Brother HL-3450CN Service Manual
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Brother HL-3450CN Service Manual

Brother HL-3450CN Service Manual

Color laser printer
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Brother Color Laser Printer

SERVICE MANUAL

MODEL: HL-3450CN
Read this manual thoroughly before commencing any maintenance work.
Keep this manual in a convenient place for quick and easy reference at all times.
January, 2002
SM-PRN028

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Summary of Contents for Brother HL-3450CN

  • Page 1: Service Manual

    Brother Color Laser Printer SERVICE MANUAL MODEL: HL-3450CN Read this manual thoroughly before commencing any maintenance work. Keep this manual in a convenient place for quick and easy reference at all times. January, 2002 SM-PRN028...
  • Page 2 Specifications are subject to change without notice. Trademarks: The brother logo is a registered trademark of Brother Industries, Ltd. Apple, the Apple Logo, and Macintosh are trademarks, registered in the United States and other countries, and True Type is a trademark of Apple computer, Inc.
  • Page 3 HL-3450CN SERVICE MANUAL PREFACE This service manual contains basic information required for after-sales service of the color laser printer (here-in-after referred to as "this machine" or "the printer"). This information is vital to the service technician to maintain the high printing quality and performance of the printer.

  • Page 4: Table Of Contents

    TABLE OF CONTENTS TABLE OF CONTENTS REGULATIONS..................vi SAFETY INSTRUCTIONS ..............viii SHIPMENT OF THE PRINTER............xiii CHAPTER 1 PRODUCT OUTLINE ..........1-3 1. FEATURES.....................1-3 2. PARTS NAMES & FUNCTIONS ..............1-6 3. INTERNAL STRUCTURE ................1-8 4. DESCRIPTION OF CONTROL PANEL ............1-9 4.1 Video Controller Mode ......................1-9 4.2 Engine Controller Mode .......................1-9 CHAPTER 2 SPECIFICATIONS............
  • Page 5 HL-34500CN SERVICE MANUAL CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS....4-3 1. BASIC STRUCTURE ..................4-3 1.1 Mechanical Structure ......................4-3 1.2 Basic Mechanism of Color Printing ..................4-5 1.3 Structure of the OPC Belt ....................4-7 1.4 Print System and Transfer System ..................4-8 1.5 Scanning System .......................4-23 1.6 Paper Transportation System ....................4-25 1.7 Fusing Unit .........................4-26 2.
  • Page 6 TABLE OF CONTENTS 2.5 Cleaning the Paper Discharger ..................6-13 2.6 Cleaning the OPC Belt Cartridge ..................6-14 2.7 Cleaning the Transfer Drum....................6-15 2.8 Cleaning the Dustproof Glass in the Laser Unit..............6-16 2.9 Cleaning the Printer Interior ....................6-17 2.10 Cleaning the Oil Pad ......................6-18 3.
  • Page 7 HL-34500CN SERVICE MANUAL CHAPTER 8 TROUBLESHOOTING ..........8-3 1. OUTLINE OF TROUBLESHOOTING .............8-4 2. OPERATOR CALL..................8-5 2.1 Video Controller Mode ......................8-5 2.2 Engine Controller Mode .......................8-8 3. PAPER TRANSPORT ERROR..............8-10 3.1 Feed Jam ...........................8-10 3.2 Inner Jam ...........................8-11 3.3 Outer Jam ..........................8-13 3.4 Others ..........................8-13 4.

  • Page 8: Regulations

    REGULATIONS REGULATIONS LASER SAFETY (FOR 110-120 V MODEL ONLY) This printer is certified as a Class I laser product under the U.S. Department of Health and Human Services (DHHS) Radiation Performance Standard according to the Radiation Control for Health and Safety Act of 1968.
  • Page 9 HL-3450CN SERVICE MANUAL IEC 60825 SPECIFICATION (FOR 220-240 V MODEL ONLY) This printer is a Class 1 laser product as defined in IEC 60825 specifications. The label shown below is attached in countries where required. This printer has a Class 3B Laser Diode which emits invisible laser radiation in the Scanner Unit. The Scanner Unit should not be opened under any circumstances.

  • Page 10: Safety Instructions

    SHIPMENT OF THE PRINTER SAFETY INSTRUCTIONS SAFETY PRINCIPLE 1) Before starting any operations, read this manual thoroughly. Especially read the safety instructions in this section carefully and ensure that you understand the contents. 2) Perform all the operations by following the procedures described in this manual. Follow all the cautions and warnings set out in the procedures and on safety labels affixed to the machine.
  • Page 11 HL-3450CN SERVICE MANUAL WARNING HAZARDOUS VOLTAGE May cause serious injuries or fatal accidents. Voltage is now applied from the power supply of printer. There is a danger of electrical shock if you touch the active area inside the printer. Be sure to turn the power supply switch OFF and pull the plug out from the power outlet before starting maintenance work on the printer.
  • Page 12 SHIPMENT OF THE PRINTER CAUTION HAZARDOUS POWDER Toner is a fine powder which can cause a powder explosion if disposed of into a fire. Under no circumstances dispose of toner into a fire. CAUTION HAZARDOUS POWDER Toner is a fine powder which may cause irritation to the eyes and respiratory organs if inhaled.
  • Page 13 HL-3450CN SERVICE MANUAL CAUTION Do not lean against or apply any excessive force to the paper cassette, open cover of Duplex unit. Otherwise it may cause the product to decline or fall down and result in the injuries.

  • Page 14: Laser Caution Label

    SHIPMENT OF THE PRINTER <Label Location> 1. Hot Caution Label WARNING WARNUNG AVERTISSEMENT Hot surface. Heiße oberfiäche. Surface chaude. Avoid contact. Bei beseitigung. Eviter tout contact. 2. Laser Caution Label 7 8 0 n m - 8 0 0 n m DANGER- INVISIBLE LASER RADIATION WHEN OPEN.
  • Page 15 HL-3450CN SERVICE MANUAL 3. Rating Label (For US) (For Europe) 4. Operation Label 5. Jam Label xiii...

  • Page 16: Shipment Of The Printer

    SHIPMENT OF THE PRINTER SHIPMENT OF THE PRINTER If for any reason you must ship the printer, carefully package the printer to avoid any damage during transit. It is recommended that you save and use the original packaging. The printer should also be adequately insured with the carrier.

  • Page 17: Chapter 1 Product Outline

    HL-3450CN SERVICE MANUAL CHAPTER 1 PRODUCT OUTLINE...
  • Page 18 CHAPTER 1 PRODUCT OUTLINE CONTENTS CHAPTER 1 PRODUCT OUTLINE ............. 1-3 1. FEATURES......................1-3 2. PARTS NAMES & FUNCTIONS ................1-6 3. INTERNAL STRUCTURE ..................1-8 4. DESCRIPTION OF CONTROL PANEL ............... 1-9 4.1 Video Controller Mode......................... 1-9 4.2 Engine Controller Mode....................... 1-9...

  • Page 19: Features

    It is fully compatible with the industry-standard bi-directional parallel interface. The Brother network board (NC-4100h) is factory installed in the HL-3450CN, which enables you to use this printer in the TCP/IP, IPS/SPX, Apple Talk, DLC/LLC, Banyan VINES, DEC LAT and NetBEUI environments.
  • Page 20 ® The printer can emulate Hewlett-Packard Color PCL 5C language (PCL6 in monochrome ® mode), PostScript 3 language emulation (Brother BR-Script 3) printers, the industry- ® ® ® standard HP-GL™ plotter as well as EPSON FX-850™, and IBM Proprinter XL printers (in monochrome mode).
  • Page 21 Type of toner used Effective final resolution Dot structure/halftones For optimal results, it is recommended that the following materials and settings are used. 1) NEUSIEDLER color copy paper 2) Brother Toner Cartridges TN-02 BK/C/M/Y 3) 600 x 600 dpi resolution...

  • Page 22: Parts Names & Functions

    CHAPTER 1 PRODUCT OUTLINE PARTS NAMES & FUNCTIONS <Front View> 1. Upper cover 2. Control panel 4. Top cover (Paper Exit Unit) 5. Power button 3. Front cover Media cassette Fig. 1-1 <Rear View> Paper exit unit 8. Controller box 6.
  • Page 23 HL-3450CN SERVICE MANUAL Part Name Outline of Functions To act as an upper enclosure and also as a Upper cover paper tray for printed paper. To display the status of printer operations and Control panel control the printer directly. To act as a front enclosure, opened when Front cover replacing a toner cartridge or waste toner pack.

  • Page 24: Internal Structure

    CHAPTER 1 PRODUCT OUTLINE INTERNAL STRUCTURE <Cross Sectional View > 2. OPC Belt Cartridge 3. Drum Cleaner 1. Toner Cartridge 4. Fusing Unit (K, Y, M, C) 11. Laser Unit 9. Media Cassette 7. Paper Discharger 8. Transfer Roller 5. Transfer Unit 6.

  • Page 25: Description Of Control Panel

    HL-3450CN SERVICE MANUAL DESCRIPTION OF CONTROL PANEL The printer control panel provides control of the printer including test printing, maintenance operations performed by the video controller and also the ones which are performed by the engine controller. The Video Controller Mode and the Engine Controller Mode have some common functions.
  • Page 26 CHAPTER 1 PRODUCT OUTLINE Power Ready Data Alarm Cancel Secure Print Menu Reprint Back Fig. 1-4 LED / Button Name LCD: 16 character by 2 lines Power LED Ready LED Data LED Go button Job Cancel button Alarm LED Secure Print button - button + button Reprint button...

  • Page 27: Chapter 2 Specifications

    HL-3450CN SERVICE MANUAL CHAPTER 2 SPECIFICATIONS...
  • Page 28 CHAPTER 2 SPECIFICATIONS CONTENTS CHAPTER 2 SPECIFICATIONS............2-3 1. RATING ......................2-3 2. GENERAL SPECIFICATIONS ................2-4 2.1 Printing ............................2-4 2.2 Functions ............................ 2-4 2.3 Electrical and Mechanical......................2-5 2.4 Paper ............................2-6 2.4.1 Printable media ........................2-6 2.4.2 Media cassette capacity ...................... 2-8 2.4.3 Printed output........................

  • Page 29: Rating

    HL-3450CN SERVICE MANUAL CHAPTER 2 SPECIFICATIONS RATING WARNING Use the power supply cable supplied with the printer, or a similar cable complying with the following specification (3-wire power cable with ground). Use of an “out of specification” cable may result in an electric shock.

  • Page 30: General Specifications

    Resolution 600 x 600 dots per inch (Fine) 2400 x 600 dots per inch (using HRC and CAPT) (The resolution can be enhanced to 2400dpi class by using Brother exclusive HRC (High Resolution Control) and CAPT (Color Advanced Photoscale Technology).)

  • Page 31: Electrical And Mechanical

    HL-3450CN SERVICE MANUAL 2.3. Electrical and Mechanical Power source U.S.A. and Canada: AC 120V, 50/60Hz Europe and Australia: AC 220 to 240V, 50/60Hz Power consumption Printing (peak*): 1350W or less Printing (average): 600W or less Standing by (peak*): 1350W or less...

  • Page 32: Paper

    CHAPTER 2 SPECIFICATIONS 2.4. Paper The standard media cassette (upper cassette) is supplied with the printer. The optional lower tray unit and the optional A4/Letter cassette can also be installed. NOTE: The standard upper cassettes and the optional A4/Letter cassette are interchangeable between the upper and the lower feeder.
  • Page 33 HL-3450CN SERVICE MANUAL (3) Recommended paper specifications Item Description Basis Weight (g/m 82 ± 5 Thickness (µ m) 95 ± 6 Smoothness (Bekk) (seconds) 90 ± 20 Stiffness (Clark) 100 ± 15 Brightness (%) 85 ± 2 Surface Resistance ( )

  • Page 34: Printing Area

    CHAPTER 2 SPECIFICATIONS 2.4.2 Media cassette capacity Maximum load height: 27mm (1.06 inches) Plain paper: 250 sheets of 75g/m (20lb) paper for the standard/optional A4/Letter cassette 500 sheets of 75g/m (20lb) for the optional lower cassette Envelopes : 15 sheets Transparency: 50 sheets Label: 80 sheets...
  • Page 35 HL-3450CN SERVICE MANUAL Table 2-1: Effective Printing Areas Size 210.0mm 297.0mm 203.2mm 288.5mm 3.4mm 4.23mm 8.27” 11.69” 8.0” 11.36” 0.13” 0.17” (2,480 dots) (3,507 dots) (2,400 dots) (3,407 dots) (40 dots) (50 dots) 215.9mm 279.4mm 207.44mm 271.0mm 4.23mm Ç Letter 8.5”...

  • Page 36: Print Guarantee Area

    CHAPTER 2 SPECIFICATIONS 2.5.2 Print guarantee area <Plain paper> Paper: 5mm Other: 10mm Non printable area Print Non guarantee guarantee area area Paper: 4mm Other: 10mm Fig. 2-2 <Envelope> Non printable area Non guarantee area Print guarantee 42mm area 16mm #10: 68mm #10: 68mm DL: 40mm...

  • Page 37: Environmental Conditions

    HL-3450CN SERVICE MANUAL ENVIRONMENTAL CONDITIONS Ambient Temperature / Humidity / Altitude Under Operational conditions: 10.0 32.5 C (50 ~ 90.5 F), 20 80%RH (See the figure below) Recommended Condition; 17.5 27.0 C 70%RH 17.5 20 27 30 32.5 40 Ambient Temperature ( ) C Under Non Operational conditions: 5.0...
  • Page 38 Storage and transportation environment of printer The following defines the storage and transportation environment of printers that have been packed according to Brother specification. However, this section does not cover the OPC belt cartridge, toner cartridges and developer cartridges. In particular, since consumables such as the toner cartridges and OPC belt are individually packaged, the following environmental conditions should be respected.

  • Page 39: Chapter 3 Installation

    CHAPTER 3 INSTALLATION...
  • Page 40 CHAPTER 3 INSTALLATION CONTENTS CHAPTER 3 INSTALLATION ............3-3 1. CONDITIONS REQUIRED FOR INSTALLATION........... 3-3 1.1. Environmental Conditions.....................3-3 1.2. Basic Layout of Printer Set-up Location ................3-3 2. UNPACKING....................3-5 2.1 Unpacking of Printer ......................3-5 2.2 Unpack the Starter Kit ......................3-7 3. INSTALLATION WORK .................. 3-8 3.1 Install the Oil Bottle and Fuser Cleaner.................3-8 3.2 Install the OPC Belt Cartridge ....................3-9 3.3 Install the Toner Cartridge into the Printer................3-11...

  • Page 41: Conditions Required For Installation

    HL-3450CN SERVICE MANUAL CHAPTER 3 INSTALLATION CONDITIONS REQUIRED FOR INSTALLATION Any Laser beam printer is likely to be influenced by the environment of the set-up location. If the printer is set-up in an inappropriate location, the printer may not perform as expected.
  • Page 42 CHAPTER 3 INSTALLATION Fig.3-1 shows the basic layout of the printer set-up location that is suitable for smooth operation and maintenance of the printer. Table 50cm (20") 20cm (8") 16cm (6.4") 70cm 20cm (8") (28") 70cm (28") 80cm (32") 10cm (4") Fig.

  • Page 43: Unpacking

    HL-3450CN SERVICE MANUAL UNPACKING WARNING The package containing a printer weighs approximately 66kg (145lbs), so it is too heavy for one person to carry. It needs two adults or more to move the printer. Since the printer is a precision machine, make sure that it is carried slowly with care so that no impact occurs to the printer while moving it.
  • Page 44 CHAPTER 3 INSTALLATION STARTER PACKING SLEEVE STARTER KIT PACKING (U) Media cassette OUTER BOX Toner cartridges STARTER KIT PACKING (M) STARTER KIT (ST PACKING SET 3 (B)) OPC belt cartridge Oil bottle L-SHAPED PAPER SUPPORT Toner cartridges Fuser cleaner STARTER KIT PACKING (L) BAND Power cable...

  • Page 45: Unpack The Starter Kit

    HL-3450CN SERVICE MANUAL Unpack the Starter Kit <Unpacking Procedure> Open the vinyl bag and slide off the cardboard sleeve covering the starter kit. Confirm all of the following parts are inside the starter kit packing box. Kit Name Appearance Quantity...

  • Page 46: Installation Work

    CHAPTER 3 INSTALLATION INSTALLATION WORK CAUTION Do not lean against or apply any excessive force to the media cassette or open covers; otherwise it may cause the product to tilt or fall over and result in injuries. Install the parts of the starter kit into the printer according to the following procedures: Install the Oil Bottle and Fuser Cleaner (1) Release the two sets of retainer lock levers for both the oil bottle and the...

  • Page 47: Install The Opc Belt Cartridge

    HL-3450CN SERVICE MANUAL NOTE: The retainer lock levers for the fuser cleaner and oil bottle are located as shown in the figure below; Retainer lock levers Fuser cleaner Oil bottle Retainer lock levers Fig. 3-6 Install the OPC Belt Cartridge...
  • Page 48 CHAPTER 3 INSTALLATION (2) Release the belt cartridge lock levers (left & right). Belt cartridge lock lever (L) Belt cartridge lock lever (R) Fig. 3-8 Tension (3) Pull and remove the tension release release pin pins on both sides (left & right) of the OPC belt cartridge.

  • Page 49: Install The Toner Cartridge Into The Printer

    HL-3450CN SERVICE MANUAL Install the Toner Cartridges into the Printer (1) Rock each of the cartridge 3 to 4 times through 30 to the horizontal. Fig. 3-11 (2) Pull off the tape labeled ‘REMOVE’ from Protective label the toner cartridge.

  • Page 50: Install The Media Cassette And Adaptor

    CHAPTER 3 INSTALLATION Install the Media Cassette and Adapter 3.4.1 Install the media cassette (1) Remove the cassette cover from the Cassette cover media cassette. Fig. 3-16 (2) Set the paper guide according to the print paper size. Paper guide i) Horizontal direction;...
  • Page 51 HL-3450CN SERVICE MANUAL 3.4.2 Install the envelope adapter NOTE: The specification of envelopes feedable from the envelope adapter are as follows; Capacity: 15 envelopes Size: DL (110 x 220 mm), #10 (105 x 241 mm) Envelope adapter (1) Prepare the media cassette and envelope adapter.

  • Page 52: Test Print

    CHAPTER 3 INSTALLATION Test Print Make sure the printer power button is off. Do not connect the interface cable. Fig. 3-23 Connect the AC power cord to the printer, and then plug it into the AC outlet. Fig. 3-24 Turn on the power button. Fig.
  • Page 53 HL-3450CN SERVICE MANUAL After the printer warms, the READY message will appear. NETWORK READY HL-3450CN Power Ready Data Alarm Cancel Secure Print Reprint Back Fig. 3-26 Press the Go button. The printer will print a test page. Check that the test page is printed correctly.
  • Page 54 HL-3450CN SERVICE MANUAL CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS...
  • Page 55 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS CONTENTS CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS....4-3 1. BASIC STRUCTURE ..................4-3 1.1 Mechanical Structures ......................4-3 1.2 Basic Mechanism of Color Printing ..................4-5 1.2.1 Principle of color printing ....................4-5 1.2.2 Basic color printing process ..................... 4-5 1.3 Structure of the OPC Belt .......................

  • Page 56: Chapter 4 Structure Of System Components

    HL-3450CN SERVICE MANUAL CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS BASIC STRUCTURE Mechanical Structures This laser beam color printer (hereinafter called “Printer”) consists of five mechanical systems; Print, Transfer, Scanning, Paper Transport and Control System. The printer produces color printing through the interactive operations of these five systems as shown in Fig.4-1.
  • Page 57 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Main Motor Developer Motor I/F Controller Paper Exit Paper Exit Unit Drum Cleaner Unit Toner MCTL Fusing Unit Cartridge I/F Control OPC Belt Drum Cleaning Sequence Control Operation Development Laser Control Transfer Drum Paper Discharger Transfer Unit First Transfer AC Discharger Unit...

  • Page 58: Basic Mechanism Of Color Printing

    HL-3450CN SERVICE MANUAL Control System The control system consists of the following 4 (four) control parts and runs the printer by processing the interface signals transmitted from the Host computer and interfacing to the print, transfer, scanning and transport systems.
  • Page 59 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS OPC belt Toner cartridge Transfer crum Fig. 4-3 Toner C C C M M M C C Y Y Y Y Y Y First Transfer Transfer Drum Y Y Y Y Y Y M M M C C C C C Second Transfer Paper...

  • Page 60: Structure Of The Opc Belt

    HL-3450CN SERVICE MANUAL Structure of the OPC Belt The OPC belt consists of a surface layer having a photoconductor (OPC) of organic material, the inner layer of an insulator material (PET) and an aluminum deposit layer in between. The OPC belt is located as shown in Fig.4-5 as the main part of the print system.

  • Page 61: Print System And Transfer System

    CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Print System and Transfer System Fig.4-7 shows the basic structure of the print system having the OPC belt as the main part and the transfer system having the transfer drum. Color printing is achieved by actuating in sequence each process in the print system and transfer system.

  • Page 62: Structure Of The Printer

    HL-3450CN SERVICE MANUAL 1.4.1 Structure of the printer Component Part Process Charger Charging Scanner Unit Exposing Toner cartridge Developing OPC belt cartridge Receives the Image Transfer drum Transfers the Image Erase lamp Discharges the Belt Cleaning blade Cleaning the Belt...

  • Page 63: Basic Structure Of The Printing System

    CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS 1.4.2 Basic structure of the printing system A toner image is formed through the potential of the OPC belt varying in each of the charger, exposure, development, transfer and cleaning processes. Process of Print System (See Fig.4-9.) i) The OPC belt is biased to the voltage -CBV (V) by the power supply CBV.
  • Page 64 HL-3450CN SERVICE MANUAL Variation of OPC Belt Potential (See Fig.4-10.) i) The OPC belt is initially biased to -CBV (V). ii) The OPC belt surface is evenly charged to V (V) in the charging process. iii) The potential of the exposure part of the OPC belt is reduced to -VR (V) as it is exposed to the laser beam in the process of exposing, and an electrostatic latent image is formed on the OPC belt as the result.

  • Page 65: Details Of Each Process

    CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS 1.4.3 Details of each process Charging The charging process ensures that the OPC belt is evenly charged by the charger system. Structure of the charger unit (Refer to Fig.4-8 and Fig.4-11) i) The charger unit is located as shown in Fig.4-8. ii) The charger unit consists of the case, corona wire and grid.
  • Page 66 HL-3450CN SERVICE MANUAL Exposing The exposing process means that the OPC belt surface is exposed to the laser beam to form an electrostatic latent image. Structure of scanner unit i) The scanner unit is located as shown in Fig.4-8. ii) The source of the laser beam is a semiconductor laser.
  • Page 67 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Developing The developing process means that an electrostatic latent image on the OPC belt is made visible by depositing toner onto the exposed areas of the OPC belt. Structure of the Toner Cartridge (Refer to Fig.4-8 & 4.14.) i) The toner cartridge is located as shown in Fig.4-8.
  • Page 68 HL-3450CN SERVICE MANUAL Developer roller (-CBV) + (-DBV) Toner (-CBV) OPC belt Fig. 4-15 Toner (M) Exposing Developing Fig. 4-16 4-15...
  • Page 69 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS First Transfer (Drum) The first transfer process means that the toner image on the OPC belt is transferred onto the transfer drum. Structure of the Transfer Drum (Refer to Fig.4-8.) i) The drum is located as shown in Fig.4-8. ii) Material of the drum is aluminum.
  • Page 70 HL-3450CN SERVICE MANUAL First Transfer Process (Refer to Fig.4-18.) i) The OPC belt has been through the development process and contacts and synchronizes with the transfer drum. ii) The OPC belt has been biased to the potential of -CBV (V). The potential of the transfer drum is nearly GND.
  • Page 71 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Belt Discharging (Erase Lamp) The belt discharging process means that upon completion of the drum transfer process, an LED light is radiated onto the OPC belt prior to mechanically cleaning the belt to discharge the residual charge.
  • Page 72 HL-3450CN SERVICE MANUAL Belt Cleaning The belt cleaning process means that the residual toner adhering to the OPC belt surface is mechanically scavenged. Structure of Belt Cleaning The blade for the belt cleaning is located relative to the OPC belt cartridge as shown in Fig.4-8.
  • Page 73 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Second Transfer (Paper) The second transfer process is where the toner image on the transfer drum is transferred onto the transported paper. Second Transfer Structure i) The transfer roller for the paper transfer is located as shown in Fig.4-8. ii) The transfer roller is normally kept out of contact with the transfer drum until the second transfer process starts.
  • Page 74 HL-3450CN SERVICE MANUAL Paper Discharging The paper discharging process is where the transported paper onto which the toner transfer has been completed is separated from the transfer drum by applying an AC charge to the paper. Structure of Paper Discharger (Refer to Fig.4-22.) i) The AC charger unit for discharge the paper is located as shown in Fig.4-8.
  • Page 75 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Drum Cleaning The drum cleaning process is where the residual toner on the transfer drum is removed. Structure of Drum Cleaning (Refer to Fig.4-23.) i) The drum cleaning unit is located as shown in Fig.4-8. ii) The drum cleaning brush is a semiconductor type so that the brush can clean the surface of the rotating transfer drum.

  • Page 76: Scanning System

    HL-3450CN SERVICE MANUAL Scanning System This printer employs a semiconductor laser diode as a light source. This laser diode is switched according to the transmitted image data (video signal). The generated laser light scans over the OPC belt through a polygon mirror and lens, by which method electrostatic latent images will be formed on the OPC belt.
  • Page 77 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Specification: Specification of the scanner unit is as follows; Item Specifications Rated output of laser diode 5 mW. Wave length of laser beam Approx.785nm. Scanning density 600dpi Scanning width 310mm Scanner motor speed 24,072rpm Number of polygon mirror faces 4-24...

  • Page 78: Paper Transportation System

    HL-3450CN SERVICE MANUAL Paper Transportation System 1.6.1 Outline This printer employs automatic paper feeding from the media cassette. When toner images are formed on the transfer drum through the operations of the print system and transfer system, paper is fed by the pick-up roller and transported to the register roller.

  • Page 79: Fusing Unit

    CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Fusing Unit The fusing unit employs a thermal fusing system using heater lamps in the rollers. Paper carrying the combined toner image passes between the heat rollers. Heat and pressure is applied to the paper when passing between the heat rollers so that the toner image is melted and fused onto the paper.

  • Page 80: Fusing Process

    HL-3450CN SERVICE MANUAL 1.7.2 Fusing process Silicone oil supplied from the oil bottle is applied to the surface of fuser roller. The toner image has been transferred onto the paper, but not yet fused. Transported paper passes between the heater roller and back-up roller.

  • Page 81: Structure Of The Control System

    CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS STRUCTURE OF THE CONTROL SYSTEM Basic Structure - Electrical System and Functions Most of the main electrical parts of this printer are controlled by the MCTL (engine controller) PWB. <Structure of the sequence control> The basic structure of the sequence control is shown in Fig.4-28.
  • Page 82 HL-3450CN SERVICE MANUAL Main Cooling Cooling Scanner Motor Control Motor Panel Host Computer ATC (4 pcs.) Belt Drum Sensor Sensor MCTL (Engine Controller) Sequence Control Controller Control Laser Control Temperature Control Video Controller Toner Connection Control Control Panel Control Error Clearance Program...
  • Page 83 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS <Layout & Function of the Electrical Parts> Print PCB (Refer to Fig. 4-29.) Name Function To receive the print data from the host computer, Video controller PCB convert it into image data and then send the printing image data to the MCTL PWB.
  • Page 84 HL-3450CN SERVICE MANUAL Layout of PCBs 6. Erase lamp 3. Control panel PCB (Panel PWB) 8. IOD2 PWB 10. High-voltage power supply (HVU) PCB 7. IOD1 PWB 1. Video 2. Engine controller PCB controller PCB (MCTL PWB) 4. LDU PCB 9.
  • Page 85 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Motors (Refer to Fig.4-30.) Name Code Function To drive the OPC belt and the paper Main motor transport system. To drive the toner cartridge and the Developing motor developing system. (Developer drive motor) Scanner motor To scan the laser beam To exhaust the ozone from the Ozone fan motor...
  • Page 86 HL-3450CN SERVICE MANUAL Clutches (Refer to Fig.4-31.) Name Function To feed paper by coupling the feed roller to the main gear unit at the correct timing for paper Paper feeding clutch feeding. To transport paper by coupling the register roller to...
  • Page 87 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Layout of Clutches Fig. 4-31 4-34...
  • Page 88 HL-3450CN SERVICE MANUAL Sensors Name Code Function Paper size sensor Photo sensor to detect the paper size. Photo sensor to detect when paper is Paper feeding sensor PS 1 fed from the media cassette. Photo sensor to detect that paper is...
  • Page 89 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Layout of Sensors 14. Temperature sensor 3. Paper exit sensor (Thermistor to detect) 13. Cleaning roller sensor 7. Drum jam sensor 15. Paper full sensor 10. Toner sensor 5. Oil sensor 9. Belt sensor 8.

  • Page 90: Control System - Control Of The Print Process

    HL-3450CN SERVICE MANUAL Control System - Control of the Print Process A Micro CPU mounted on the MCTL PWB controls the print processes. <Print Sequence Diagram> Main Cooling Cooling Scanner Motor Control Motor Panel Host Computer ATC (4 pcs.) Belt...
  • Page 91 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Control Block Diagram (Refer to Fig.4-33.) Name Function To control the sequence of printer Sequence Control operations. To control the temperature of the fixing Temperature Control unit. To detect the toner empty status of each Toner Empty Sensing Control toner cartridge.
  • Page 92 HL-3450CN SERVICE MANUAL Laser Drive Control Circuit Laser Drive Control Circuit (LDC) consists of the video signal input circuit, laser drive circuit, laser diode, output sensing circuit and output control circuit, as shown in Fig.4- <Operation> (1) When the video signal is received, the laser drive control circuit switches the laser diode according to the video signal data.
  • Page 93 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Control of the Fusing Temperature Each roller of the fusing unit is controlled to maintain the appropriate temperature so that toner will be fixed correctly onto the print paper. <Basic Structure of Temperature Control (Fig.4-36)> FLS: Thyristor to switch the power supply to the heat lamp.
  • Page 94 HL-3450CN SERVICE MANUAL <Basic Structure of Fuser Control> RY-1 ACOFF-P RY-1 HON-N Fusing Unit THERR ACOFF HON GA/CPU Fig. 4-36 4-41...
  • Page 95 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS To maintain the temperature for fixing of the toner at 150 C by turning the thyristor on and off. Reference temperature ( approx. 185 C) to identify that it is excessively hot inside the fusing unit. When it reaches this point, the relay RY turns off, the power supply to the heat lamp is shut down and the printer stops operating.
  • Page 96 HL-3450CN SERVICE MANUAL Interface Control <General> Interface Type The video interface handles laser image data that corresponds to dots for printing but does not store image data in a buffer. The video data signals of the input image data switches the semiconductor laser diode to form a print image.
  • Page 97 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Interface Circuit (Printer side) Table 4-1: Interface Circuit Interface Circuit Signal Name VIDEO-N VIDEO-P HSYNC-N HSYNC-P PRREQ-N COMMAND-N ID1-N ID2-N VSYNC-N IREADY-N STATUS-N KEY-STATUS-N 4-44...
  • Page 98 HL-3450CN SERVICE MANUAL Connector Pin Assignment The connector in the printer to connect to the controller board is type 128A-064S2B- L14A(DDK) or the equivalent. Table 4-2: Connector Pin Assignment Pin No. Signal Name Pin No. Signal Name PSGND PSGND PSGND...

  • Page 99: Main Pcb (Video Controller Pcb)

    CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Main PCB (Video Controller PCB) 2.3.1 Outline The main PCB consists of the circuits which perform the following functions; Receive the printing data from the computer. Convert the received data to the bitmap data such as characters or graphics. Control the engine and send the generated bitmap data as a video signal.
  • Page 100 HL-3450CN SERVICE MANUAL <Main PCB Block Diagram> +3.3v / +1.65v Regurator +3.3v Clock 66MHz(CPU,SDRAM) PQ30RV31 TMPR4955-266 Generator 33MHz(PCI) 48MHZ(GA) C8750 (TX4955 266MHz) Regurator +3.3v +1.65v PQ070XZ01Z +3.3v CPU-Address/Data MultiBUS +5v/+3.3v SLOT2 SLOT1 CDCC I/F SLOT0 DIMM +3.3v (100pin) 3slots 348MB MAX...

  • Page 101: Circuit

    CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS 2.3.2 Circuit CPU block Model name: TMPR4955-266MHz MiPS 64 bits RISC CPU manufactured by TOSHIBA Clock speed: 66.7MHz (external) / 266MHz (internal) Cache memory: 32KB (Command cache) / 32KB (Data cache) Bus width: 32 bits (external) / 64 bits (internal), Floating point unit (FPU) incorporated Appearance: 160-pin QFP...
  • Page 102 HL-3450CN SERVICE MANUAL DIMM block DIMM (Dual-Inline-Memory-Module) allows memory extension by up to 128MB in each socket. 3 DIMM sockets are available. The following type of DIMM can be installed into each slot. x Appearance: 100-pin x Memory type: SDRAM...
  • Page 103 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Fig.4-38 shows the timing of each signal after the power switch is turned on. Power On 210s MAX. IREADY-N PRREQ-N 1.0sec. MAX. 0.1sec. MIN. 3.75s 3.0sec. MAX. for Continuous Printing 15sec. MAX. VSYNC-N (K) data (C) data (M) data (Y) data...
  • Page 104 HL-3450CN SERVICE MANUAL Main PCB Circuit Diagram (1/8) CODE LJ8907001 B512137CIR (1/8) NAME 4-51...
  • Page 105 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Main PCB Circuit Diagram (2/8) LJ8907001 CODE NAME B512137CIR (2/8) 4-52...
  • Page 106 HL-3450CN SERVICE MANUAL Main PCB Circuit Diagram (3/8) CODE LJ8907001 NAME B512137CIR (3/8) 4-53...
  • Page 107 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Main PCB Circuit Diagram (4/8) LJ8907001 CODE NAME B512137CIR (4/8) 4-54...
  • Page 108 HL-3450CN SERVICE MANUAL Main PCB Circuit Diagram (5/8) LJ8907001 CODE NAME B512137CIR (5/8) 4-55...
  • Page 109 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Main PCB Circuit Diagram (6/8) CODE LJ8907001 B512137CIR (6/8) NAME 4-56...
  • Page 110 HL-3450CN SERVICE MANUAL Main PCB Circuit Diagram (7/8) LJ8907001 CODE NAME B512137CIR (7/8) 4-57...
  • Page 111 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Main PCB Circuit Diagram (8/8) LJ8907001 CODE NAME B512137CIR (8/8) 4-58...
  • Page 112 HL-3450CN SERVICE MANUAL Network Board PCB Circuit Diagram CODE LJ8107001 NAME B512058CIR 4-59...

  • Page 113: Low-Voltage Power Supply Unit

    CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Low-voltage Power Supply Unit Outputs and Use Output Terminal Rated Output +5V-1 For control of the printer +5V-1R 5.3V, 8.5A For control of the laser +5V-2 For control of the interface (7A Max.) +24V-1 +24V, 6.5A For control of printer charging.
  • Page 114 HL-3450CN SERVICE MANUAL ACN3 ACN1 TAB2 ACN4 TAB1 ACN2 Power Switch Inlet White Black Fig. 4-40 4-61...
  • Page 115 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Connector Pin Assignment ACN1 MoLex: 53313-2815 Pin # Signal Name Interface Pin # Signal Name Interface +5V-1 +5V-1 Output DCOFF2-P +5V-2D OFF Signal +5V-1 +5V-1 Output SGND Signal Ground (+5V type ground) +5V-D +5V-D Output SGND Signal Ground (+5V type ground) +5V-D...

  • Page 116: High-Voltage Power Supply Unit

    HL-3450CN SERVICE MANUAL High-voltage Power Supply Unit Outputs and Function Function Power Supply (P/S) P/S Name Approx. Output Voltage Charging CHV (-) (4.6KV) 600µA First transfer CBV (-) 200V 900V Y, M DBV (-A) 200V 400V Developing bias C, K...
  • Page 117 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Connector Pin Assignment BCN1 MoLex: 53313-1815 Pin # Signal Name Interface Pin # Signal Name Interface +24V-1 +24V-1 PGND PGND FUCHK Sensor Signal of Fuser Unit Installation PGND PGND ACVON-N AC Output ON Signal PWMON-N PCB Control ON Signal CHVON-ON...

  • Page 118: Connection Diagram

    HL-3450CN SERVICE MANUAL Connection Diagram I O D 1 P W B LOWER TRAY UNIT CONNECTION DIAGRAM To IOD2 ECN2 [LFU1] IOD3(1) CCN1 CCN3 OHP1 OHP Sensor Developer Motor Paper Empty Sensor DCN10 DCN9 Paper Size Sensor CCN2 CCN5 A673...
  • Page 119 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS Symbol and Parts Name Symbol Parts Name Symbol Parts Name LVPS Low-voltage power supply unit IOD1 IOD1 PWB DSW1 Interlock switch (Front) OHP sensor DSW2 Interlock switch (Top) PEU (PS3) Paper empty sensor DSW3 Interlock switch (Back) PT1 (PS1) Paper feeding sensor...
  • Page 120 HL-3450CN SERVICE MANUAL Connector Pin Assignment 1) DCN2: IOD1 PWB - Power Supply Unit ACN1 (28 pins) Pin No. Signal Pin No. Signal +5v - 1 DCOFF2-P +5v - 1 SGND +5v - D SGND +5v - D SGND ACSYNC - N...
  • Page 121 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS 5) DCN1: MCTL PWB - IOD1 PWB (50 pins) Pin No. Signal Pin No. Signal I/OAD2 DMON-N I/OAD1 DCOFF1-P I/OAD0 DMCLK I/ODATA3 ACVON-N I/ODATA2 CHVON-N I/ODATA1 PWMON-N I/ODATA0 CBVPWM-N LEDON-N DVB (MC) PWM-N DMRDY-N DBV (KY) PWM-N I/ODATA4 (REVI1) FCBVPWM-N...
  • Page 122 HL-3450CN SERVICE MANUAL 8) DCN6: IOD1 - Paper Size Sensor 11) DCN8: IOD1 - Lower Tray Unit Pin No. Signal Pin No. Signal +5v-D +24v-1 PSU1 PKCLLON-N PSU2 FDCLL1ON-N PSU3 PSL1 PSU4 PSL2 PSU5 PSL3 SGND PSCST1 PEL1-P 9) DCN7: IOD1 - Toner Sensor (Y, M, C, K) OCST1-N Pin No.
  • Page 123 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS 14) ECN1: MCTL PWB - IOD1 (22 pins) 18) ECN13: IOD2 - Developer Clutch (K) Pin No. Signal Pin No. Signal DCL(C) ON-P +24v-1 DCL (M) ON-P DCL (Y) ON-P DCL (K) ON-N DCL (K) ON-P PSL (KY) ON-P 19) ECN3: IOD2 - Home Position Sensor1 PSL (MC) ON-P...
  • Page 124 HL-3450CN SERVICE MANUAL 24) ECN17: IOD2 - Waste Toner Sensor 29) DCN9: IOD1 - Developer Drive Motor Pin No. Signal Pin No. Signal TBFL1-N DMRDY-N SGND DMON-N WTLEDON DMCLK SGND PGND PGND 25) ECN10: IOD2 - Cleaner Cam Clutch +24v-1 Pin No.
  • Page 125 CHAPTER 4 STRUCTURE OF SYSTEM COMPONENTS 32) ACN3: LVPS ACN3 - MCTL POCN 36)37) CNDUP: Printer - Duplex Unit Pin No. Signal Pin No. Signal +5v-2 D-COMMAND +5v-2D SGND +5v-2D DUMBUSY2-N SGND SGND SGND D-STATUS SGND SGND +24VOFF-P 33) ACN2: LVPS - Interlock Switch DUPCHK-N Pin No.

  • Page 126: Control Panel

    HL-3450CN SERVICE MANUAL CHAPTER 5 CONTROL PANEL OPERATION...
  • Page 127 CHAPTER 5 CONTROL PANEL OPERATION CONTENTS CHAPTER 5 CONTROL PANEL OPERATION ........5-3 1. PANEL LAYOUT....................5-3 2. VIDEO CONTROLLER MODE................5-4 2.1 Configuration of Operational Mode ..................5-4 2.2 Line Test Mode ........................5-5 2.3 DRAM Test Mode ........................5-9 2.4 Test Print Mode........................

  • Page 128: Chapter 5 Control Panel Operation

    HL-3450CN SERVICE MANUAL CHAPTER 5 CONTROL PANEL OPERATION PANEL LAYOUT Power Ready Data Alarm Cancel Secure Print Menu Reprint Back Fig. 5-1 LED / Button Name LCD: 16 character by 2 lines Power LED Ready LED Data LED Go button...

  • Page 129: Video Controller Mode

    CHAPTER 5 CONTROL PANEL OPERATION VIDEO CONTROLLER MODE This section describes the operation and maintenance functions in the Video Controller Mode. Configuration of Operational Mode This printer has various functions as set out in Table 5-1 for users to easily perform general test printing, general settings and some maintenance work.

  • Page 130: Line Test Mode

    HL-3450CN SERVICE MANUAL Line Test Mode This mode tests the following items; Item Self-test Description LCD TEST Displays the checker pattern LED TEST Checks that all LEDs are on / off. SW TEST Checks that all buttons work correctly. SENSOR TEST Checks that all sensors work correctly.
  • Page 131 CHAPTER 5 CONTROL PANEL OPERATION Press the Go button to implement the SW TEST. The following display appears on the LCD and the LEDs are all turned off. Check that the LEDs are turned on and the corresponding number appears as follows when pressing the buttons on the control panel in order.
  • Page 132 HL-3450CN SERVICE MANUAL Press the Go button to implement the RAM SIZE CHECK. The RAM size installed into the printer is displayed. Check that the RAM size is correct. RAM CHECK START RAM SIZE = 64MB Press the Go button to implement the TRAY1 CHECK.
  • Page 133 CHAPTER 5 CONTROL PANEL OPERATION Press the Go button to implement the COMPACT FLASH - R/W TEST. The reading/writing test of the compact flash card is implemented. Check that no error occurs. CARD R/W START CARD R/W OK CARD R/W OK: The compact flash card works correctly. CARD R/W ERROR: The compact flash card has a problem.

  • Page 134: Dram Test Mode

    HL-3450CN SERVICE MANUAL DRAM Test Mode This mode tests DIMMs installed on the main (video controller) PCB. <Procedure> 1) To start the test program: While holding down the Go button and + button, turn on the power. “DRAM CHECK START” will be displayed. Press the Job Cancel button to start the DRAM check.

  • Page 135: Test Print Mode

    CHAPTER 5 CONTROL PANEL OPERATION Test Print Mode This mode prints the specified pattern in order to check the engine. <Procedure> 1) Press the -, + Set buttons in this order while holding down the Go button to enter the test print mode.

  • Page 136: Engine Controller Mode

    HL-3450CN SERVICE MANUAL ENGINE CONTROLLER MODE This section describes the operation and setting procedures for each engine test in the Engine Controller Mode. In order to go into the Engine Controller Mode, turn on the printer while holding down the Secure Print, Back, Set buttons.
  • Page 137 CHAPTER 5 CONTROL PANEL OPERATION Table 5-2 Normal Mode READY Power LED OFF Ready LED ON WAIT Power LED BLINKING PRINT Power LED OFF CHK MEDIA TYPE Power LED ON CHK MEDIA FOR DUPLEX NO MEDIA CHK OUTER SELECTION NO TRAY STACKER FULL REPLACE TONER CHECK FUSER OIL...

  • Page 138: Operation Of Normal Mode

    HL-3450CN SERVICE MANUAL Operation of Normal Mode Normal Mode displays on the control panel the operational status of the printer when in the “ONLINE” state and the necessary information for the operator to implement ordinary maintenance work. Operation Procedures (1) Press the power button to turn on the printer while holding down the Secure Print, Back and Set buttons.
  • Page 139 CHAPTER 5 CONTROL PANEL OPERATION Code No. LCD Message Description of Message The Power LED is lit. The engine has completed the 00 READY [*1] warming-up process and is now ready ][*4] to print. [*1]: Applicable paper feeder is indicated as follows;...
  • Page 140 HL-3450CN SERVICE MANUAL Code No. LCD Message Description of Message The engine is idling. 11-1 CHECK MEDIA The Power LED is lit. [*1]: Applicable paper feeder is indicated as follows; 11 CHK MEDIA [*1] TYPE [*4] /UPP: Upper cassette /LF1: Lower cassette (1)
  • Page 141 CHAPTER 5 CONTROL PANEL OPERATION Code No. LCD Message Description of Message The engine is ready to print. 12-2 STACKER FULL The Power LED is lit. Remove the paper on the stacker (paper exit tray), then press the - 12 STACKER FULL button.
  • Page 142 HL-3450CN SERVICE MANUAL Code No. LCD Message Description of Message The engine is idling. MISPRINT The Power LED is lit. [*6] The type of misprint error is indicated as follows; 15 MISPRINT [*6][*4] NOPQR: No PRREQ-N signal is available. PAPER:...
  • Page 143 CHAPTER 5 CONTROL PANEL OPERATION Code No. LCD Message Description of Message The engine is stopped. 16-4 ALIGN BELT CG The Power LED is lit. The OPC belt cartridge is not installed. Reconfirm the installation 16 ALIGN BELT CG status of the OPC belt cartridge. [*4] This message will be automatically cleared by opening &...
  • Page 144 HL-3450CN SERVICE MANUAL Code No. LCD Message Description of Message The engine is idling. SLEEP MODE The Power LED is lit. This mode is cleared by sending a WAKE-UP command (EC24) from the 19 SLEEP MODE video controller. [*4] The printer is ready to print after the warming-up process of the engine.

  • Page 145: Service Mode

    CHAPTER 5 CONTROL PANEL OPERATION Service Mode Service Mode is a unique mode for the maintenance of the printer only, without the video controller card. In this mode, you can check the operation status of the printer engine Off-line and also carry out maintenance work for each of the printer components. Procedure (1) Hold down the Secure Print, Back and Set buttons and turn the printer Power (2) Using the -, Reprint, Back and Set buttons, select the mode necessary for the...
  • Page 146 HL-3450CN SERVICE MANUAL GRID PRINT A single color or two color (R,G,B) Grid Pattern and a full color Stripe Pattern can be printed as Test Prints. Procedure Description of Procedures LCD Message 1) Press the Reprint button. SERVICE MODE TEST PRINT 2) Using the Back or Set button, select the desired pattern (ex.
  • Page 147 CHAPTER 5 CONTROL PANEL OPERATION NEXT CARE INFORMATION Information relating to the replacement timing of periodical replacement parts can be obtained. This is the life for each of the components in images or pages. Procedure Description of Procedures LCD Message 1) Press the Reprint button after selecting SERVICE MODE Screen (a) “NEXT CARE INFO”.
  • Page 148 HL-3450CN SERVICE MANUAL CASSETTE TYPE The type of paper feeding cassette can be selected. Procedure Description of Procedures LCD Message 1) Press the Reprint button after selecting SERVICE MODE Screen (a) “CASSETTE TYPE”. CASSETTE TYPE 2) Using the Back or Set button, select the...
  • Page 149 CHAPTER 5 CONTROL PANEL OPERATION TOTAL PAGE The total number of printouts can be confirmed. Procedure Description of Procedures LCD Message 1) Press the Reprint button after selecting SERVICE MODE Screen (a) “TOTAL PAGE” mode. TOTAL PAGE 2) Select one type of page from among TOTAL SERVICE MODE PAGE, LFU PAGE and DPL PAGE.
  • Page 150 HL-3450CN SERVICE MANUAL EACH IMAGE Number of created images for each color used in printing can be confirmed. Procedure Description of Procedures LCD Message 1) Press the Reprint button after selecting SERVICE MODE Screen (a) “EACH IMAGE” mode. EACH IMAGE...
  • Page 151 CHAPTER 5 CONTROL PANEL OPERATION CLEAR CARE Care Code counters displayed on the LCD can be cleared. Make sure that you clear the relevant CLEAR CARE mode whenever replacing periodical replacement parts with new ones. This mode should only be used to reset the counters after replacement of faulty consumables before their life expectancy is reached.
  • Page 152 HL-3450CN SERVICE MANUAL MEDIA MANAGE The signal from the OHP sensor can be ignored when the media is selected to OHP. However, this mode should not be used under normal circumstances. Procedure Description of Procedures LCD Message 1) Press the Reprint button after selecting SERVICE MODE Screen (a) “MEDIA MANAGE”.
  • Page 153 CHAPTER 5 CONTROL PANEL OPERATION FACTORY MODE This mode consists of 9 (nine) modes for the confirmation of operation and the resetting functions necessary for maintenance work. CAUTION Before using this mode, ensure that you have the information available to reset the Page and Image counters to the correct values.
  • Page 154 HL-3450CN SERVICE MANUAL DP CHECK Each individual color Toner cartridge can be driven. Procedure Description of Procedures LCD Message 1) Press the Reprint button after selecting 39 FACTORY MODE Screen (a) “DP CHECK”. DP CHECK 2) Using the Back or Set button, select the...
  • Page 155 CHAPTER 5 CONTROL PANEL OPERATION BD CHECK Laser beam position and laser power can be checked. Procedure Description of Procedures LCD Message 1) Press the Reprint button after selecting screen (a) “BD CHECK”. 39 FACTORY MODE BD CHECK 2) The scanner motor scans the laser beam as it is rotating.
  • Page 156 HL-3450CN SERVICE MANUAL MARGIN ADJUST The position of the top margin and left margin can be confirmed and adjusted within the range -3.5mm max. and +3.5mm max. NOTE: It is recommended to use the default value in normal use. Do not perform this mode frequently.
  • Page 157 CHAPTER 5 CONTROL PANEL OPERATION LIFE PERIOD Replacement life of the periodical replacement parts can be set. NOTE: It is recommended to use the default value in normal use. Do not adjust these settings without authorization. Procedure Description of Procedures LCD Message 1) Press the Reprint button after selecting 39 FACTORY MODE...
  • Page 158 HL-3450CN SERVICE MANUAL NVRAM TUNE UP This mode is not used in normal operations, but is used when fine adjustment of the HVPSU voltage values is required. Do not use this mode unless you are sure that you understand the effects of making adjustments to the various charge voltages in the HVPSU.
  • Page 159 CHAPTER 5 CONTROL PANEL OPERATION 45-1 LP TUNE UP This mode should be used when optical density, line thickness and/or color reproduction needs to be adjusted. The adjustment is made by changing the laser power against the reference value 0 (zero) in the range -4 to +4. NOTE: Do not perform this mode frequently.
  • Page 160 HL-3450CN SERVICE MANUAL 45-2 THV TUNE UP This mode shall be used when the transfer voltage needs to be adjusted due to errors such as transfer failure onto the media. The adjustment is used to change the transfer voltage, subject to the media to be used, against the reference value 0 (zero) in the range -4 to +4.
  • Page 161 CHAPTER 5 CONTROL PANEL OPERATION 45-3 DBV TUNE UP This mode shall be used when the image optical density needs to be adjusted. Adjustment of the developer bias voltage against the reference value 0 (zero) in the range -4 and +4. NOTE: Do not perform this mode frequently.
  • Page 162 HL-3450CN SERVICE MANUAL 45-4 CBV TUNE UP This mode should be used when image defects attributed to the OPC belt need to be improved. Adjustment is to alter the OPC belt bias voltage against the reference value 0 (zero) in the range -4 to +4.
  • Page 163 CHAPTER 5 CONTROL PANEL OPERATION 45-5 FBV TUNE UP This mode should be used when image defects attributed to the transfer drum need to be improved. Adjustment is to adjust the drum cleaner bias voltage against the reference value 0 (zero) in the range -4 and +4. NOTE: Do not perform this mode frequently.
  • Page 164 HL-3450CN SERVICE MANUAL 45-6 ADC TUNE UP This mode should be used to improve the problem when there is insufficient separation of paper from the transfer drum (when the winding jam occurred around the drum). Using the mode, you can adjust the bias voltage of paper discharging output from the high-voltage power supply unit.
  • Page 165 CHAPTER 5 CONTROL PANEL OPERATION NVRAM INITIAL This mode can initialize (data clear) all the data in the NVRAM on the MCTL PWB. CAUTION BEFORE USING THIS MODE, THE VALUES FROM ‘34 TOTAL PAGES’ AND ‘35 EACH IMAGE’ MUST BE READ TO ENABLE THE CORRECT VALUES TO BE RESET USING FUNCTIONS 47 AND 48.
  • Page 166 HL-3450CN SERVICE MANUAL TOTAL PAGE SET This mode can reset the number of total pages in the NVRAM whenever NVRAM INITIAL has been executed or the MCTL PWB is replaced. NOTE: Do not perform this mode other than when replacing the MCTL PWB.
  • Page 167 CHAPTER 5 CONTROL PANEL OPERATION EACH IMAGE SET This mode can reset the number of total pages of each color in the NVRAM whenever NVRAM INITIAL is executed or the MCTL PWB is replaced. NOTE: Do not perform this mode other than when replacing the MCTL PWB. Description of Procedures LCD Message 1) Press the Reprint button after selecting...
  • Page 168 HL-3450CN SERVICE MANUAL NEXT LIFE SET This mode can set the replacement timing (number of prints) of periodic replacement parts. NOTE: Do not perform this mode other than when replacing the MCTL PWB. Description of Procedures LCD Message 1) Press the Reprint button after selecting 39 FACTORY MODE Screen (a) “NEXT LIFE SET”.

  • Page 169: Adjustment Work Procedures

    CHAPTER 5 CONTROL PANEL OPERATION Adjustment Work Procedures 3.4.1 Adjustment of top and left margin The top and left margins can be adjusted by button operation on the control panel. <Purpose> If there is no top margin or left margin set for the print guarantee area or when the MCTL PWB is replaced, the adjustment of top and left margin will be required.
  • Page 170 HL-3450CN SERVICE MANUAL 3.4.2 Setting of engine NVRAM data As data in the NVRAM has been preset to the optimum value at the factory, it is not necessary to change the preset values under normal conditions. However, fine adjustment may be required subject to the media or operational conditions.
  • Page 171 CHAPTER 5 CONTROL PANEL OPERATION 3.4.3 Confirmation and setting of total number of printouts The total number of printouts is stored in the RAM. Confirmation and setting of total number of printouts can be carried out on the control panel. <Purpose>...
  • Page 172 HL-3450CN SERVICE MANUAL 3.4.5 Initial setting of engine NVRAM Implement the initial setting at the replacement of MCTL PWB after clearing the contents of NVRAM. <Purpose> The number of images for each color will be reset when changing the MCTL PWB or executing NVRAM INITIAL.
  • Page 173 HL-3450CN SERVICE MANUAL CHAPTER 6 PERIODIC MAINTENANCE...
  • Page 174 CHAPTER 6 PERIODIC MAINTENANCE CONTENTS CHAPTER 6 PERIODIC MAINTENANCE ........... 6-3 1. GENERAL......................6-3 1.1 Handling Precautions ......................... 6-3 1.2 List of Maintenance Tools......................6-4 1.3 List of Consumables for Maintenance ..................6-5 2. PERIODIC MAINTENANCE CLEANING ............6-6 2.1 Cleaning the Register Roller....................... 6-9 2.2 Cleaning the Paper Guide ......................

  • Page 175: Chapter 6 Periodic Maintenance

    HL-3450CN SERVICE MANUAL CHAPTER 6 PERIODIC MAINTENANCE GENERAL Handling Precautions Since this high quality laser printer is a precision equipment, daily checking and periodic maintenance is indispensable to maintain the expected high performance. The following is the list of important precautions & action items for maintenance and periodic...

  • Page 176: List Of Maintenance Tools

    CHAPTER 6 PERIODIC MAINTENANCE List of Maintenance Tools Table 6-1 below lists the maintenance tools required for the printer. Table 6-1 Tool Name Function Phillips Screwdriver #1 For M3 Phillips Screwdriver #2 For M4 Phillips Screwdriver (short shank) #2 For M4 Slotted Screwdriver #1 For slotted head screw Slotted Screwdriver #2...

  • Page 177: List Of Consumables For Maintenance

    HL-3450CN SERVICE MANUAL List of Consumables for Maintenance Table 6-2 below lists the consumables for maintenance. Table 6-2 Tool Name Quantity Function Toner Cartridge (Y) 1 piece Test Print Toner Cartridge (M) 1 piece Test Print Toner Cartridge (C) 1 piece...

  • Page 178: Periodic Maintenance Cleaning

    CHAPTER 6 PERIODIC MAINTENANCE PERIODIC MAINTENANCE CLEANING See Table 6-3 for details of periodic maintenance cleaning for the following parts. (1) Register Roller (2) Paper Guide (3) Paper Exit Roller (4) Transfer Roller (5) Paper Discharger (6) OPC Belt Cartridge (7) Transfer Drum (8) Dustproof Glass of the Laser Unit (9) Printer Interior...
  • Page 179 HL-3450CN SERVICE MANUAL Periodic Maintenance Cleaning Work Table 6-3 Parts Name Cleaning Work Cleaning Cycle *1 Description Section (Condition or Case) 1. Open the transfer unit. Defective image Register Roller 2. Clean roller and surrounding area using a Smeared paper dry cloth.
  • Page 180 CHAPTER 6 PERIODIC MAINTENANCE Periodic Maintenance Cleaning Work Table 6-3 Parts Name Cleaning Work Cleaning Cycle *1 Description Section (Condition or Case) 1. Remove the transfer drum. Defective image Transfer Drum 2. Clean the dirt from the transfer drum Periodic maintenance surface using a cloth.

  • Page 181: Cleaning The Register Roller

    HL-3450CN SERVICE MANUAL Cleaning the Register Roller The register roller should be cleaned according to the periodic maintenance cleaning cycle set out in Table 6-3. Tools to Prepare Cotton cloth (2 3 pieces) Cleaning Procedure (1) Turn off the power supply, and unplug the power cable.

  • Page 182: Cleaning The Paper Guide

    CHAPTER 6 PERIODIC MAINTENANCE Cleaning the Paper Guide The paper guide should be cleaned according to the periodic maintenance cleaning cycle set out in Table 6-3. Tools to Prepare Cotton cloth (2 3 pieces) Cleaning Procedure (1) Remove the media cassette from the printer. (2) Remove paper in the media cassette.

  • Page 183: Cleaning The Paper Exit Roller

    HL-3450CN SERVICE MANUAL Cleaning the Paper Exit Roller The paper exit roller should be cleaned according to the periodic maintenance cleaning cycle set out in Table 6-3. Tools to Prepare Cotton cloth (2 3 pieces) Cleaning Procedure (1) Turn off the power supply, and unplug the power cable.

  • Page 184: Cleaning The Transfer Roller

    CHAPTER 6 PERIODIC MAINTENANCE Cleaning the Transfer Roller The transfer roller should be cleaned according to the periodic maintenance cleaning cycle set out in Table 6-3. Tools to Prepare Cotton cloth (2 3 pieces) Cleaning Procedure (1) Turn off the power supply, and unplug the power cable. (2) Open the rear access cover (transfer unit).

  • Page 185: Cleaning The Paper Discharger

    HL-3450CN SERVICE MANUAL Cleaning the Paper Discharger The paper discharger should be cleaned according to the periodic maintenance cleaning cycle set out in Table 6-3. Tools to Prepare Cotton cloth (2 3 pieces) Cotton swab (2 3 pieces) Cleaning Procedure (1) Turn off the power supply, and unplug the power cable.

  • Page 186: Cleaning The Opc Belt Cartridge

    CHAPTER 6 PERIODIC MAINTENANCE Cleaning the OPC Belt Cartridge The OPC belt cartridge should be cleaned according to the periodic maintenance cleaning cycle set out in Table 6-3. PRECAUTION Do not directly touch the OPC belt surface with bare hands or gloves. If the belt is exposed for more than two minutes to a light source of 800 lux, the belt may be damaged.

  • Page 187: Cleaning The Transfer Drum

    HL-3450CN SERVICE MANUAL Cleaning the Transfer Drum The transfer drum should be cleaned according to the periodic maintenance cleaning cycle set out in Table 6-3. Tools to Prepare Cotton cloth (2 3 pieces) Cleaning Procedure (1) Turn off the power supply.

  • Page 188: Cleaning The Dustproof Glass In The Laser Unit

    CHAPTER 6 PERIODIC MAINTENANCE Cleaning the Dustproof Glass in the Laser Unit The dustproof glass in the laser unit should be cleaned according to the periodic maintenance cleaning cycle set out in Table 6-3. Tools to Prepare Cotton cloth (2 3 pieces) Cotton swab (2 3 pieces)

  • Page 189: Cleaning The Printer Interior

    HL-3450CN SERVICE MANUAL Cleaning the Printer Interior The printer interior (bottom) should be cleaned according to the periodic maintenance cleaning cycle set out in Table 6-3. Tools to Prepare Toner vacuum cleaner Cotton cloth (2 3 pieces) Cleaning Procedure (1) Open the top cover and the front cover.

  • Page 190: Cleaning The Oil Pad

    CHAPTER 6 PERIODIC MAINTENANCE 2.10 Cleaning the Oil Pad The oil pad should be cleaned according to the periodic maintenance cleaning cycle set out in Table 6-3. When time is due for replacement of the oil pad, the following message appears on the control panel.* REPLACE OIL PAD * The message can be turned OFF to prevent it from appearing on the control panel.

  • Page 191: Periodic Maintenance Parts

    HL-3450CN SERVICE MANUAL PERIODIC MAINTENANCE PARTS Maintenance Work should be implemented according to the “Periodic Maintenance Parts and Maintenance Cycle” set out in Table 6-4. Table 6-4: Periodic Maintenance Parts and Maintenance Cycle Maintenance Parts Description Replacement Cycle *1 Parts Name...
  • Page 192 CHAPTER 6 PERIODIC MAINTENANCE These figures are based on an average of 5% coverage of the printable area for one color using A4/Letter-size laser paper. The frequency of replacement will vary, depending on the complexity of the prints, the percentage of coverage, the size of paper, pages/job, and the type of media.

  • Page 193: Periodic Maintenance Procedures

    HL-3450CN SERVICE MANUAL PERIODIC MAINTENANCE PROCEDURES The printer displays messages on the control panel screen to indicate replacement is due for most of the periodic maintenance parts in both the Video Controller Mode and the Engine Controller Mode. However, the procedure to clear the message differs between the two modes. The following sections describe the Video Controller Mode messages only and should be used when replacing parts that have reached their life.
  • Page 194 CHAPTER 6 PERIODIC MAINTENANCE (3) Release the belt cartridge lock levers at both sides (left & right). (Fig.6-11) (4) Pull out the OPC belt cartridge. Belt cartridge lock lever (Left) Belt cartridge lock lever (Right) Fig. 6-12 (5) Prepare a new belt cartridge. Tension release pins (6) Remove the protective sheet from a new OPC belt cartridge, and then pull...

  • Page 195: Fusing Unit Replacement

    HL-3450CN SERVICE MANUAL Fusing Unit Replacement Criterion of Replacement The fusing unit should be replaced with a new one according to the periodical maintenance cycle set out in Table 6-4. When the time is due for replacement of the fusing unit, the following message appears on the control panel.
  • Page 196 CHAPTER 6 PERIODIC MAINTENANCE CAUTION When removing the fusing unit, take care to keep the unit level so that no oil leakage or spillage occurs. When shipping the printer, remove the oil bottle and the fuser cleaner from the fusing unit. After removing the oil bottle, be sure to remove the oil remaining in the fusing unit with the supplied syringe.
  • Page 197 HL-3450CN SERVICE MANUAL (2) Plug the power cable into the power outlet and turn on the printer. (3) Upon completion of the warming-up process. (4) Press any of the Menu buttons (+, -, Set or Back) to take the printer Off Line.

  • Page 198: Transfer Roller Replacement

    CHAPTER 6 PERIODIC MAINTENANCE Transfer Roller Replacement Criterion of Replacement The transfer roller should be replaced at the same time as a new discharger according to the periodical maintenance cycle set out in Table 6-4. When time is due for replacement of the transfer roller, the following message appears on the control panel.
  • Page 199 HL-3450CN SERVICE MANUAL (2) Pull up the transfer roller to remove it. (Fig.6-20) (3) Install a new transfer roller into the printer. (4) Fix the transfer roller with the lock levers. Transfer roller Fig. 6-21 Sequence of Assembling (1) Close the rear access cover.

  • Page 200: Paper Discharger Replacement

    CHAPTER 6 PERIODIC MAINTENANCE Paper Discharger Replacement Criterion of Replacement The paper discharger should be replaced with a new discharger at the same time as the transfer roller according to the periodical maintenance cycle set out in Table 6-4. When time is due for replacement of paper discharger, the following message appears on the control panel.
  • Page 201 HL-3450CN SERVICE MANUAL Sequence of Replacement (1) Pull the right hand side of the paper discharger slightly, then lift it out of the transfer unit to remove the paper discharger. (Fig.6-22) Paper discharger Fig. 6-23 (2) Clean the area where the paper discharger is mounted.

  • Page 202: Drum Cleaner Replacement

    CHAPTER 6 PERIODIC MAINTENANCE Drum Cleaner Replacement Criterion of Replacement The drum cleaner should be replaced with a new one according to the periodical maintenance cycle set out in Table 6-4. When time is due for replacement of the drum cleaner, the following message appears on the control panel.
  • Page 203 HL-3450CN SERVICE MANUAL Drum cleaner (2) Holding the handle located on the top of the drum cleaner, push it backwards. (3) Remove the drum cleaner by lifting it out. (Fig.6-25) Fig. 6-26 (4) Clean the area where the drum cleaner is mounted.

  • Page 204: Ozone Filter Replacement

    CHAPTER 6 PERIODIC MAINTENANCE Ozone Filter Replacement Criterion of Replacement Although the maintenance message indicating ozone filter replacement is not displayed on the LCD, the ozone filter should be replaced with a new one according to the periodical maintenance cycle set out in Table 6-4. This is to prevent ozone from being exhausted due to the deterioration of the ozone filter.

  • Page 205: Paper Feeding Roller And Separator Pad Replacement

    HL-3450CN SERVICE MANUAL Paper Feeding Roller and Separator Pad Replacement Criterion of Replacement The paper feeding roller and separator pad should be replaced with new ones according to the periodical maintenance cycle set out in Table 6-4. When time is due for replacement of the paper feeding roller and separator pad, the following message appears on the control panel.

  • Page 206: Transfer Drum Replacement

    CHAPTER 6 PERIODIC MAINTENANCE Transfer Drum Replacement Criterion of Replacement The transfer drum should be replaced with a new one according to the periodical maintenance cycle set out in the Table 6-4. When time is due for replacement of the transfer drum, the following message appears on the control panel.

  • Page 207: Oil Pad Replacement

    HL-3450CN SERVICE MANUAL Oil Pad Replacement Criterion of Replacement The oil pad should be replaced with a new one according to the periodical maintenance cycle set out in the Table 6-4. When time is due for replacement of the oil pad, the following message appears on the control panel.*...
  • Page 208 CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY...
  • Page 209 CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY CONTENTS CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY........ 7-4 1. BEFORE STARTING DISASSEMBLY.............. 7-4 1.1 Precautions ..........................7-4 1.2 Preparation of Disassembly ..................... 7-4 2 PARTS NAME....................7-6 2.1 Cover ............................7-6 2.2 Circuit Boards (PWBs) ......................7-7 2.3 Motor Units..........................
  • Page 210 HL-3450CN SERVICE MANUAL 4.3 Left Side of the Printer ......................7-32 4.3.1 Video Controller PCB ...................... 7-32 4.3.2 MCTL PWB ........................7-34 4.3.3 High-voltage power supply unit (High voltage unit 3) ............7-35 4.3.4 Interlock switch (Rear) ....................7-36 4.3.5 Drum encoder sensor (PS4) ................... 7-37 4.3.6 Fuser connector 3 ......................

  • Page 211: Chapter 7 Disassembly & Re-Assembly

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY BEFORE STARTING DISASSEMBLY Precautions Follow the precautions described below during maintenance work. (1) Do not implement any operation, disassembly or modification which is not set out in this manual. (2) This printer incorporates dangerous parts subject to warnings such as “High Temperature”, “High Voltage”...
  • Page 212 HL-3450CN SERVICE MANUAL Table 7-1: Table of Screw Sizes Used in the Printer Size and Shape of Screw Class Code Name of Screw Remarks M-Thread Length Sharp BT3x8 BT3x12 10mm Cross head tapping Used for screw plastic parts. BT4x8 BT4x10...

  • Page 213: Parts Name

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY PARTS NAME Cover Front View Upper cover 4.2.5 Control panel Top cover (Paper exit unit cover) 4.4.2 Side cover (LF) 4.2.6 Power button Side cover (R) 4.1.1 Front outer cover Base cover (R) 4.5.1 4.1.2 Media cassette Fig.

  • Page 214: Circuit Boards (Pwbs)

    HL-3450CN SERVICE MANUAL Circuit Boards (PWBs) Erase lamp 4.2.11 IOD2 PWB Panel PWB 4.1.5 4.2.2 High-voltage power IOD1 PWB supply PCB 4.2.7 4.3.3 MCTL PWB Video controller 4.3.2 4.3.1 Low-voltage power supply 4.3.8 Fig. 7-3 Motor Units Ozone fan (Cooling fan (OZ)) 4.1.9...

  • Page 215: Clutches

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY Clutches Cleaner cam clutch Fuser clutch 4.1.8 Cleaner clutch TR cam clutch 4.1.7 Registration clutch 4.1.6 Paper feeding clutch 4.1.12 Developer clutch (K) Developer clutch (Y) 4.1.15 Developer clutch (M) Developer clutch (C) Fig. 7-5 Sensors Temperature sensor (TH) (Thermistor)

  • Page 216: Disassembly Flow

    3. DISASSEMBLY FLOW 4.PAPER EXIT 6.REAR (Transfer Unit) UNIT 4.6.1 1. RIGHT SIDE 4.4.1 Rear Cover (U) Rear Access Cover 2.TOP 3.LEFT SIDE 4.1.1 4.2.2 Panel PWB Side Cover (R) Upper Side 4.2.1 Transfer Unit Video Controller PCB (LCD inclusive) Cover (LU) 4.3.1 4.4.2...

  • Page 217: Disassembly Procedure

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY DISASSEMBLY PROCEDURE Right Side of the Printer 4.1.1 Side cover 3 (R) (1) Remove the set screw BT4x10 (1 pc.) of side cover 3 (R) at the rear of the printer. Side cover 3 (R) Fig.

  • Page 218: Base Cover 3 (R)

    HL-3450CN SERVICE MANUAL 4.1.2 Base cover 3 (R) (1) Remove the set screws BT4x10 (2 pcs.) from the base cover 3 (R). (2) Remove the base cover 3 (R) from the base. Base cover 3 (R) Fig. 7-9 PRECAUTION When assembling the base cover, insert the leading edge of the base cover 3 (R) into the two hooks provided at the bottom (left and right) of the base plate.

  • Page 219: Main Motor 3 (Mm)

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.1.3 Main motor 3 (MM) CAUTION Take care not to stress the motor drive PCB when removing the connector or handling the motor / PCB assembly. (1) Disconnect the cable (1 pc.) from the main motor 3 PCB. (2) Remove the tapping screws ST3x6 (4 pcs.) holding the main motor assembly.

  • Page 220: Developer Drive Motor 3 (Dm)

    HL-3450CN SERVICE MANUAL 4.1.4 Developer drive motor 3 (DM) CAUTION Take care not to stress the motor drive PCB when removing the connector or handling the motor / PCB assembly. (1) Disconnect the connector (1 pc.) from the developer drive motor PCB.

  • Page 221: Iod2 Pwb

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.1.5 IOD2 PWB (1) Disconnect all the harness connectors (15 pcs.) connected to the IOD2 PWB. (2) Remove the fixing screw ST3x6 (1 pc.) from the IOD2 PWB. (3) Remove the IOD2 PWB from the main frame. PRECAUTION When handling the IOD2 PWB take care not to cause electrostatic damage to the PWB.

  • Page 222: Registration Clutch

    HL-3450CN SERVICE MANUAL 4.1.6 Registration clutch (1) Remove the outer plastic C ring from the shaft. (2) Pull out the registration clutch from the shaft. Registration clutch C ring Fig. 7-14 4.1.7 TR cam clutch 3 (1) Remove the outer plastic C ring from the shaft.

  • Page 223: Cleaner Clutch 3 / Cleaner Cam Clutch 3 / Fuser Clutch 3

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.1.8 Cleaner clutch 3 / Cleaner cam clutch 3 / Fuser clutch 3 (1) Remove the outer plastic C ring from the shaft of each of the clutches. (2) Pull out the cleaner clutch 3, Cleaner cam clutch 3 and fuser clutch 3 from their shafts at the same time.

  • Page 224: Ozone Fan (Ozfan) (Cooling Fan (Oz))

    HL-3450CN SERVICE MANUAL 4.1.9 Ozone fan (OZFAN) (Cooling fan (OZ)) (1) Remove the screws ST3x6 (3 pcs.) and BT4x8 (1 pc.) to remove the stay (R). (2) Remove the set screw ST3x6 (1 pc.) to remove the ozone fan case with the duct from the main frame.

  • Page 225: Bd3 Gear Assembly

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.1.10 BD3 gear assembly (1) Remove the screws ST3x6 (3 pcs.) from the BD3 gear assembly. (2) Remove the BD3 gear assembly from the frame. NOTE: Be sure to remove the set screws BT4x10 (2 pcs.) from the upper cover before removing the screws ST3x6 (3 pcs.) from the BD3 gear assembly.

  • Page 226: Paper Feeding Clutch / Ep3 Gear Assembly

    HL-3450CN SERVICE MANUAL 4.1.12 Paper feeding clutch / EP3 gear assembly (1) Remove the set screw ST3x6 (1 pc.) to remove the metal retainer. (2) Remove the outer plastic C ring from the shaft. (3) Remove the paper feeding clutch from the shaft.

  • Page 227: Developer Drive Unit 3

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.1.14 Developer drive unit 3 (1) Remove the set screw ST3x6 (1pc.) to remove the cover RF. (2) Release the harnesses from the harness holder. (3) Remove the developer drive gear for each color toner from the inside of the developer driver unit 3.

  • Page 228: Developer Clutch 3 (K, Y, M, C)

    HL-3450CN SERVICE MANUAL 4.1.15 Developer clutch 3 (K, Y, M, C) (1) Remove the inner E ring and washer of each developer clutch 3 from the shaft. (2) Pull out the developer clutch 3 and shaft from the bearing. NOTE: One gear is included with each replacement developer clutch 3.

  • Page 229: Waste Toner Feeder (L)

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.1.17 Waste toner feeder (L) NOTE: The waste toner feeder (L) is composed of the plastic tube and auger spring gear unit. (1) Remove the screw ST3x6 (1 pc.) holding the metal plate of the waste toner feeder. (2) Pull out the waste toner feeder (L) from the main frame.

  • Page 230: Top Of The Printer

    HL-3450CN SERVICE MANUAL Top of the Printer 4.2.1 Upper side cover (LU) (Upper side cover 3 (L)) (1) Open the top cover. (2) Remove the set screw BT4x10 securing the upper side cover (LU). (3) Press the exterior of the side cover 3 inwards and unlock the hooks (three locations) from the upper side cover (LU).

  • Page 231: Panel Pwb (Including Lcd)

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.2.2 Panel PWB (including LCD) (1) Remove the shoulder screw SP4x9* (1 pc.) from the panel case assembly and disconnect the connector. (2) Remove the set screws BT3x8 (4 pcs.) from the panel PWB and remove the panel shield plate, PWB, LCD and panel button from the panel case assembly.

  • Page 232: Base Cover 3 (L)

    HL-3450CN SERVICE MANUAL 4.2.4 Base cover 3 (L) (1) Remove the set screws BT4x10 (2 pcs.) from the base cover 3 (L). (2) Remove the base cover 3 (L) from the base by releasing it from the front of the printer first.

  • Page 233: Upper Cover (Top Cover 3)

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.2.5 Upper cover (Top cover 3) (1) Open the front cover and release the belt cartridge lock levers. (2) Remove the side cover 3 (R). (Refer to subsection 4.1.1 in this chapter.) (3) Remove the set screws BT4x10 (2 pcs.) securing the upper cover. (Top x 1 and Right hand side x 1) (4) Slightly lift up the rear edge of the upper cover.

  • Page 234: Iod1 Pwb

    HL-3450CN SERVICE MANUAL 4.2.7 IOD1 PWB (1) Remove the set screws ST3x6 (4 pcs.) from the shield (upper). (2) Disconnect all the harness connectors (16 pcs.) connected to the IOD1 PWB. Note that the DCN3 connector is a link plug and need not be removed unless necessary. (Refer to the figure below.)
  • Page 235 CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY (3) Remove the fan motor and interlock switch from the fan case after releasing the fan cover plastic clips. Control fan case Fan motor Control fan case Fig. 7-37 (4) Remove the interlock switch and operating arm from the case. CAUTION Since the interlock switch is an important safety item, after installation confirm that the switch operates correctly.

  • Page 236: Belt Sensor (Pbs)

    HL-3450CN SERVICE MANUAL 4.2.9 Belt sensor (PBS) (1) Remove the set screws ST3x6 (1 pc.) to remove the belt sensor base from the main frame. (2) Disconnect the connector (1 pc.) to the belt sensor. (3) Release the catches to remove the belt sensor from the base.

  • Page 237: Erase Lamp 3 / Erase Holder

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY NOTE: For easier removal, push the drum upwards and diagonally forwards. When re-assembling the transfer drum 3, slide the drum shaft between the metal plates and ensure the drum is fully located into the correct retaining position. PRECAUTION Do not touch the transfer drum surface with your bare hands or scratch it.

  • Page 238: Drum Jam Sensor (Dpj)

    HL-3450CN SERVICE MANUAL 4.2.12 Drum jam sensor (DPJ) (1) Release the catches and remove the cover F. (2) Disconnect the drum jam sensor connector. (3) Remove the drum jam sensor. NOTE: The dram jam sensor (DPJ ) is identical to the belt sensor (PBS).

  • Page 239: Left Side Of The Printer

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY Left Side of the Printer 4.3.1 Video Controller PCB CAUTION Turn off the printer power switch and unplug the power cable from the outlet. Remove the interface cable connector. (1) Remove the two screws to remove the main controller board from the printer. Main controller board Fig.
  • Page 240 HL-3450CN SERVICE MANUAL (3) Remove the DIMM. (4) Remove the screw at the center of the main PCB base plate. (5) Remove the CPU heatspred. (6) Remove the sheet (GP1-2.0-025025Y). (7) Remove the two screws on the CDCC IF. (8) Remove the two screws to remove the main PCB base plate.

  • Page 241: Mctl Pwb

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.3.2 MCTL PWB CAUTION Remove the Main (Video Controller) PWB before starting this disassembly. (1) Remove the set screw ST3x6 (1 pc.) from shield cover ‘B’. Slide the cover upwards and remove it. (2) Disconnect all the harness connectors (7 pcs.) connected to the MCTL PWB. (3) Remove the set screws ST3x6 (4 pcs.) from the MCTL PWB.

  • Page 242: High-Voltage Power Supply Unit (High Voltage Unit 3)

    HL-3450CN SERVICE MANUAL 4.3.3 High-voltage power supply unit (High voltage unit 3) (1) Remove the set screws ST3x6 (2 pcs.) to remove the shield cover ‘A’. (2) Remove the set screws ST3x6 (4 pcs.) to remove the shield case ‘A’ assembly.

  • Page 243: Interlock Switch (Rear)

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY CAUTION When disconnecting the connector from the CBV terminal, push both sides of the connector. Pulling it hard may cause connector damage. WARNING The high voltage power supply unit generates high voltages of up to 5KV. You can get an electric shock if you touch the unit while it is powered on.

  • Page 244: Drum Encoder Sensor (Ps4)

    HL-3450CN SERVICE MANUAL 4.3.5 Drum encoder sensor (PS4) (1) Remove the sensor case assembly from the frame (L) by releasing the two catches. (2) Disconnect the connector (1 pc.) to the encoder sensor. (3) Remove the drum encoder sensor from the sensor case.

  • Page 245: Rear Cover 3 (R)

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.3.7 Rear cover 3 (R) (1) Remove the set screw BT4x10 (1 pc.) of rear cover 3 (R). (2) Remove the rear cover 3 (R). Rear cover 3 (R) Fig. 7-54 4.3.8 Low-voltage power supply unit (Power supply unit 3 (EC)(US)) (1) Remove the power switch key by pulling it forwards.
  • Page 246 HL-3450CN SERVICE MANUAL (4) Remove the set screw ST3x6 (2 pcs.) holding the power inlet base. (5) Remove the set screw M4x6 complete with the shakeproof washer to release the ground wire. Power inlet base Ground wire Fig. 7-56 (6) Disconnect the connectors (4 pcs.) from the low-voltage power supply PCB.

  • Page 247: Interlock Switch (Front) (For Front Cover)

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.3.9 Interlock switch (Front) (for front cover) (1) Remove the set screw (1 pc.) to remove the switch holder assembly from the frame. (2) Release the two hooks to remove the interlock switch. (3) Disconnect the switch connector. (4) Remove the interlock switch from the switch case.

  • Page 248: Toner Key Sensor (Tnk)

    HL-3450CN SERVICE MANUAL 4.3.10 Toner key sensor (TNK) (1) Remove the set screws ST3x6 (4 pcs.) from the toner key sensor PCB. (2) Disconnect the connector (1 pc.) connected to the IOD1 PWB. (3) Remove the toner key sensor PCB.

  • Page 249: Paper Exit Unit

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY Paper Exit Unit 4.4.1 Rear cover 3 (U) (1) Remove the rear cover 3 (R). (Refer to subsection 4.3.6 in this chapter.) (2) Release the two hooks to remove the rear cover 3 (U). (3) Remove the rear cover (U) caps (2 pcs.) from the rear cover 3 (U) if necessary. Rear cover 3 (U) Rear cover (U) cap Fig.

  • Page 250: Top Cover (Paper Exit Unit 3) / Fuser Fan (Fufan) (Cooling Fan (Ex))

    HL-3450CN SERVICE MANUAL (5) Press the top cover back plate backwards to release the fan motor assembly from the paper exit guide unit. (6) Remove the fuser fan motor and filter from the case. Filter Fan case Fuser fan motor...

  • Page 251: Cleaning Roller Sensor (Ps5)

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.4.3 Cleaning roller sensor (PS5) (1) Remove the set screw ST3x6 (1 pc.) of the sensor base holding the cleaning roller sensor. (2) Disconnect the harness connected to the cleaning roller sensor. (3) Remove the cleaning roller sensor from the sensor base. Cleaning roller sensor Sensor base Paper exit guide...

  • Page 252: Paper Exit Sensor (Ps2)

    HL-3450CN SERVICE MANUAL 4.4.5 Paper exit sensor (PS2) (1) Disconnect the harness connected to the paper exit sensor. (2) Remove the paper exit sensor from the sensor base. Paper exit sensor Sensor base Fig. 7-67 NOTE: When re-assembling the cleaning roller sensor and paper exit sensor, be sure to connect the correct harness to either sensors as below;...

  • Page 253: Paper Exit Roller 3

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.4.7 Paper exit roller 3 (1) Remove the set screw ST3x6 (1 pc.) to remove the plastic retainer from the paper exit guide. (2) Remove the C ring and washer from the left and right hand sides of the roller. (3) Remove the plastic bush at both sides.

  • Page 254: Front Of The Printer

    HL-3450CN SERVICE MANUAL Front of the Printer 4.5.1 Front outer cover (Front cover 3) (1) Open the front cover unit 3. (2) Remove the set screws BT4x10 (2 pcs.) from the front cover unit 3. (3) Unhook the five hooks and remove the front outer cover.
  • Page 255 CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY (4) Remove the screws BT4x8 (4 pcs.) from the front inner cover. (5) Unhook the two hooks by slightly lifting up the front inner cover and remove the hinge from the front cover unit 3. (6) Disconnect the connectors (4 pcs.) from the front cover unit 3.

  • Page 256: Laser Unit (Scanner Motor Inclusive) (Optical Unit 3)

    HL-3450CN SERVICE MANUAL 4.5.3 Laser unit (Scanner motor inclusive) (Optical unit 3) (1) Remove the set screws ST3x6 (2 pcs.) to remove the scanner cover. (2) Remove the fixing screws with flanges FST3x10 (3 pcs.) from the laser unit. (3) Disconnect the harness connector (1 pc.) from the laser unit.

  • Page 257: Rear Of The Printer

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY Rear of the Printer 4.6.1 Rear access cover (TR unit cover 3) / Transfer unit 3 (1) Open the rear access cover. (2) Remove the fixing screw BT4x10 (1 pc.) of the retaining strap supporting the transfer unit 3 to the printer body.

  • Page 258: Transfer Roller 3

    HL-3450CN SERVICE MANUAL 4.6.2 Transfer roller 3 (1) Lift the transfer roller 3 lock levers to release both ends of the roller. (2) Pull up and remove the transfer roller 3. Transfer roller 3 Lock lever Fig. 7-77 4.6.3 Register roller (1) Remove the roller fixing C rings from both ends of the roller.

  • Page 259: Paper Size Sensor 3 (Psu)

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.6.4 Paper size sensor 3 (PSU) (1) Remove the set screws ST3x6 (2 pcs.) to remove the lower paper guide. (2) Remove the set screws ST3x6 (2 pcs.) holding the paper size sensor PCB. (3) Disconnect the paper size sensor connector, and remove the paper size sensor. Lower paper guide Paper size sensor Fig.

  • Page 260: Paper Empty Sensor (Ps3) / Ohp Sensor 3 (Ohp)

    HL-3450CN SERVICE MANUAL (5) Pull up and remove the separator pad (2). Separator pad (2) Fig. 7-81 PRECAUTION Do not touch the surface of the paper feeding roller and separator pad (2). 4.6.6 Paper empty sensor (PS3) / OHP sensor (OHP) (1) Disconnect the sensor connectors.

  • Page 261: Paper Feeding Sensor (Ps1)

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.6.7 Paper feeding sensor (PS1) (1) Remove the paper feeding sensor from the rear frame. (2) Disconnect the connector on the paper feeding sensor. Paper feeding sensor Fig. 7-83 Fusing Unit DANGER Note in Parts Replacement The fusing unit consists of important safety parts.

  • Page 262: Oil Pan Unit 3

    HL-3450CN SERVICE MANUAL 4.7.1 Oil pan unit 3 (1) Remove the fixing screw ST3x6 (1 pc.) to remove the F cover (L). (2) Remove the fixing screw ST3x6 (1 pc.) to remove the F cover (R). (3) Remove the fixing screws ST3x6 (2 pcs.) to remove the oil pan unit 3 from the fusing unit.

  • Page 263: Fusing Heater Lamp (Fusing Heater 3 (Us)(Ec))

    CHAPTER 7 DISASSEMBLY & RE-ASSEMBLY 4.7.3 Fusing heater lamp (Fusing heater 3 (US)(EC)) (1) Remove the fixing screw ST3x6 (2 pcs.) and slide the F cover (B) to the right to remove (2) Remove the fixing screws with washer M3x6 (2 pc.) from securing the two heater harnesses.

  • Page 264: Troubleshooting

    HL-3450CN SERVICE MANUAL CHAPTER 8 TROUBLESHOOTING...
  • Page 265 CHAPTER 8 TROUBLESHOOTING CONTENTS CHAPTER 8 TROUBLESHOOTING ..........8-3 1. OUTLINE OF TROUBLESHOOTING ............8-4 2. OPERATOR CALL..................8-5 2.1 Video Controller Mode......................8-5 2.2 Engine Controller Mode......................8-8 3. PAPER TRANSPORT ERROR..............8-10 3.1 Feed Jam..........................8-10 3.2 Inner Jam..........................8-11 3.2.1 Paper guide D ..........................8-11 3.3 Outer Jam...........................8-13 3.4 Others..........................8-13 4.

  • Page 266: Chapter 8 Troubleshooting

    HL-3450CN SERVICE MANUAL CHAPTER 8 TROUBLESHOOTING This chapter contains troubleshooting information for both the Video Controller Mode and the Engine Controller Mode. If any problem occurs during the normal usage of the printer, which means the printer is being used in the Video Controller Mode, clear the problem by referring to the troubleshooting information in the following sections for the Video Controller Mode or the user’s guide.

  • Page 267: Outline Of Troubleshooting

    CHAPTER 8 TROUBLESHOOTING OUTLINE OF TROUBLESHOOTING Printer Problem Paper Transport Operator Call Service Call Image Failure Error [Section 2.1] [Section 2 & 3] [Section 5] Enter the Engine Controller Mode Turn off the power, hold down the Turn off the power Secure Print, Back and Set then turn it back on buttons and then turn the main...

  • Page 268: Operator Call

    HL-3450CN SERVICE MANUAL OPERATOR CALL Video Controller Mode The Power LED is lit and an applicable message appears on the liquid crystal display (LCD) in the following cases; 1) Consumables require to be replenished. 2) Waste toner pack is full of waste toner.
  • Page 269 Install the lower tray unit. NO TR ROLLER Install the transfer roller 2. ILLEGAL TONER Use only Brother genuine toner cartridges. NO TRAY 1/2/3 The indicated paper Tray was not detected, install it, or ensure it is inserted correctly. SIZE ERROR T1/2/3 Specify the correct paper size for the indicated tray.
  • Page 270 HL-3450CN SERVICE MANUAL Display Message Remarks DIMM ERROR Ensure that the DIMM is installed correctly. CARD REMOVAL The Flash card was removed while the printer was powered on. Power cycle the printer. BUFFER ERROR Check the cable connection between the computer and printer.

  • Page 271: Engine Controller Mode

    CHAPTER 8 TROUBLESHOOTING Engine Controller Mode The Power LED is lit, and applicable messages appear on the liquid crystal display (LCD) in the following cases; 1) Consumables require to be replenished. 2) Waste toner pack is full of waste toner. 3) Paper jam.
  • Page 272 HL-3450CN SERVICE MANUAL Display Message Meaning Countermeasure 16 ALIGN FU UNIT Fusing unit not installed Remove the fusing unit and refit it. Confirm it is correctly installed. 16 ALIGN BELT CG OPC belt cartridge not Confirm the installation of the installed OPC belt cartridge.

  • Page 273: Paper Transport Error

    CHAPTER 8 TROUBLESHOOTING PAPER TRANSPORT ERROR Paper is transported through the path shown in Fig.8-1. Paper jams at the following locations are easily cleared. Paper Feeding Roller Fusing Unit Transfer Unit Paper Exit Unit Paper exit roller OPC belt cartridge Fusing unit Oil bottle Drum cleaner Top cover...

  • Page 274: Inner Jam

    HL-3450CN SERVICE MANUAL Inner Jam Table 8-4 Problem Item Step Check Item Result Action Open the transfer unit and check. Is there any paper inside the Remove the paper inside. unit? Is the transfer roller firmly Fix the transfer roller with locked by the lock lever? the lock lever.
  • Page 275 CHAPTER 8 TROUBLESHOOTING Remove the oil sensor cover. Oil sensor cover Fig. 8-3 Pushing up the installation claw toward the engine, remove the paper guide. Paper guide Paper guide Fig. 8-4 8-12...

  • Page 276: Outer Jam

    HL-3450CN SERVICE MANUAL Install a new paper guide D (with a pawl for separating paper). Attend the orientation of installation. Install the each parts (the oil sensor cover and so on) in accordance with the reverse order of remove procedures.

  • Page 277: Service Call

    CHAPTER 8 TROUBLESHOOTING SERVICE CALL If errors or failures occurred inside the printer, the applicable error message will be displayed on the control panel, and the printer stops. If errors or failures repeat even after resetting the power button, confirm the error code and then refer to the appropriate section below. Error occurs.

  • Page 278: Video Controller Mode

    HL-3450CN SERVICE MANUAL Video Controller Mode Table 8-7 Service Call Message Meaning Countermeasure FATAL ERROR EX Update with a new Firmware. ERROR S01 SERVICE CALL ADRL ERROR EX Update with a new Firmware. ERROR S02 SERVICE CALL ADRS ERROR EX Update with a new Firmware.
  • Page 279 CHAPTER 8 TROUBLESHOOTING Service Call Message Meaning Countermeasure Replace with a new main ERROR H66 NVRAM write error (video controller) PCB. NV_W ERROR Replace with a new main ERROR H67 NVRAM read error (video controller) PCB. NV_R ERROR Replace with a new main ERROR H68 NVRAM read/ write error (video controller) PCB.
  • Page 280 HL-3450CN SERVICE MANUAL Status Display Description Developing motor error ERROR EE1 WARNING Main motor error ERROR EE2 WARNING Drum error ERROR EE3 WARNING Toner empty sensor error ERROR EE4 WARNING Transfer roller 2 solenoid error ERROR EE5 WARNING Drum cleaning solenoid error...

  • Page 281: Engine Controller Mode

    CHAPTER 8 TROUBLESHOOTING Status Display Description Fuser temperature 4 error ERROR EH4 WARNING Beam detector error ERROR EL1 WARNING Scanner motor error ERROR EL2 WARNING Laser power error ERROR ELL WARNING Duplex controller hardware error ERROR EP1 WARNING Feeder pass select solenoid error ERROR EP3 WARNING Duplex motor error...
  • Page 282 HL-3450CN SERVICE MANUAL Code Description Developing motor error Main motor error Transfer drum rotational error Toner sensor error TR cam clutch error Cleaner cam clutch error Cleaner clutch error Fuser clutch error Belt sensor error Erase lamp error Control fan error...
  • Page 283 CHAPTER 8 TROUBLESHOOTING Code Description of Error Cause of Error Clearance Method 1. Failure of MCTL PWB 1. Turn on and off the power switch. NVRAM Error 2. Above method 1 does not work, implement "C3 Error Clearance Procedure". EEPROM 3.
  • Page 284 HL-3450CN SERVICE MANUAL Description of Error Cause of Error Code Clearance Method 1. Power Feeding Failure 1. Implement the same clearance procedures employed for E2 error. Process Timing Error. 2. MM Failure [Note]: MM stands for OPC Belt Drive Main Motor.
  • Page 285 CHAPTER 8 TROUBLESHOOTING Error Code Name of Part Developer Clutch (DCLY) Confirm the connection of Connector. Is the connection proper between ECN14 of IOD2 and Clutch (DCLY) ? Connect the harness. Is the harness of Clutch (DCLY) broken ? Connect the connector properly. Is D1 Error cleared ? Complete Check the voltage at DCLY ON-N.
  • Page 286 HL-3450CN SERVICE MANUAL Error Code Name of Part Developer Clutch (DCLM) Confirm the connection of Connector. Is the connection proper between ECN15 of IOD2 and Clutch (DCLM) ? Connect the harness. Is the harness of Clutch (DCLM) broken ? Connect the connector properly.
  • Page 287 CHAPTER 8 TROUBLESHOOTING Error Code Developer Clutch (DCLC) Name of Part Confirm the connection of Connector. Connect the harness. Is the connection proper between ECN16 of IOD2 and Clutch (DCLC) ? Is the harness of Clutch (DCLC) broken ? Connect the connector properly. Is D3 Error cleared ? Complete Check the voltage at DCLC ON-N.
  • Page 288 HL-3450CN SERVICE MANUAL Error Code Name of Part Developer Clutch (DCLK) Confirm the connection of Connector. Is the connection proper between ECN13 of IOD2 and Clutch (DCLK) ? Connect the harness. Is the harness of Clutch (DCLK) broken ? Connect the connector properly.
  • Page 289 CHAPTER 8 TROUBLESHOOTING Error Code Name of Part Developer Solenoid (PSL KY) Confirm the connection of Connector. Is the connection proper between ECN3 of IOD2 and Solenoid (PSL YM) ? Connect the harness. Is the harness of Solenoid (PSL KY) broken ? Connect the connector properly Complete Is D5 Error cleared ?
  • Page 290 HL-3450CN SERVICE MANUAL Error Code Name of Part Developer Solenoid (PSL MC) Confirm the connection of Connector. Is the connection proper between ECN3 of IOD2 and Solenoid (PSL KC) ? Connect the harness. Is the harness of Solenoid (PSL KC) broken ? Connect the connector properly.
  • Page 291 CHAPTER 8 TROUBLESHOOTING Error Code Concerned Part Developer Motor(DM) Is there any unusual rotation noise while printing ? Replace the toner cartridge. Confirm the connection of connector. Is the noise cleared ? Job is complete. Is DCN9 of IOD1 properly connected with connector of DM1? Replace developer gear unit and motor.
  • Page 292 HL-3450CN SERVICE MANUAL Error Code Concerned Part Main Motor(MM) Does a belt cartridge rotate lightly ? Replace the belt cartridge. Does a fuser unit rotate lightly ? Replace the fuser unit. Is E2 error cleared ? Job is complete. Confirm the connection of connector.
  • Page 293 CHAPTER 8 TROUBLESHOOTING Error Code Concerned Part Drum HP Sensor Is a belt cartridge properly installed ? Re-install or replace the belt cartridge. Is an encoder plate deformed ? Does a transfer drum rotate lightly ? Replace the transfer drum. Is a rotation torque excessive ? Confirm the connection of connector.
  • Page 294 HL-3450CN SERVICE MANUAL Error Code Concerned Part Toner Sensor PCB.(LED side) Confirm the connection of a toner sensor PCB.(LED side) connector. Is DCN7 of IOD1 properly connected with a connector of the toner sensor ? Connect them properly. Check the voltage(LEDON-N/P) Is E4 error cleared ? Job is complete.
  • Page 295 CHAPTER 8 TROUBLESHOOTING Error Code Concerned Part Transfer Cam Clutch (TRCM) Confirm the connection of a transfer solenoid connector. Is ECN8 of IOD2 properly connected with a connector of the solenoid ? Connect them properly. Is ECN1 of IOD2 properly connected with 12CN of MCTL PWB ? Is E5 error cleared ? Job is complete.
  • Page 296 HL-3450CN SERVICE MANUAL Error Code Cleaning Brush Solenoid (FBCM) Concerned Part Confirm the connection of a cleaning brush solenoid connector. Connect them properly. Is ECN10 of IOD2 properly connected with a connector of the solenoid ? Is ECN1 of IOD2 properly connected with 11CN of MCTL PWB ? Is E6 error cleared ? Job is complete.
  • Page 297 CHAPTER 8 TROUBLESHOOTING Error Code Cleaner Clutch Concerned Part Confirm the connection of a cleaner clutch connector. Connect them properly. Is ECN11 of IOD2 properly connected with a connector of the clutch ? Is ECN2 of IOD2 properly connected with DCN10 of IOD1 ? Is ECN1 of IOD1 properly connected with 11CN of MCTL PWB ? Is E7 error cleared ? Job is complete.
  • Page 298 HL-3450CN SERVICE MANUAL Error Code Fuser Clutch(FUCL) Concerned Part Confirm the connection of a fuser clutch connector. Connect them properly. Is ECN9 of IOD2 properly connected with a connector of the clutch ? Is ECN1 of IOD2 properly connected with 12CN of MCTL PWB ? Is E8 error cleared ? Job is complete.
  • Page 299 CHAPTER 8 TROUBLESHOOTING Error Code Concerned Part Belt Sensor (PBS) Is a belt cartridge leaned to one side ? Replace the belt cartridge. Install the printer to be leveled out. Is a belt sensor stained ? Clean the belt. Is E9 error cleared ? Confirm the connection of connector.
  • Page 300 HL-3450CN SERVICE MANUAL Error Code Erase Lamp (EL) Concerned Part Confirm the connection of a erase lamp connector. Is DCN7 of IOD1 properly connected with a connector of the erase lamp ? Connect them properly. Is DCN1 of IOD1 properly connected with 11CN of MCTL PWB ? Is EL error cleared ? Job is complete.
  • Page 301 CHAPTER 8 TROUBLESHOOTING Error Code Concerned Part Fan Motor (Control Cooling) Confirm the connection of a fan motor connector. Connect them properly. Is DCN18 of IOD1 properly connected with a connector of the fan motor ? Is DCN1 of IOD1 properly connected with 11CN of MCTL PWB ? Is F0 error cleared ? Job is complete.
  • Page 302 HL-3450CN SERVICE MANUAL Error Code Fan Motor (OZFAN) Concerned Part Confirm the connection of a fan motor connector. Connect them properly. Is ECN5 of IOD2 properly connected with a connector of the fan motor ? Is ECN1 of IOD2 properly connected with 12CN of MCTL PWB ? Is F2 error cleared ? Job is complete.
  • Page 303 CHAPTER 8 TROUBLESHOOTING Error Code Heater Fan (HTFAN) Concerned Part Confirm the connection of a heater fan connector. Connect them properly. Is DCN14 of IOD1 properly connected with a connector of the heater fan ? Is DCN1 of IOD1 properly connected with 11CN of MCTL PWB ? Is F4 error cleared ? Job is complete.
  • Page 304 HL-3450CN SERVICE MANUAL Error Code Concerned Part High-voltage power supply unit (HVU) Confirm the status of a charger unit. Is the charger unit properly installed ? Re-install the charger unit. Is a corona wire cut or shorted ? Replace the charger unit or belt cartridge.
  • Page 305 CHAPTER 8 TROUBLESHOOTING H0 (wire cut/ short error of thermistor) Error Code Fusing Unit Concerned Part Confirm the connection of a fusing unit connector. Re-install the fusing unit. Is the fusing unit properly installed ? Replace the charger unit or belt cartridge. Is there any contact failure due to damaged connector of fusing unit ? Are the connectors properly connected between the fusing unit Connect them properly.
  • Page 306 HL-3450CN SERVICE MANUAL H2,H3,H4 Error Code Concerned Part Fusing Unit and Others Confirm that a fusing heater is lit. Confirm the wiring and connector of the heater. Is the fusing heater controlled for On/Off. Confirm the input voltage. Connect them properly.
  • Page 307 CHAPTER 8 TROUBLESHOOTING Error Code L1 (Beam Detecting Error) Concerned Part Laser Unit Confirm the connection of an laser unit connector. Is the connector PDCN properly connected ? Connect the connector properly. Are the connector LCN1 and LCN of MCTL properly connected ? Is L1 error cleared ? Replace the laser unit.
  • Page 308 HL-3450CN SERVICE MANUAL Error Code Concerned Part Laser Unit Is the connector LCN3 properly connected ? Connect the connector properly. Is L2 error cleared ? Replace the laser unit. Is L2 error cleared ? Replace the MCTL PWB. Job is complete.
  • Page 309 CHAPTER 8 TROUBLESHOOTING Error Code Laser Unit Concerned Part Confirm the connection of an laser unit connector. Connect the connector properly. Is the connector LCN3 properly connected ? Is the connector PDCN properly connected ? Are the connector LCN1 and LCN properly connected ? Is LL error cleared ? Replace the laser unit.

  • Page 310: Image Failure

    HL-3450CN SERVICE MANUAL IMAGE FAILURE (9)-a (9)-b (10) (11) (12) (13) (14) 8-47...
  • Page 311 CHAPTER 8 TROUBLESHOOTING (15)-a (15)-b (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) 244m/m 8-48...
  • Page 312 HL-3450CN SERVICE MANUAL Background Phenomenon Background is smeared due to toner spread as shown in print sample (1) of Page 8-45. Main Causes (1) Too small toner mass and charging level in the developing process. (2) Poor contact of the developer roller’s bias pole.
  • Page 313 CHAPTER 8 TROUBLESHOOTING Jitter Phenomenon Uneven optical density appears periodically in the horizontal direction on the printed image as shown in print sample (3) of Page 8-45. Main Causes (1) Failure of main motor. i) Irregular rotation of the drive motor. ii) Failure of the gears.
  • Page 314 HL-3450CN SERVICE MANUAL Wrinkle / Image Migration Phenomenon Banding shadows of different optical density appear due to wrinkle, image migration and color misregistration occurring on the print paper as shown in print sample (5) of Page 8-45. Main Causes (1) Print paper other than the recommended paper is being used.
  • Page 315 CHAPTER 8 TROUBLESHOOTING White Line (1) Phenomenon Vertical white line appears in the specific color area when test-printed in the four color mode (Stripe Mode), as shown in print sample (6) of Page 8-45. Main Causes (1) Foreign particles adhering to the following places around the developer roller. (Refer to Fig.8-12.) Between the cartridge cover and developer roller (a) On the surface of the developer roller (b)
  • Page 316 HL-3450CN SERVICE MANUAL White Line (2) Phenomenon Vertical white line appears from the leading edge to the trailing edge of the printed image as shown in print sample (7) of Page 8-45. Main Causes The dustproof glass of the laser unit is smeared with toner or foreign particles.
  • Page 317 CHAPTER 8 TROUBLESHOOTING Black Line / Blur in the Image Phenomenon Fine black line or blur appears in the printed image as shown in print sample (9) of Page 8- Main Causes (1) The corona wire of the paper discharger unit is dirty. (2) OPC belt surface is damaged.
  • Page 318 HL-3450CN SERVICE MANUAL I-11 Vertically Staggered Image Phenomenon Printed image staggered in the vertical direction as shown in print sample (11) of Page 8-45. Main Causes (1) Shock or vibration applied to the printer. (2) Failure of the laser unit; vibration from rotation of the scanner motor.
  • Page 319 CHAPTER 8 TROUBLESHOOTING I-13 White Band Phenomenon White banding line appears in the horizontal direction, and consequently causes a missing image as shown in print sample (13) of Page 8-45. Main Causes (1) Installation failure of the transfer unit, and deformation of the transfer roller. (2) Contact failure of the transfer roller bias pole.
  • Page 320 HL-3450CN SERVICE MANUAL I-14 Toner Drop Phenomenon Toner spot stain is caused on the print by toner dropping within the printer engine as shown print sample (14) of Page 8-45. Main Causes (1) Toner drops onto the transfer drum due to the breakdown of the waste toner feeder.
  • Page 321 CHAPTER 8 TROUBLESHOOTING I-15 White Spot / Black Spot Phenomenon White spots and black spots appear on the print as shown in print sample (15) of Page 8-46. Main Causes (1) Foreign particles adhering to the OPC belt or transfer drum. (2) The OPC belt or transfer drum is damaged.
  • Page 322 HL-3450CN SERVICE MANUAL I-17 Color Misregistration Phenomenon Color misregistration is caused between two colors as shown in print sample (17) of Page 8- Main Causes (1) The OPC belt cartridge is not properly installed. (2) The OPC belt cartridge is deformed.
  • Page 323 CHAPTER 8 TROUBLESHOOTING I-19 Mottle Phenomenon Variation of the scanning density is found in the image as shown in print sample (19) of Page 8-46. Main Causes (1) The transfer unit is not fixed in place. (2) Assembly of the transfer roller is inaccurate. (3) THV output of the high-voltage power supply unit is not normal.
  • Page 324 HL-3450CN SERVICE MANUAL I-21 Insufficient Gloss Phenomenon Gloss of the print is not sufficient as shown in print sample (21) of Page 8-46. Main Causes (1) The fuser cleaner is stained. (2) The fuser roller is deteriorated. Countermeasures (1) Replace the fuser cleaner with a new one. (See Section 4.2 of Chapter...
  • Page 325 CHAPTER 8 TROUBLESHOOTING I-23 White Print Phenomenon A blank page (no print at all) is output or a specific color is missing (not printed) as shown in print sample (23) of Page 8-46. Main Causes (1) Laser light path is blocked by paper or other material stuck at the opening of the laser unit.
  • Page 326 HL-3450CN SERVICE MANUAL I-25 Vertical Smear Phenomenon Printed image is smeared vertically as shown in print sample (25) of Page 8-46. Main Causes (1) Paper dust between the cleaning blade and OPC belt. (2) Debris adhering to the base of a toner cartridge’s developer roller where it contacts with the OPC belt.
  • Page 327 CHAPTER 8 TROUBLESHOOTING I-27 Color Missing Phenomenon Color is missing in the printed image as shown in print sample (27) of Page 8-46. Main Causes Fusing failure due to using damp paper or using the printer under high humidity conditions. Countermeasures (1) Use the paper immediately after open the paper bag.

  • Page 328: Appendix 1

    HL-3450CN SERVICE MANUAL APPENDIX 1. SERIAL NO. DESCRIPTIONS The descriptions as below show how to read labels fitted to the printer parts. < ID for production month of the Printer > January September February June October March July November April...
  • Page 329 APPENDIX Toner Cartridge &2/25 X X X X X X X X X X REVISION FACTORY USE DATE OF CARTRIDGE *MONTH OF CARTRIDGE *MONTH OF TONER YEAR OF TONER *1-9 and X for Oct., Y for Nov., Z for Dec. <Location>...
  • Page 330 HL-3450CN SERVICE MANUAL Toner Cartridge, OPC Belt Cartridge Master Box X X X X - X X X REVISION LOT OF MONTH OF TONER CARTRIDGE /BELT CARTRIDGE LOT OF MONTH OF TONER CARTRIDGE /BELT CARTRIDGE LOT MONTH OF TONER/BELT LOT YEAR OF TONER/BELT...
  • Page 331 APPENDIX Laser Unit X X X X X DATE *MONTH YEAR *1-9 and X for Oct., Y for Nov., Z for Dec. <Location> Fig. A- 5 Transfer Drum X X X X X X X X X X DATE *MONTH FACTORY USE YEAR *1-9 and X for Oct., Y for Nov., Z for Dec.
  • Page 332 HL-3450CN SERVICE MANUAL Power Supply Unit S/N X X X X X X X FACTORY USE REV X X YY/WW X X / X X WEEK OF YEAR YEAR OF POWER SUPPLY UNIT <Location> Fig. A- 7...

  • Page 333: Appendix 2

    APPENDIX APPENDIX 2. DIAMETER / CIRCUMFERENCE OF ROLLERS The diameter or circumference of each roller is listed below; Parts Name Diameter (Circumference) OPC Belt (509 mm) Belt Drive Roller 32.4 mm (101.74 mm) Developer Roller 22 mm (69.80 mm) Transfer Roller 25 mm (78.5 mm) Paper Pick-up Roller 40 mm (125.60 mm)

  • Page 334: Appendix 3

    HL-3450CN SERVICE MANUAL APPENDIX 3. SHELF LIFE OF EACH CONSUMABLE Each consumable has its own shelf life as follows. Shelf life varies depending whether the consumable packaging is open or not. Consumable Before unpacking *1 After unpacking *2 Toner cartridge (all colors)

  • Page 335: Appendix 4

    APPENDIX APPENDIX 4. CONSUMABLES REPLACEMENT Each consumable below should be replaced according its own life. Toner Cartridge Life: K = 14,000 prints, CYM = 8,500 pritns Condition: Above figures are based on A4 or letter size 5% coverage. Life is detected by the toner empty sensor.
  • Page 336 HL-3450CN SERVICE MANUAL PR2000101 Cleaning Roller Life: 20,000 pages Condition: Above figure varies depending on coverage. Refer to the list below. Coverage ~ 20% 20% ~ 40% 40% ~ Additional life deleted Life (pages) 20,000 10,000 6,666 Fusing Unit (70K Kit)
  • Page 337 APPENDIX <40,020> 3) Add 20 pages Add figure of <Total pages 34> Figure from <Next care information 32> Modified by the additional life deleted figure <40,000> <40,000> 1) No change This figure is actual next care time 2) 10 pages <39,990>...

  • Page 338: Appendix 5

    HL-3450CN SERVICE MANUAL APPENDIX 5. HOW TO RE-ENTER ORIGINAL DATA TO THE MCTL PWB CAUTION Actions 1) and 2) MUST be carried out BEFORE the MCTL PWB is removed or the NVRAM initialized otherwise ALL READINGS WILL BE LOST. Go into the Engine Controller Mode. (Refer to Section 3 “ENGINE CONTROLLER MODE”...
  • Page 339 APPENDIX After initializing all the data in the NV-RAM on the MCTL PWB, or replacing the MCTL PW B, all the original counter values for the cleaning roller, OPC belt cartridge, fusing unit, 120K kit and 240K kit should be re-entered as below; The method used to correct the counters is to reset the page counter to a calculated TOTAL PAGE value and then to perform a CLEAR CARE for the item to reset the NEXT CARE for that item to the value recorded in 2) iii).
  • Page 340 HL-3450CN SERVICE MANUAL Re-enter the FU UNIT (NC8) value as follows; i) Enter the value of NC8 - LP8 into the TOTAL PAGE counter. (i.e.) NC8 - LP8 = 39,684 - 70,000 = - 30,316 Since the above result is minus, reduce the value of LP8 is 30,000P in order to make the result plus, then enter it into the LIFE PERIOD SET counter in FACTORY MODE.

  • Page 341: Appendix 6

    APPENDIX APPENDIX 6. RE-PACKING INSTRUCTIONS PRECAUTION When re-packing the printer before shipping, be sure to follow the steps and cautions below. Failure to do so will cause toner or oil spill in the printer and severe damage to the printer. Toner Cartridge Open the front cover and remove all the toner cartridges (K, Y, M, C) from the...
  • Page 342 HL-3450CN SERVICE MANUAL OPC Belt Cartridge Open the top cover and remove the OPC belt cartridge from the printer. Open the shutter on the OPC belt cartridge and remove toner in the cartridge with a vacuum cleaner. Fig. A- 10 Cover the OPC belt cartridge with the original protective sheet (black).
  • Page 343 APPENDIX Fusing Unit Remove the fusing unit securing screws (2 pcs.) Screw Screw Fig. A- 13 Holding the handles at both ends of the fusing unit and remove the fusing unit from the printer. Remove the oil bottle and the fuser cleaner from the fusing unit and put each of them into the polyethylene bag.
  • Page 344 HL-3450CN SERVICE MANUAL Waste Toner Pack Remove the waste toner pack from the printer. Waste toner pack Fig. A- 17 Clean toner from around the pack. Waste toner pack Then, remove the seal from the side of the waste toner pack and fit it to cover the hole of the waste toner pack completely.
  • Page 345 APPENDIX 2) Drum cleaner Drum cleaner i) Remove the cleaner cover by releasing the two hooks. ii) Holding the handle located on the top of the drum cleaner, push it backwards. iii) Remove the drum cleaner by lifting it out. Fig.
  • Page 346 HL-3450CN SERVICE MANUAL 4) Paper cassette Media cassette i) Remove the paper cassette from the printer and remove paper from the cassette. ii) Vacuum up any paper dust in the paper cassette. iii) Reinstall the paper cassette. Fig. A- 24...
  • Page 347 APPENDIX Pack the printer, starter kit packing, waste toner pack, and power cable in the carton using the original packing material. Outer carton Starter kit packing Power cable Waste toner pack Printer Fig. A- 27 Seal the outer carton firmly. Band Band the carton with two plastic bands.

  • Page 348: Appendix 7

    HL-3450CN SERVICE MANUAL APPENDIX 7. HIDDEN FUNCTION MENU Line Test Menu Hold down the + and - buttons and turn the print ON LINE TEST ----- < Press the Go button > Item Descriptions LCD TEST All columns of the LCD are turned on to check that the LCDs are all displayed correctly.
  • Page 349 APPENDIX Professional Menu The professional menu is open to users as per request to customize the printer functions mainly. To enter the professional menu, press the Go and Set buttons together. The details for each menu are described as follows; TRAY SETTING TRAY PRIORITY ----- T1>T2(>T3), (T3>)T2>T1 Specifies the priority of the paper source when selecting ‘Auto’...
  • Page 350 HL-3450CN SERVICE MANUAL SAVE SETTINGS SAVE SETTING1 Saves the current printer setting to the user 1. SAVE FONT (Only when selecting the LaserJet emulation.) PRIMARY FONT Saves the fonts to be currently registered as the primary font into the storage device (compact flash card, hard disk).
  • Page 351 APPENDIX TRAYCOMMAND MODE Makes the command to select the paper source compatible with HP LaserJet 3. TRAY COM. = NORM * HP LaserJet 4 command TRAY COM. = SPEC. HP LaserJet 3 command READOUT SELECT Specifies that the printer reads DC3 in the FX emulation or not. READOUT = ON The data is ignored until DC1 is received when DC3 is received.
  • Page 352 Creates the bold or italic font from the bitmap font. CONDENCE SELECT The condensed font is printed at 16.66cpi in the dot printer emulation for the Brother laser printers in conjunction with that the 16.66cpi font is used. However, some customers need the same pitch with the one of the dot printer, and many customers still use the printer at 16.66cpi on the other hand.
  • Page 353 APPENDIX OEM FONT SELECT The special character set is necessary when the printer is supplied to the European countries. For the HL-1260 printer, the special character set is stored into the program ROM additionally. Since the font number is moved due to the addition, the character set is disabled for the normal model.
  • Page 354 HL-3450CN SERVICE MANUAL The priority in each setting is as follows; < When the printer resolution is 600dpi > 3B PRIO = LOW 3B PRIO = HIGH 1. DOWNLOAD 600 1. DOWNLOAD 600 2. DOWNLOAD SCALABLE 2. DOWNLOAD 300 3. CARD 600 3.
  • Page 355 APPENDIX PAPER&TRAY SIZE Specifies the default paper size. DEF PAPER =LT The default paper size is letter for the US and Canada models. DEF PAPER =A4 The default paper size is A4 for the other models. PARALLEL MENU Changes the signal timing of the Centronics interface PARALLEL TIMING CDCC PSW = L The BUSY signal gets high when the STROBE signal goes...
  • Page 356 HL-3450CN SERVICE MANUAL APPLETALK AT/PS Specifies that the emulation is switched to the PS mode forcedly with AppleTalk. APPLE TALK = PS* Switches the emulation to the PS mode with AppleTalk. APPLE TALK = AUTO Uses the auto emulation function with AppleTalk.
  • Page 357 APPENDIX PROTECT OFF MODE Specifies the performance of the page protection function. PRO.OFF = AUTO* Protects the data spuriously even when the page protection is turned off. (Countermeasure for the memory full or print overrun error.) PRO.OFF = NORMAL Specification up to the 4 mask ROM.
  • Page 358 HL-3450CN SERVICE MANUAL JOB TIMEOUT SEL Specifies the setting of the job timeout. Though the job timeout has been set to 5 minutes in the PJL emulation since the HL-1260 printer, the setting to disable the timeout is added due to the user’s request.
  • Page 359 APPENDIX Reset Parts Life The Reset parts life menu is implemented when the service personnel replaces the periodic maintenance parts. For the parts to be replaced easily, however, it is assumed that the user replaces them by him/herself. Therefore the reset parts life menu is distinguished from the service menu described in the next section, ‘4.
  • Page 360 HL-3450CN SERVICE MANUAL Service Menu The service menu provides the printer information for the service personnel. (The following descriptions are not open to other than the service personnel.) To enter the service menu, press the + and Set buttons in this order while holding down the Go button.
  • Page 361 APPENDIX PRINT PAGES Number of printing pages depending on the paper size. (Counted up to 100K.) A4 PAGE The number of printing pages of the A4 size. A4 S PAGE The number of printing pages of the A4 S size. LETTER PAGE The number of printing pages of the letter size.
  • Page 362 HL-3450CN SERVICE MANUAL --SERVICE MENU-- MODIFY COUNT * For modifying of the number of pages and remaining life, the digit to be modified is raised whenever pressing the Set button. The pages and remaining life are fixed on when pressing the Set button on the highest digit.

  • Page 363: Appendix 8

    APPENDIX APPENDIX 8. TO LEVEL THE PRINTER CORRECTLY Please read the leveling instructions described below carefully. If the printer is not installed level, image failures may occur or the life expectancy of the OPC belt cartridge may be shortened. Please do not install the printer as shown in the figures below. Note: If the printer is inclined at 1°...
  • Page 364 HL-3450CN SERVICE MANUAL iii) The table the printer is installed on is not level. Level 1° Fig. A- 31 iv) The table surface the printer is installed on is not strong enough. Level 1° Fig. A- 32 NOTE: If you have a spirit level, put it on the output tray and install the printer as level as possible referring to the level.

  • Page 365: Appendix 9

    APPENDIX APPENDIX 9. PAPER POSITIONS DURING DUPLEX PRINTING Fig. A-34 below shows the paper positions when printing using the available duplex printing function. Fig. A- 34 A-38...

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