
6 Adjustments and Calibrations
Registration Control (RegiCon) Adjustment Overview . . . . . . . . . . . . . . . 6-2 Coarse and Fine Skew Adjustments . . . . . . . . . . . . . . . . . . . . . . . 6-3 In/Out Skew Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3 Center Skew Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4 RegiCon Adjustment Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5 RegiCon #1 Fine Skew Adjustment . . . . . . . . . . . . . . . . . . . . . . . 6-7 RegiCon #2 In/Out Skew Adjustment . . . . . . . . . . . . . . . . . . . . . . 6-8 RegiCon #3 Center Skew Adjustment . . . . . . . . . . . . . . . . . . . . . 6-9 RegiCon #4 Coarse Skew Adjustment . . . . . . . . . . . . . . . . . . . . 6-10 Coarse RegiCon Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12 ATC Sensor Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-14 Additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15 Resetting NVRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-16 PostScript NVRAM Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-16 Service Diagnostics NVRAM Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-19 PostScript NVRAM Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-19 Clear Tech Rep Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-20
7 Cleaning and Maintenance
Service Preventive Maintenance Procedure. . . . . . . . . . . . . . . . . . . . . . . 7-2 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
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Phaser 7750 Printer
8 Service Parts Disassembly
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2 Standard Orientation of the Printer for Disassembly . . . . . . . . . . 8-2 General Notes on Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3 Print Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4 Optional Lower Trays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-57
9 Service Parts Lists
Serial Number Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2 Using the Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3 Parts List 1.1 Drive Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4 Part List 1.2 Main Drive Motor Assembly. . . . . . . . . . . . . . . . . . . 9-6 Part List 1.3 Steering Motor and MOB . . . . . . . . . . . . . . . . . . . . . 9-7 Part List 2.1 Tray 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-8 Part List 2.3 Tray Feeder and Left Lower Cover Assy . . . . . . . . . . 9-9 Part List 2.4 Tray 2 Feeder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-10 Part List 2.6 Registration Transport . . . . . . . . . . . . . . . . . . . . . . 9-11 Part List 2.7 Left Cover Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-12 Part List 2.8 Left Cover Assembly: 1 of 2 . . . . . . . . . . . . . . . . . . 9-13 Part List 2.9 Left Cover Assembly: 2of 2 . . . . . . . . . . . . . . . . . . 9-14 Part List 2.10 Exit Transport Assembly . . . . . . . . . . . . . . . . . . . 9-15 Part List 2.12 Tray 1: 1 of 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-16 Part List 2.13 Tray 1: 2 of 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-17 Part List 2.14 Tray 1 Feed Assembly . . . . . . . . . . . . . . . . . . . . . 9-18 Part List 3.1 Laser (ROS) Assembly. . . . . . . . . . . . . . . . . . . . . . 9-19 Part List 4.1 Xerographic Module: 1 of 2 . . . . . . . . . . . . . . . . . . 9-20 Part List 4.2 Xerographic Module: 2 of 2 . . . . . . . . . . . . . . . . . . 9-21 Part List 5.1 Lift Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-22 Part List 5.2 Accumulator Belt Assembly . . . . . . . . . . . . . . . . . . 9-24 Part List 5.6 Accumulator Belt Elevator . . . . . . . . . . . . . . . . . . . 9-25 Part List 6.1 Developer Unit: 1 of 2 . . . . . . . . . . . . . . . . . . . . . . 9-26 Part List 6.2 Developer Unit: 2 of 2 . . . . . . . . . . . . . . . . . . . . . . 9-28 Part List 7.1 Fuser Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-29 Part List 8.1 Air System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-30 Part List 9.1 Electrical Components: 1 of 3 . . . . . . . . . . . . . . . . 9-32 Part List 9.2 Electrical Components: 2 of 3 . . . . . . . . . . . . . . . . 9-34 Part List 9.3 Electrical Components: 3 of 3 . . . . . . . . . . . . . . . . 9-35 Part List 10.1 Front Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-36 Part List 10.2 Top Cover and Front Panel. . . . . . . . . . . . . . . . . . 9-37 Part List 10.3 Rear Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-38 Part List 11.1 Inverter Transport . . . . . . . . . . . . . . . . . . . . . . . . 9-39 Part List 12.1 Duplex Unit Assembly . . . . . . . . . . . . . . . . . . . . . 9-40 Part List 13.1 Image Processor and Engine Control Boards . . . 9-41 Part List 16.1 Lower Trays 3/4/5 Assembly . . . . . . . . . . . . . . . . 9-42 Part List 16.5 Lower Trays Paper Feeder: 1 of 2 . . . . . . . . . . . . 9-43 Part List 16.6 Lower Trays Paper Feeder: 2 of 2 . . . . . . . . . . . . 9-44
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Part List 16.13 Left Cover Assembly (LTD) . . . . . . . . . . . . . . . . Part List 16.14 Tray 4/5 Lift Gear Assembly . . . . . . . . . . . . . . . Part List 16.15 Electrical Components and Caster . . . . . . . . . . . Part List 16.16 Lower Tray Deck . . . . . . . . . . . . . . . . . . . . . . . . Hardware Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9-45 9-46 9-47 9-48 9-49
10 Wiring Diagrams
Plug/Jack Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2 Plug/Jack Locator Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-10 Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-29
11 Phaser 7750 Finisher
Phaser 7750 Finisher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2 Finisher Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2 Finisher Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3 Finisher Assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-5 Internal Assemblies of the Finisher . . . . . . . . . . . . . . . . . . . . . . 11-6 Horizontal Transport Sensor, Interlock and Switch Locations . . 11-7 Finisher Sensor, Interlock and Switch Locator Map . . . . . . . . . 11-8 Finisher Sensor, Interlock and Switch Locator Map. . . . . . . . . . 11-9 Finisher Disassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-10 Horizontal Transport Assembly . . . . . . . . . . . . . . . . . . . . . . . . 11-11 Horizontal Transport Top Open, Front, and Rear Cover . . . . . . 11-12 Horizontal Transport Entrance Upper Cover Assembly . . . . . . 11-13 Horizontal Transport Belts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-14 Horizontal Transport Entrance Sensor and Top Tray Full Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-15 Gate-In Solenoid Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-16 Finisher Covers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-17 Stack Height-Sensor Assembly . . . . . . . . . . . . . . . . . . . . . . . . 11-19 Stacker Paper-Sensor Assembly . . . . . . . . . . . . . . . . . . . . . . . 11-20 Set Clamp Clutch and Gear . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-21 Eject Roll Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-22 Finisher Control Board, Bracket and Shield . . . . . . . . . . . . . . . 11-23 Stacker Motor Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-25 Paddle Shaft. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-26 Paper Transport Motor (Motor Assembly Main) . . . . . . . . . . . 11-27 Cam Bracket Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-28 Staple Unit Assembly and Motor . . . . . . . . . . . . . . . . . . . . . . . 11-29 Compiler Tray . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-30 Finisher Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-31 Finisher Service Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-42 PL 17.1 Finisher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-42 PL 17.2 Gate Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-44 PL 17.3 Horizontal Transport Assembly: 1 of 2 . . . . . . . . . . . . 11-45 PL 17.4 Horizontal Transport Assembly: 2 of 2 . . . . . . . . . . . . 11-46
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Phaser 7750 Printer
PL 17.5 Covers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PL 17.6 Top Cover and Eject Roll . . . . . . . . . . . . . . . . . . . . . . . PL 17.7 Paper Transport: 1 of 2 . . . . . . . . . . . . . . . . . . . . . . . . PL 17.8 Paper Transport: 2 of 2 . . . . . . . . . . . . . . . . . . . . . . . . PL 17.9 Staple Unit Assembly . . . . . . . . . . . . . . . . . . . . . . . . . PL 17.10 Compiler Tray Assembly . . . . . . . . . . . . . . . . . . . . . . PL 17.11 Stacker Elevator Assembly. . . . . . . . . . . . . . . . . . . . PL 17.12 Exit Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PL 17.13 Electrical Components . . . . . . . . . . . . . . . . . . . . . . . PL 17.14 Finisher Rack (Stand) . . . . . . . . . . . . . . . . . . . . . . . .
11-48 11-50 11-52 11-54 11-56 11-58 11-60 11-62 11-64 11-66
A Appendix
Menu Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2 Service Diagnostic Menu Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4 Service Usage Profile Status Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5 Missing Chain Link Codes Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . A-11 Paper Weight Equivalence Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-12
Index
Service Manual
xix
xx
Phaser 7750 Printer
General Information
In this chapter...
Phaser 7750 Printer Configurations Parts of the Printer Phaser 7750 Front Panel Configuration Image Processor Board and Rear Panel Host Interface Routine Maintenance Items and Consumables Printer Specifications
Chapter
1
Printer Introduction and Overview
The Xerox Phaser 7750 Color Laser Printer Service Manual is the primary document used for repairing, maintaining, and troubleshooting the printer. To ensure understanding of this product, complete the Xerox Phaser 7750 Printer Multi-Media Service Training and Self-Study Guide.
7750-234
1-2
Phaser 7750 Printer Service Manual
Phaser 7750 Printer Configurations
A replaceable "Configuration Chip" holds configuration information that enables or disables built-in features as described below.
Printer Configurations Features 7750B
Processor and Clock Rate (Mhz) Max Print Speed (Letter/A4) Maximum Memory (GB) Memory Configuration (MB) Resolutions (dpi) Post Script Fonts PCL5c Fonts Direct PDF 1.4 Support Job Pipelining Hard Drive Productivity Features* Full-Bleed Capability and Banner-Size* Printing Photo Mode* Automatic 2-Sided Printing* 1500-Sheet Lower Tray Deck 2500-Sheet High-Capacity Feeder Ethernet Interface (Networking) USB 2.0 Hard Drive Finisher PhaserMatch Version 3.0 Software PhaserCal Software *Requires 7750B to 7750DN upgrade. G4 715 35/35 1 256
7750DN
G4 715 35/35 1 384
7750GX
G4 715 35/35 1 512
7750DXF
G4 715 35/35 1 512
Base memory allows 1200 x 1200 dpi, full-clip path A3 image. 137 81 Std Std N/A* N/A* N/A* N/A* Opt Opt N/A* Std Std N/A N/A Opt 137 81 Std Std Std Std Std Std Opt Opt 10/100 Std Std Opt Opt Std 137 81 Std Std Std Std Std Std Std N/A 10/100 Std Std Opt Std Std 137 81 Std Std Std Std Std Std N/A Std 10/100 Std Std Std Std Std
General Information
1-3
Parts of the Printer
Exterior - Front View
5 1 6
7 2 8 3 9
4
7750-445
1. Face Down Tray 2. Front Door 3. Tray 1 (MPT) 4. 2500-Sheet High-Capacity Feeder (1500-Sheet Lower Tray Deck not shown) 5. Power Switch
6. Finisher Top Door H Release 7. Finisher Output Tray 8. Finisher Door J 9. Front Door right side release (release on left side not shown
1-4
Phaser 7750 Printer Service Manual
Exterior - Rear View
1 5
2 6
3 4
7750-446
1. USB Connection 2. Ethernet 10/100 Base-T Connection 3. GFI Reset Button
4. AC Power Cord Connection 5. Latch for Left Door A 6. Tray 1 (MPT) in closed position
General Information
1-5
Phaser 7750 Front Panel Configuration
The printer's front panel consists of one LED, a display window, and six buttons. These buttons are used to navigate the menu system, perform functions, and select modes of operation for the printer.
LED Indicators:
Green = Ready to Print Flashing Yellow = Warning
Flashing Green = Receiving, Processing Data, Printing or Power Saver Mode Flashing Red (Continuously) = Error
Front Panel Button Descriptions
3 5
Phaser 7750
Tray 2 Paper Type
Plain Paper Heavy Plain Paper Phaser Series-25 Premium Transparency Exit
1
1 2 3 4
LED (Power/Status) Graphic front panel display Cancel button Back button
2
4
5 6 7 8
6
7
8
7750-447
Up button - scrolls up the menu system Down button - scrolls down the menu system OK (select) button Information "i" button - for additional explanation or help
Front Panel Shortcuts
Mode
Skip execution of POST diagnostics Print Service Diagnostics Map Reset PostScript NVRAM Password Bypass Enter Service Diagnostics
Press this selection at Power On
OK INFO BACK+OK UP+DOWN BACK+INFO
1-6
Phaser 7750 Printer Service Manual
Image Processor Board and Rear Panel Host Interface
The components on the image processor board are illustrated in the following figure.
6 2 4 1 5
7 8 3
7750-170
1. RAM (SODIMM) 2. RAM (SODIMM) 3. USB Connector 4. Health LEDs 5. Hard Drive
6. Processor Fan 7. NVRAM 8. Ethernet Connector
General Information
1-7
Routine Maintenance Items and Consumables
6 2 1 3 4 7
5
7750-449
Routine Maintenance Items
1. Transfer Roller 2. Fuser 3. Belt Cleaner Assembly 4. Imaging Units 5. Waste Cartridge
Consumables
6. Toner Cartridges
Service Parts
7. Accumulator Belt
Consumable capacity is based on 5% per color on A4/Letter paper. Routine Maintenance Item capacity is based on A4 @ 5%. Routine Maintenance: Transfer Roller Imaging Units Fuser Unit Waste Cartridge Service Parts: Accumulator Belt Lifetime (480,000 - coverage independent) 100,000 30,000 A4 images 60,000 27,000 Consumables: Cyan Toner Magenta Toner Yellow Toner Black Toner 22,000 22,000 22,000 32,000
1-8
Phaser 7750 Printer Service Manual
Printer Specifications
Physical Dimensions and Clearances
Print Engine Dimensions
Height: Width: Depth: Weight:
Value
493 mm (19.4 in.) 644 mm (25.4 in.) 715 mm (28.15 in.) 91 kg (200 lbs.)
2500-Sheet High-Capacity Feeder Dimensions
Height: Width: Depth: Weight:
Value
364 mm (14.3 in.) 644 mm (25.4 in.) 682 mm (26.9 in.) 40 kg (88 lbs.)
1500-Sheet Lower Tray Deck Dimensions
Height: Width: Depth: Weight:
Value
364 mm (14.3 in.) 644 mm (25.4 in.) 682 mm (26.9 in.) 30 kg (66 lbs.)
Clearances - For the optional finisher clearances, see "Phaser 7750 Finisher" on page 11-1
10.0 cm (4.0 in.)
5.0 cm (1.96 in.)
36.8 cm (14.5 in.) 160.4 cm (63.1 in.)
42.5 cm (16.7 in.)
106.1 cm (41.8 in.)
7750-224
General Information
1-9
Mounting Surface Specification
These specifications apply to any Phaser 7750 printer used as a table-top printer, without a lower tray assembly or cart. There are 4 feet on the bottom of the printer. The right hand side of the printer is more susceptible to problems due to foot placement. 1. In order to function properly, the printer must be located on a surface with the following minimum dimensions. All 4 feet must rest squarely on the mounting surface.
485 mm Min 19.10 in
530 mm Min 20.87 in
7750-339
2. Mounting surface flatness must be within the range shown in the following figure.
Right Hand Side 5mm Max
7750-340
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Phaser 7750 Printer Service Manual
3. The printer must not be tipped or tilted more than is shown in the following figure.
5mm Max
7750-341
Failure to adhere to these mounting specifications will void all guarantees of print quality and/or performance. Known problems that can occur as a result of exceeding the mounting surface specifications are:
Color-to-Color mis-registration, primarily in the horizontal (laser scan) direction. A smear or band of toner approximately 40 mm from the trailing edge of the print.
General Information
1-11
Functional Specifications
Characteristic
Printing process Color medium Resolution / Print Modes
Specification
The Phaser 7750 printer uses lasers with an electrophotographic four-color (CMYK) single pass print process. Four color toner cartridges: Cyan, Yellow, Magenta, and Black EAHG Toner Standard: 1200 x 600 dpi OHP: 1200 x 600 dpi Enhanced: 1200 x 1200 dpi Photo: 1200 x 1200 x 1-bit under color < 11 seconds color <10 seconds monochrome Warm up time to Ready from power on or ENERGY STAR, 40 seconds. First page out from Ready, 7.4 seconds mono, 6.7 seconds color.
First Page-Out (Letter/ A4) Warm-up time
Print Speeds
Ltr/A4 Duplex
28 18 N/A N/A
Speeds
Standard 1200 x 600 dpi Photo 1200 x 1200 dpi OHP Card Labels
Ltr/A4
35 22 8 11 N/A
Tab/A3
17 11 N/A 9 N/A
Tab/A3 Duplex
13/13 8 N/A N/A
Electrical Specifications
Characteristic
Primary line voltages Frequency range Power consumption
Specification
115/127 VAC 10 A 200/240 VAC 5 A 50/60 Hz (+/- 3 Hz) Power saver: 45 watts Standby: 130 watts Ready: 220 watts Continuous Printing: 220 to 600 watts average Peak (warming up): 1100 watts
1-12
Phaser 7750 Printer Service Manual
Environmental Specifications
Characteristic
Temperature:
Specification
Operating: 10 to 32o C Storage: -20 to 50o C
Humidity Altitude Acoustic Noise
Normal operating: 10 to 85% relative humidity Optimum operating: 25 - 75% 0 to 2500 m (8000 ft.) Idle: 29 dB(A) Printing: 52 - 53 dB(A)
Media and Tray Specifications
For information on approved Phaser 7750 media and paper types, print the "Paper Tips Page" from the printer's front panel.
General Information
1-13
1-14
Phaser 7750 Printer Service Manual
Theory of Operation
In this chapter...
Summary of the Phaser 7750 Print Process Paper Path of the Printer EAHG Toner Technology Overview ROS and Regicon Technology Overview RegiCon Overview Sensors
Chapter
2
Summary of the Phaser 7750 Print Process
The Phaser 7750 Color Laser Printer is a `full-color laser printer', that utilizes electrophotographic recording principles to place a full color image onto the print media. The system contains a drum and developing unit for each color (yellow, magenta, cyan and black (YMCK), and places the toner image of each color onto print media via an intermediate transfer belt, producing full-color prints. A summary description of the printing process is presented in the following steps: 1. Charging: The imaging unit charge roller is negatively charged by the HighVoltage Power Supply (HVPS) and is kept in contact with the drum surface to provide a uniform negative charge on the drum as it rotates at a constant speed. This occurs simultaneously for YMCK. 2. Exposure: The laser unit emits laser beams modulated by image data from the Image Processor board. The laser beams are directed onto the drum surface through a system of mirrors and lenses. A rotating polygonal mirror causes the laser beams to scan the drum surface from end to end (axially) as it rotates. The beams are turned on to print a pixel and off when no printing is required. The negative charge on the drum surface is reduced at each point where the energized laser beam strikes, to form an electrostatic latent image on the drum surface. This process is performed simultaneously for YMCK. 3. Development: Toner is electrostatically attracted to the invisible latent image on the drum surface to form the visible image on the drum. Toner is fed into the developer using the agitator and auger. The toner and the carrier in the developer form a layer on the magnet roller in the developer. The magnet roller turns against the surface of the drum and is kept at a constant negative potential. At areas on the drum surface where the negative charge has not been reduced by the laser light, potential between the drum and the toner particles is lower than that between the magnet roller and the toner particles. At areas where the drum charge has been reduced, the potential between the particles and drum is higher than between the magnet roller and toner particles are attracted to the drum. A thin semiconductive sleeve on the magnet roller is vibrated by an AC voltage to encourage migration of the toner particles to the drum. When the toner particles attach to the drum, the negative charge of the particles reduces drum potential at that point, thus reducing the attraction of additional toner particles. This process is performed simultaneously for YMCK. 4. Primary Transfer (Drum --> Accumulator Belt): All four toner images, formed on the individual drum surfaces, are transferred to the accumulator belt sequentially to create a complete, 4-color toner image. The accumulator belt is conductive and receives a high positive charge from the HVPS. The negatively charged toner image on each drum surface is attracted by the high positive potential and transfers to the accumulator belt. During this transfer, the remaining negative charge on the drum is neutralized by the high positive charge on the belt. 5. Cleaning: The drum cleaner consists of a blade and a brush in contact with the drum after the point where the toner is transferred to the accumulator belt. The cleaner brush receives a high positive voltage from the HVPS allowing it to electrically attract any toner particles remaining on the drum. Toner remaining on the accumulator belt after the image transfer to the print media is removed by the belt cleaner assembly and transferred to the waste bin.
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Phaser 7750 Printer Service Manual
6. Secondary Transfer: The image on the accumulator belt is transferred onto the print media using the voltage supplied by the transfer roller. The conductive transfer roller receives a high positive voltage from the HVPS that puts it at a higher potential than the accumulator belt. Since the transfer roller is located behind the print media, the 4-color toner image is attracted to the lower potential and transfers to the surface of the print media. 7. Cleaning: The accumulator belt cleaner consists of a cleaner blade in contact with the accumulator belt surface after the point where the toner is transferred to the print media. Toner remaining on the accumulator belt after the image transfer to the print media is stored in the waste cartridge. 8. Fixing: The finished toner image is unstable and easily smeared. To fuse the image, the print media goes through the fuser assembly where it passes between a pressure belt and the heat roller. The toner is fused onto the print media by the combination of heat and pressure.
Theory of Operation
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Paper Path of the Printer
The Phaser 7750 printer has a C-shaped paper-handling path. The design helps it achieve high production outputs. The paper paths available for the paper exiting the fuser are:
Straight to the Output Tray in the Top Cover (facedown). Straight to the optional Finisher. Paper can be inverted for 2-sided printing.
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Trays 1-5
The paper trays consist of four main trays and one Multi-Purpose Tray on the side of the printer. Tray 1 (MPT) is located on the left side of the machine and allows feeding of specialty media stock, envelopes, and custom size paper. On the GX configuration, Trays 2, 3, 4, and 5 are identical and can be interchanged. On the DXF configuration (not shown), Trays 2 and 3 are identical and can be interchanged. Trays 4 and 5 are the high-capacity feeder paper trays.
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Paper Size Sensing
Trays 2 through 5 automatically sense the standard size media loaded in the printer by using the paper size sensors mounted on the back inside of the printer. When paper is loaded in the tray and the paper guides are adjusted, the levers on the bottom of the trays change the size sensor actuator locations. Actuating different combinations of the paper size sensors produces different combinations of high and low signals, which tell the printer logic what size of paper to display on the front panel, once the tray has been re-inserted into the printer. Tray presence is also detected by the paper size sensor. Any actuation of the paper size sensor signals the tray is present.
Paper Feeding and Sensing
Note The tray feed / lift motor is a dual purpose motor, providing both the paper feed and tray lift drive functions. When the control logic calls for paper feed, the pick roller moves a sheet of paper to the nip of the feed rollers and retard rollers. The rollers feed the paper to the takeaway roller in the vertical transport where it is stopped and registered at the registration roller.
Registration Roll Registration Sensor Tray 2 Feed Out Sensor Takeaway Sensor Tray 4 Feed Out Sensor Tray 5 Feed Out Sensor Takeaway Roll 2 Feed Roller Retard Roller Pick Roll
Tray 2-5 Paper Path
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Theory of Operation
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Stack Height Sensing
The pick roller feeds the paper to the paper path. As paper continues to feed, the stack height drops. When it reaches a certain level an actuator unblocks the stack height sensor. The control logic then stops paper feed and raises the paper tray. This causes the actuator flag to block the stack height sensor again which signals the control logic to resume feeding paper. The stack height sensing operates the same way for Trays 2, 3, 4, and 5.
Paper Present Sensing
When the last sheet is fed from any of the four main trays, the no paper sensor actuator drops into an opening in the paper tray and unblocks the no paper sensor.
Tray 1 (MPT) Loading and Feeding
Tray 1 Solenoid Tray 1 Feed Roll Tray 1 No Paper Sensor
Tray 1 Takeaway Roll
Registration Clutch Registration Roll Registration Sensor OHP Sensor Takeaway Clutch
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When media is placed in Tray 1, the lead edge deactuates the Tray 1 no paper sensor. The sensor signals the control logic that paper is present. When the last sheet of paper is fed from the tray the actuator drops through the opening of the tray and activates the sensor. When the user prints from Tray 1, the control logic supplies mechanical drive to the feed roller and nudger. When the control logic calls for paper feed, it sends a feed signal to momentarily energize the Tray 1 solenoid causing the feed roller to pivot down. When the pick roller contacts the paper, a sheet is fed into the nip between the feed roll and the takeaway roll.
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2-Sided Printing
Inverter Forward Clutch Exit Roll Full Paper Stack Sensor
Inverter Reverse Clutch
Face Down Tray
Fuser Exit Switch Fuser Exit Roll Exit Gate Fuser Assy
FUSER
ACCUMULATOR BELT
Regi. Roll Regi. Clutch
Registration
Regi. Sensor
Main Motor Duplex Motor
MPT
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Paper leaving the fuser can be directed to the top output tray or the finisher. If 2-sided (duplex) printing has been selected, paper can be directed through the inverter transport and into the duplex transport. The duplex paper path reverses the direction of paper travel and the duplex gates direct the paper through the inverter and into the duplex transport. An image can then be placed on the second side of the media.
Theory of Operation
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Fuser
The fuser receives its drive from the main motor. After the toner images are applied to the paper, the paper is then passed through the fuser. The fuser belt is pressed against the heat roller to melt the toner and bond it to the paper. The fuser belt is always spring loaded against the heat roller, but can be released for jam clearance. The flexibility of the belt (versus a pressure roller) provides a longer contact time and a larger area of contact with the heat roller, thereby providing better fusing.
Fuser Life Expectancy
The life expectancy of the fuser is 60,000 letter/A4 size pages. Several factors can reduce the life of the fuser:
Greater than 5% coverage Paper use larger than letter size Printing on heavy media Printing short-edge feed Printing on transparencies or specialty media
Three fuses on the fuse board in the fuser assembly are used in conjunction with a PostScript algorithm to determine the life used. Fuses are blown in the reverse order than they were on the Phaser 7700 (3,2,1 instead of 1,2,3). Fuse #3 is blown after 100 prints are made. Fuse #2 is blown at 50% of life and fuse #1 is blown at 99% of life used. If fusers are swapped between printers and don't have the exact same configuration of blown and closed fuses the printer will make a fuser life assumption based on which fuses are closed and then set the fuser life using that assumption after 100 prints are run. All fuses closed, new fuser. Fuse 3 open, fuse 2 and 1 closed, life will be set at 25% used. Fuse 3 and 2 open fuse 1 closed, life will be set at 75% used. All fuses open, life is set at 99% used.
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Phaser 7750 Printer Service Manual
EAHG Toner
EA (Emulsion Aggreate High Gloss) toner is a relatively new type of toner with particles that are more spherical and uniform in size. This toner will be used for all Phaser 7750 Printer applications. The image below shows the EA toner particles. The small bumps are particles of additives that produce some of the characteristics of the new toner.
The image below shows some DC12 conventional toner. Like the EA toner, the small bumps on the outside of the toner particles are additives that are used to provide specific characteristics.
Theory of Operation
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Technology Overview
Standby Power
There are two types of standby power in this machine: switched AC and switched DC. Switched power requires that both the circuit breaker and the printer's main power switch be in the ON position.
Switched AC Power - This is the control signal whose power off transition is delayed to allow the second bias transfer roller to retract. Switched DC Power - Switched AC power from the AC Drive PWB goes to the low voltage power supplies for the printer. Whenever switched AC power is provided to the three low voltage power supplies, their output DC voltages are activated by a 5 VDC signal.
Machine Run Control and NVRAM
Machine control centers on the following:
Engine Control Board Image Processor Board Image Processor NVRAM Engine NVRAM
Image Processor Board Engine Control Board
Machine parameters are held by non-volatile memory located in two places:
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Drive Power
The Drive Power subsystem includes five motors and their driven assemblies.
Main Motor - The main motor provides the drive for paper feed, black developer housing, and the fuser. The main motor gets 24 VDC power from the +24 Volt power supply by way of the interface board. The motor enable and speed control signals come from the microprocessor on the engine control via the interface board. Accumulator Belt Motor - The accumulator belt motor turns the drive roller for the accumulator belt and the accumulator belt cleaner auger. Transfer Roller Motor - Engages and retracts the transfer roller. Developer Motor - The developer motor provides the drive for the C, Y, and M developers.
Theory of Operation
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Imaging Unit Motors - There are two imaging unit motors providing drive to the four imaging units: one drives the Y, M, and C drums, and the other drives the K (black) drum. Like the main motor, the drum motors get 5 and 24 volt DC power from 5 and 24 volt power supplies via the interface board. The motors are enabled and the speed is controlled by the engine control board.
Main drive assy
Black Imaging Unit motor (K) (hidden)
Developer drive assy Imaging Unit drive assy Accumulator belt drive assy
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System Power Supplies
The System Power Supplies consist of: the T1, T2, and T3 HVPS, the 24 Volt LVPS, 3.3 VDC LVPS, and the (2) 5VDC LVPS.
Engine Control Interface Board High Voltage Power Supply/ T1 Board High Voltage Power Supply/ T3 Board High Voltage Power Supply/ T2 Board
GFI AC Drive Board Noise Filter Board
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Theory of Operation
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24 V Low Voltage Power Supply 24 V Low Voltage Power Supply Fan
AC Power Chassis 3.3 V Low Voltage Power Supply
5 V Low Voltage Power Supply
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ROS and Regicon Technology Overview
The locations of the ROS and the ROS shutter solenoid are shown in the following figure.
There are four ROS shutters (not shown). The ROS module is field replaceable and contains four laser diodes, one polygon motor/mirror, and several lenses and mirrors. The ROS module "reflects" the four laser beams so that they strike the Imaging Units correctly. The ROS module contains four mirrors that can be adjusted for skew using RegiCon. This adjustment MUST be made when the ROS is replaced. NEVER remove the cover from a ROS module for ANY reason contamination will result.
Write Black Process
The Phaser 7750 Printer uses a "black writing" process for exposing the imaging units. In the write black process, the image areas are discharged, or exposed. Because the image area is normally much smaller than the background area, the Write Black approach extends the life of the laser diode. In the Write Black process, the negative toner particles are attracted to the more positive image areas on the photoreceptor and repelled by the higher negatively charged background areas. A negative developer bias voltage assures good development of the image areas.
Theory of Operation
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In the Write Black process for the Phaser 7750 printer, the four individual images, one in each color, are transferred to the surface of the accumulator belt.The second transfer roller puts a positive charge on the copy paper. Then the four-color image is transferred to the sheet of paper in one pass. The positive charge attracts the negative toner particles from the accumulator belt to the copy paper. The image data is processed through the image processor board and is then routed to the engine control board. On the image processor board, the process of screen generation is conducted. In this process, the incoming image data is arranged in a screen pattern before being sent to the ROS (Laser). The engine control board is the ROS driver board. In other words, it is the last location in the imaging path before the image data becomes optical information in the form of modulated laser beams. In the case of the Phaser 7750 printer, the engine control board sequentially passes data that comprises the 4 different color planes to the Laser Diodes in the ROS. The color planes are digital at this time, that is, they are a stream of 1's and 0's. The digital information is applied to the ROS control circuit to turn the laser diodes on and off. (A 0 turns the laser on and a 1 turns it off.) Using this technique, the digital levels that make up the image data are modulated onto the laser beams. As each of the four laser diodes scans the surface of the drum (in the YMCK sequence), the image data is reflected and collimated within the ROS and is finally reflected out to each imaging unit where the charged photoreceptor is exposed by the laser. As the laser beam scans across the photoreceptor, a latent image is created on the surface of the drum. As the i