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Brother HL-1850 Service Manual

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MODEL: HL-1850/1870N
Read this manual thoroughly before maintenance work.
Keep this manual in a convenient place for quick and easy reference at all times.
March 2003
SM-PRN037
(1)
Brother Laser Printer

SERVICE MANUAL

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  Summary of Contents for Brother HL-1850

  • Page 1: Service Manual

    Brother Laser Printer SERVICE MANUAL MODEL: HL-1850/1870N Read this manual thoroughly before maintenance work. Keep this manual in a convenient place for quick and easy reference at all times. March 2003 SM-PRN037...
  • 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 TrueType is a trademark of Apple computer, Inc.
  • Page 3 (hereinafter 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. This service manual covers the HL-1850/1870N printers. This manual consists of the following chapters:...
  • Page 4: Table Of Contents

    CHAPTER 2 INSTALLATION AND BASIC OPERATION ...... 2-1 CONDITIONS REQUIRED FOR INSTALLATION............2-1 Power Supply ........................2-1 Environment ........................2-1 ® System Requirements for Brother Printer Solution for Windows ........2-1 UNPACKING ......................2-2 INSTALL THE PRINTER ..................2-3 For All Users ........................2-3 3.1.1 Install the drum unit assembly ....................
  • Page 5 HL-1850/1870N SERVICE MANUAL CONTROL PANEL OPERATION................2-19 Data LED Indications ..................... 2-19 Panel Switches Functions ....................2-20 5.2.1 Go switch .......................... 2-20 5.2.2 Job Cancel switch......................2-20 5.2.3 Reprint switch ........................2-21 5.2.4 + & - switch ........................2-24 5.2.5 Set switch ......................... 2-24 5.2.6 Back switch........................
  • Page 6 TABLE OF CONTENTS 1.3.9 Engine I/O ......................... 3-12 1.3.10 Panel I/O ........................... 3-12 Engine PCB........................3-13 BR-net PCB........................3-13 Power Supply ......................... 3-14 1.6.1 Low-voltage Power Supply ....................3-14 1.6.2 High-voltage Power Supply....................3-15 MECHANICS ......................3-16 Overview of Printing Mechanism..................3-16 Paper Transfer .......................
  • Page 7 HL-1850/1870N SERVICE MANUAL 3.10 Process Unit Cover ASSY....................4-25 3.11 Laser Unit........................4-26 3.12 Fixing Unit ........................4-27 3.13 Paper Pick-up Roller ASSY.................... 4-39 3.14 Feed MP Unit ......................... 4-40 3.15 Drive Unit ........................4-42 3.16 Low-voltage Power Supply PCB ASSY................4-47 3.17 Main PCB ASSY......................
  • Page 8 TABLE OF CONTENTS 3.2.2 Causes & countermeasures....................6-19 Paper Feeding Problems ....................6-20 SOFTWARE SETTING PROBLEMS ..............6-22 MALFUNCTIONS ....................6-25 IMAGE DEFECTS ....................6-31 Image Defect Examples ....................6-31 Troubleshooting Image Defect ..................6-32 Location of Grounding Contacts..................6-50 6.3.1 Drum unit .......................... 6-50 6.3.2 Printer body &...
  • Page 9 18. HOW TO USE THE SELF-DIAGNOSTICS TOOLS ..........A-23 19. NVRAM DEFAULT VALUE ................... A-27 20. PAPER CASSETTE INFORMATION (FOR EUROPE ONLY)....... A-28 21. GUIDELINES FOR LEAD FREE SOLDER (MAIN PCB ASSY) ......A-29 22. HOW TO REWRITE HL-1850/1870N FLASH ROM ..........A-30 INDEX...
  • Page 10: Regulation

    This product complies with FDA radiation performance standards, 21 CFR Subchapter J. The label for Chinese manufactured products MANUFACTURED: BROTHER Corporation (Asia) Ltd. Shenzen Buji Nan Ling Factory Gold Garden Ind., Nan Ling Village, Buji, Rong Gang, Shenzen, CHINA This product complies with FDA radiation performance standards, 21 CFR Subchapter J.
  • Page 11 HL-1850/1870N SERVICE MANUAL IEC 825 (220-240V MODEL ONLY) This printer is a Class 1 laser product as defined in IEC 825 specifications. The label shown below is attached in countries where required. This printer has a laser diode which emits invisible laser radiation in the Laser Unit. The Laser Unit should not be opened without disconnecting the two connectors connected with the AC power supply and laser unit.
  • Page 12: Safety Information

    SAFETY INFORMATION SAFETY INFORMATION CAUTION FOR LASER PRODUCT (WARNHINWEIS FUR LASER DRUCKER) CAUTION: When the machine during servicing is operated with the cover open, the regulations of VBG 93 and the performance instructions for VBG 93 are valid. CAUTION: In case of any trouble with the laser unit, replace the laser unit itself. To prevent direct exposure to the laser beam, do not try to open the enclosure of the laser unit.
  • Page 13 HL-1850/1870N SERVICE MANUAL CAUTION INVISIBLE LASER RADIATION WHEN OPEN AND INTERLOCK DEFEATED. AVOID DIRECT EXPOSURE TO BEAM. CLASS 3B LASER PRODUCT. ADVARSEL USYNLIG LASER STRÅLING NÅR KABINETLÅGET STÅR ÅBENT. UNGDÅ DIREKTE UDSÆTTELSE FOR STRÅLING. KLASSE 3B LASER. VARNING OSYNLIG LASERSTRÅLNING NÄR DENNA DEL ÄR ÖPPNAD OCH SPÄRRAR ÄR URKOPPLADE.
  • Page 14 SAFETY INFORMATION DEFINITIONS OF WARNINGS, CAUTIONS AND NOTES The following conventions are used in this service manual: WARNING Indicates warnings that must be observed to prevent possible personal injury. CAUTION: Indicates cautions that must be observed to service the printer properly or prevent damage to the printer.
  • Page 15 HL-1850/1870N SERVICE MANUAL xiii...
  • Page 16: Chapter 1 General

    HL-1850/1870N SERVICE MANUAL CHAPTER 1 GENERAL FEATURES This printer has the following features; High Resolution and Fast Print Speed True 600 x 600 dots / true 300 x 300 dots per inch (dpi) and 2400 x 600 dots per inch (dpi) for graphics with microfine toner and up to 18 pages per minutes (ppm) print speed for A4 and 19 pages per minutes (ppm) print speed for Letter paper.
  • Page 17 HL-1850/1870N printers. The printers also support auto- emulation switching between HP, Brother BR-Script 3 and Epson or HP, BR-Script 3 and IBM. If you want to set the printer emulation, you can do it using the Remote Printer Console Program.
  • Page 18: Overview

    HL-1850/1870N SERVICE MANUAL OVERVIEW <Front View> Face down output tray Extension flap Control panel Front cover Cover release button Multi-purpose tray extension Multi-purpose tray Paper cassette Fig. 1-1 <Rear View> Parallel interface connector Face up output tray Face up tray extension...
  • Page 19: Specifications

    CHAPTER 1 GENERAL SPECIFICATIONS Printing Print method Electrophotography by semiconductor laser beam scanning Laser Wavelength: 780 nm Output: 5mW max ® ® ® Resolution HQ1200 (for Windows 95/98/Me, WindowsNT 4.0, Windows 2000/XP, and Mac OS) ® ® ® 600 dpi (for Windows 95/98/Me, WindowsNT 4.0, Windows 2000/XP, DOS and Mac OS)
  • Page 20: Functions

    HL-1850/1870N SERVICE MANUAL Functions Fujitsu MB86834 100MHz  Emulation Brother Printing Solution for Windows Automatic emulation selection among HP LaserJet (PCL level 6), Brother BR-Script Level 3, EPSON FX-850 or IBM Proprinter XL Printer driver <PCL Driver>   Windows 95/98/Me, Windows NT 4.0, Windows®...
  • Page 21: Electrical And Mechanical

    Europe and Australia: AC 220 to 240V, 50 Hz/60 Hz Power consumption Printing (average): 410 W or less Standing by: 70 W or less Sleep*: 9 W or less (for HL-1850) 10 W or less (for HL-1870N) Noise Printing: 50dB A or less Standing by: 30dB A or less...
  • Page 22: Network

    • Web Based Management (HTTPD) Management • BRAdmin Professional (using TCP/IP protocol and IPX/SPX) • SNMP, MIB II as well as Brother private MIB • TELNET command console (NIC only) • HP JetAdmin compatible • BRCONFIG DOS Utility (NIC only, needs Netware network) •...
  • Page 23: Paper

    CHAPTER 1 GENERAL Paper 3.5.1 Feedable paper (1) Paper type Upper Multi- Optional Select the paper Duplex Paper type paper purpose lower type from the printing tray tray tray printer driver Plain paper Plain paper 60 g/m to 105 g/m (16 to 28 lbs.) Plain paper Recycled paper...
  • Page 24 HL-1850/1870N SERVICE MANUAL 4% to 6% by weight Moisture content <Multi-purpose tray> Cut sheet Envelope Basis weight 60 to 161 g/m (16 to 43 lb.) 75 to 90 g/m (20 to 24 lb.) single thickness Caliper 0.08 to 0.2 mm (0.003 to 0.008 in.) 0.084 to 0.14 mm (0.003 to 0.005 in.)
  • Page 25: Paper Cassette Capacity

    CHAPTER 1 GENERAL 3.5.2 Paper cassette capacity Upper Multi-purpose Optional lower tray paper tray tray 100 sheets 250 sheet 250 sheets (80 g/m or 20 lbs.) (80 g/m or 20 lbs.) (80 g/m or 20 lbs.) Paper Legal: 30 Capacity 8.5x13 in.: 30 Label stock: 10 3.5.3...
  • Page 26: Pcl5E/Epson/Ibm Emulation

    HL-1850/1870N SERVICE MANUAL Printable Area 3.6.1 PCL5e/EPSON/IBM emulation The figure below shows the printable area each emulation guarantees when printing on Portrait and Landscape. 1-11...
  • Page 27 CHAPTER 1 GENERAL The table below shows the printable areas when printing on Portrait for each paper size. Size 215.9 mm 279.4 mm 203.2 mm 279.4 mm 6.35 mm 4.2 mm 8.5” 11.0” 8.0” 11.0” 0.25” 0 mm 0.16” Letter (2,550 dots) (3,300 dots) (2,400 dots)
  • Page 28 HL-1850/1870N SERVICE MANUAL 1-13...
  • Page 29: Pcl6/Br-Script3 Emulation

    CHAPTER 1 GENERAL The table below shows the printable areas when printing on Landscape for each paper size. Size 279.4 mm 215.9 mm 269.3 mm 215.9 mm 5.0 mm 4.2 mm 11.0” 8.5” 10.6” 8.5” 0.2” 0 mm 0.16” Letter (3,300 dots) (2,550 dots) (3,180 dots)
  • Page 30: Chapter 2 Installation And Basic Operation

    • Do not cover the slots in the side cover.     System Requirements for Brother Printer Solution for Windows Check the following system requirements to setup and operate the printer using Brother  Printing Solution for Windows...
  • Page 31: Unpacking

    CHAPTER 2 INSTALLATION AND BASIC OPERATION UNPACKING When unpacking the printer, check to see that all of the following components are included in the carton. Paper cassette Printer Drum unit Documents (with Toner cartridge included) CD-ROM AC cord Fig. 2-1 NOTE: Components may vary depending on the country.
  • Page 32: Install The Printer

    HL-1850/1870N SERVICE MANUAL INSTALL THE PRINTER You need to implement hardware setup and driver installation to use the printer. ® ® Firstly, identify the Operating System on your computer. (Windows 95/98/Me, Windows NT 4.0, Windows ® 2000/XP and Macintosh)Then, purchase the appropriate interface cable (Parallel, USB or Network) for your computer.
  • Page 33: Install The Drum Unit Assembly

    CHAPTER 2 INSTALLATION AND BASIC OPERATION 3.1.1 Install the drum unit assembly (1) Press the cover release button, and then open the front cover. Unpack the drum unit assembly. Rock it from side to side 5 or 6 times to distribute the toner evenly inside the assembly.
  • Page 34: Print A Test Page

    HL-1850/1870N SERVICE MANUAL Load paper into the paper cassette. Check that the paper is flat in the tray and below the maximum paper mark. Fig. 2-5 Re-install the paper cassette into the printer. 3.1.3 Print a test page (1) Make sure the printer power switch is off. Connect the AC power cord to the printer. Do not connect the interface cable.
  • Page 35: For Windows ® Users

    Connect the USB interface cable to the PC, and then connect it to the printer. NOTE: If “The file brUSGcfg.exe on Brother USB Printer class…” message appears, click the Browse… button, and then select the CD-ROM drive. Select the DRIVER\WIN98MEUSB directory, and then click the OK button.
  • Page 36 Install the BRAdmin Professional Configuration utility The BRAdmin Professional software provides sophisticated network and printer management capabilities for Brother and non-Brother products. By identifying potential problems before they arise, and by addressing important IT requirements such as streamlined printer configuration, mass configuration and enterprise-wide upgrades, the BRAdmin Professional software plays an important role in printer network management.
  • Page 37 Connect the cable to your printer, and then connect it to a free port on your hub. Turn the printer power switch on. Click the Next button. Select the Network shared printer or the Brother peer-to-peer network printer, and then click the Next button. Select the network connection style and follow the instructions below: 3.
  • Page 38 HL-1850/1870N SERVICE MANUAL 4. For Brother Peer-to-Peer network printer users (LPR-recommended Peer-to-Peer printing method) Configuring the LPR port <For Windows ® 95/98/Me users> (1) Select “LPR (Recommended)” and then click the Next button. (2) Enter a unique port name (ex. BLP1), and then click the OK button.
  • Page 39: For Macintosh Users

    (10) Click the Change…button in USB Printer Selection. Select HL-1850/1870N series, and then click the OK button. (11) Click the Create…button. (12) Enter your printer name (HL-1850/1870N series), and then click the Save button. (13) Select Quit from the File menu. 2-10...
  • Page 40 HL-1850/1870N SERVICE MANUAL For network users Connect the printer to the Macintosh & install the BR-Script PPD file (1) Double click the BR-Script PPD Installer icon and then follow the instructions on the screen. (2) Turn the printer power switch off.
  • Page 41: Printing Methods

    CHAPTER 2 INSTALLATION AND BASIC OPERATION PRINTING METHODS The printer provides two types of printing method; printing from the paper cassette and printing from the multi-purpose tray. Printing from the Paper Cassette You can load plain paper, recycled paper or transparencies into the paper cassette. If paper is loaded into the paper cassette, the printer automatically feeds paper sheet by sheet and ejects the printed page into the output tray.
  • Page 42 HL-1850/1870N SERVICE MANUAL (3) Place paper in the multi-purpose tray so it touches the back of the tray and remains below the limit mark. Fig. 2-15 NOTE: Note the following when placing paper on the multi-purpose tray: • If the paper to be printed on weighs more than 135 g/m (36 lbs), use the face up output tray.
  • Page 43: Printing On Envelopes (Face Up Printing)

    CHAPTER 2 INSTALLATION AND BASIC OPERATION 4.2.1 Printing on envelopes (Face up printing) Use of any of the envelopes listed below may cause damage to the printer. Such damage is not covered under any warranty or service agreement. • Envelopes that are damaged, curled, wrinkled, or irregularly shaped •...
  • Page 44: Printing On Label, Transparency, Etc

    HL-1850/1870N SERVICE MANUAL NOTE: Note the following when placing paper on the multi-purpose tray: • Insert the leading edge of the paper first and push it gently into the tray. • The top of the paper stack must be under the guides that are on both sides of tray. The maximum thickness is 11 mm (or 0.43 inch).
  • Page 45 CHAPTER 2 INSTALLATION AND BASIC OPERATION CAUTION: Do not touch transparencies that have just been printed because they are very HOT. 2-16...
  • Page 46 HL-1850/1870N SERVICE MANUAL When printing on labels or transparencies, follow the steps below; (1) Open the multi-purpose tray. (2) Unfold the multi-purpose tray extension. For printing on labels, open the face up output tray. When printing on transparencies, print to the face down output tray.
  • Page 47: Printing To The Face Up Output Tray (Face Up Printing)

    CHAPTER 2 INSTALLATION AND BASIC OPERATION Printing to the Face up Output Tray (Face up Printing) When the face up output tray is open, the printer has a straight paper path from the paper cassette or multi-purpose tray to the rear of the printer. Use this output method when printing on special media that is thick or should not be bent, such as heavy paper, labels, transparencies, card stock or envelopes.
  • Page 48 HL-1850/1870N SERVICE MANUAL If the paper adjustment lever for duplex printing is not correctly set for the paper size, paper jams may occur and the printing will be out of position on the paper. 2-19...
  • Page 49: Manual Feed

    CHAPTER 2 INSTALLATION AND BASIC OPERATION (3) Open the Property tab in the printer driver. Select the duplex printing mode in the Paper tab, and then click the OK button. The printer will print on both sides of the paper automatically.
  • Page 50: Control Panel Operation

    HL-1850/1870N SERVICE MANUAL Control Panel Operation There are one LED and 7 switches on the control panel. The LED and LCD display indicate the printer status, and pressing the switches enables several functions in the printer. The display also shows the current printer status. When you use the control panel switches, the display will change.
  • Page 51: Panel Switches Functions

    CHAPTER 2 INSTALLATION AND BASIC OPERATION Panel Switches Functions You can control the basic printer operations and change various printer settings with 7 control panel switches (Go, Cancel, Reprint, +, -, Set, Back). Function Exit from the control panel menu. Reprint settings and Error messages.
  • Page 52: Reprint Switch

    HL-1850/1870N SERVICE MANUAL 5.2.3 Reprint switch If you want to reprint a document that has just been printed, you can reprint it by pressing the Reprint switch. Also, if you have created a document that you wish to share with colleagues, simply spool the document to a non-secure area of the printer.
  • Page 53 CHAPTER 2 INSTALLATION AND BASIC OPERATION Reprint the last job 3 times 1. Set the REPRINT menu ON with SETUP mode using the control panel 2. Press the Reprint switch. If you wait too long to continue the COPIES= switch panel operation, the display exits the REPRINT menu automatically.
  • Page 54 HL-1850/1870N SERVICE MANUAL Operations for printing secure data If there is no data. NO DATA STORED Press the Reprint switch. LAST JOB Press + or - SECURE Press Set USER XXXXXXX Press + or – to select the user name.
  • Page 55: Switch

    CHAPTER 2 INSTALLATION AND BASIC OPERATION 5.2.4 + & - switch If you press the + or – switch when the printer is in the on-line state (READY), it turns off-line and the LCD displays the menu. (1) To display menus in the current mode If you press the + or –...
  • Page 56: Backlights

    HL-1850/1870N SERVICE MANUAL PR2001022 5.3.1 Backlights The backlight of the LCD shows the current printer status with the different colors and the light indications (on, off and blinking). Signal Status The printer is in sleep status. Green (General) Warming up...
  • Page 57: Printer Status Messages

    CHAPTER 2 INSTALLATION AND BASIC OPERATION 5.3.2 Printer status messages The following table shows the printer status messages that are displayed during normal operation: Printer Status Message Meaning Ready to print. READY Busy processing data. PROCESSING In sleep status (power save mode). SLEEP Printing.
  • Page 58: How To Use The Control Panel

    HL-1850/1870N SERVICE MANUAL How to Use the Control Panel The followings are the basic steps when operating the switches; Menu, +, –, Set, and Back. • If no control panel operations are performed for 30 seconds, the LCD automatically returns to READY.
  • Page 59: Control Panel Setting Menu

    CHAPTER 2 INSTALLATION AND BASIC OPERATION Control Panel Setting Menu There are 8 modes. For more information about the selections available for each mode, refer to the pages listed below. INFORMATION For more information, see subsection 5.5.1 ‘INFORMATION’ in this Chapter. PAPER For more information, see subsection 5.5.2 ‘PAPER’...
  • Page 60: Information

    HL-1850/1870N SERVICE MANUAL 5.5.1 Information Setting Menu Description Print the configuration page. PRINT SETTINGS Print the test page. PRINT TEST Print the demonstration. PRINT DEMO Print the file list. PRINT FILE LIST Print the font list and samples. PRINT FONTS...
  • Page 61: Quality

    CHAPTER 2 INSTALLATION AND BASIC OPERATION PR2001022 5.5.3 Quality Setting Menu Description =300 / 600 / HQ1200 RESOLUTION You can choose a print resolution of 300, 600 or HQ1200. =OFF / LIGHT / MEDIUM/DARK HRC: High Resolution Control offers improved print quality of characters and graphics that conventional laser printers cannot attain with a resolution of 300 or 600 dpi.
  • Page 62: Print Menu

    HL-1850/1870N SERVICE MANUAL PR2001022 5.5.5 Print menu Setting Menu Description =PLAIN PAPER / TRANSPARENCIES / THIN PAPER / THICK MEDIA TYPE PAPER / THICKER PAPER / BOND PAPER / ENVELOPES / ENV.THICK / ENV.THIN Set cup sheet paper size to Letter, Legal, A4, A5, A6, B5, B6, PAPER Executive, COM10, Monarch, C5 and DL…...
  • Page 63 CHAPTER 2 INSTALLATION AND BASIC OPERATION =OFF / ON AUTO SKIP=ON Line feed and carriage return occur when the printer position reaches the bottom margin. Setting Menu Description =#### HP LASERJET LEFT MARGIN Set the left margin at column 0 to 126 columns at 10 cpi.
  • Page 64 HL-1850/1870N SERVICE MANUAL =#### BOTTOM MARGIN Set the bottom margin a distance from the top edge of the paper: 0, 0.33, 0.5, 1.0, 1.5 or 2.0” Factory setting=0.33 =#### LINES Set the number of lines per page from 5 to 128 lines.
  • Page 65 CHAPTER 2 INSTALLATION AND BASIC OPERATION Setting Menu Description =I0000:????? IBM PROPRINTER FONT NO. FONT PITCH/ =???.?? POINT PC-8 / … SYMBOL/ Set the symbol set or the character set. CHARACTER SET Print code table. TABLE PRINT =OFF / ON AUTO LF=OFF ON: CR CR+LF OFF: CR CR...
  • Page 66: Network

    HL-1850/1870N SERVICE MANUAL PR2001022 5.5.6 Network Setting Menu Description Sub-setting Menu Description TCP/IP =ON / OFF TCP/IP ENABLE ###, ###, ###, ### IP ADDRESS= ###, ###, ###, ### SUBNET MASK= ###, ###, ###, ### GATEWAY= IP BOOT TRIES =AUTO / STATIC / RARP / BOOTP /...
  • Page 67: Reset Menu

    CHAPTER 2 INSTALLATION AND BASIC OPERATION 5.5.8 Reset menu Setting Menu Description Resets the printer and restores all printer settings – including RESET PRINTER command settings – to settings you have previously made with the control panel switches. Resets the printer and restores all printer settings – including FACTORY RESET command settings –...
  • Page 68: 5.5.10 About Emulation Modes

    HL-1850/1870N SERVICE MANUAL 5.5.10 About emulation modes This printer has the following emulation modes. HP LserJet Mode The HP LaserJet mode (or HP mode) is the emulation mode in which this printer emulates the Hewlett-Packard LaserJet laser printer. Many software applications support this type of laser printer.
  • Page 69 CHAPTER 2 INSTALLATION AND BASIC OPERATION password and IP address information) hold down the Network Test Button of the Network board (NC-4100h) for more than 5 seconds. 2-40...
  • Page 70 HL-1850/1870N SERVICE MANUAL Mode Menu Factory Setting =AUTO PAPER SOURCE =MP>T1>T2 TRAY PRIORITY =OFF MP FIRST =A4 / LTR MP SIZE =OFF MANUAL FEED =ANY TRAY1 SIZE =ANY TRAY2 SIZE =OFF DUPLEX =600 QUALITY RESOLUTION =MEDIUM =OFF TONER SAVE DENSITY...
  • Page 71 CHAPTER 2 INSTALLATION AND BASIC OPERATION Mode Menu Factory Setting FONT NO.=59 PRINT MENU HP LASER JET FONT PITCH / POINT=10.00 / 12.00 SYMBOL / CHARACTER SET=PC8 AUTO LF=OFF AUTO CR=OFF AUTO WRAP=OFF AUTO SKI=ON LEFT MARGIN=#### RIGHT MARGIN=#### TOP MARGIN=#### BOTTOM MARGIN=#### LINES=#### FONT NO.=59...
  • Page 72 HL-1850/1870N SERVICE MANUAL Mode Menu Factory Setting TCP/IP ENABLE=ON NETWORK TCP/IP IP METHOD=AUTO IP ADDRESS=192.0.0.192 SUBNET MASK=0.0.0.0 GATEWAY=0.0.0.0 IP BOOT TRIES=3 IP METHOD=AUTO NETWARE ENABLE=ON NETWARE NEE FRAME=AUTO APPLETALK NETBEUI DLC/LLC BANYAN NETBIOS/IP =AUTO ENET 2-43...
  • Page 73: Other Control Features

    CHAPTER 2 INSTALLATION AND BASIC OPERATION Other Control Features The printer has the following useful features; 5.6.1 Sleep mode When the printer does not receive data for a certain period of time (timeout), it enters sleep mode. The default timeout is 5 minutes and it is automatically adjusted to the most suitable time-out setting depending on the frequency of your printer use (Intelligent Sleep Mode).
  • Page 74: Network Board Operation

    HL-1850/1870N SERVICE MANUAL NETWORK BOARD OPERATION Installing the network board enables you to use the printer in the TCP/IP, IPX/SPX, AppleTalk, DLC/LLC, Banyan VINES, DEC LAT and NetBEUI environments. Also, useful utilities such as BR-Admin32 and network printing software for the administrator are included. For more information about set up, see section 3.
  • Page 75 CHAPTER 2 INSTALLATION AND BASIC OPERATION (6) Insert the network board connector into the PCB connector, and then secure it with the two screws removed in (4).  Fig. 2-33 (7) Re-install the PCB access plate, and then secure it with the two screws removed in (3). (8) Close the interface cover.
  • Page 76: Functions

    HL-1850/1870N SERVICE MANUAL Functions 6.2.1 LED functions A-LED (Green) F-LED (Orange) L-LED (Green)      Fig. 2-35 L-LED (Green): Link activity This LED is on if there is a valid connection to the network (either 10BaseT or 100BaseTX). It is off if no network is detected.
  • Page 77 CHAPTER 2 INSTALLATION AND BASIC OPERATION 2-48...
  • Page 78: Chapter 3 Theory Of Operation

    HL-1850/1870N SERVICE MANUAL CHAPTER 3 THEORY OF OPERATION ELECTRONICS General Block Diagram HL-1850 HL-1870N Fig. 3-1 shows a general block diagram of the HL-1850 and the HL-1870N printers. Network board (Standard for HL-1670N Option for HL-1650) Optional RAM (DIMM) Ethernet (max. 128Mbytes)
  • Page 79: Main Pcb Block Diagram

    CHAPTER 3 THEORY OF OPERATION Main PCB Block Diagram HL-1850 HL-1870N Fig. 3-2 shows the block diagram of the main PCB of the HL-1850 and the HL-1870N printers. A S I C CPU Core (MB86834) Oscillator (48MHz) Reset Circuit Address Decoder...
  • Page 80: Main Pcb

    HL-1850/1870N SERVICE MANUAL Main PCB For the entire circuit diagram of the main PCB, see APPENDIX 2. to 7. ‘MAIN PCB CIRCUIT DIAGRAM, HL-1850/1870N in this manual. 1.3.1 ASIC HL-1850 HL-1870N A Fujitsu 32bit RISC CPU, MB86834 (SPARC lite) is built in the ASIC. While the CPU is driven with a clock frequency of 48 MHz in the user logic block, it itself runs at 96 MHz, which is generated by multiplying the source clock by two.
  • Page 81 CHAPTER 3 THEORY OF OPERATION (2) USB interface Stores the data received from the PC into DRAM as controlled by the DMA controller. The transmission speed is 12Mbps. Fig. 3-4 (3) Engine GA transfer circuit Communicates with the engine GA by a full-duplex synchronous serial method. The communication speed is 520Kbps.
  • Page 82 HL-1850/1870N SERVICE MANUAL Fig. 3-5...
  • Page 83: Rom

    CHAPTER 3 THEORY OF OPERATION 1.3.2 HL-1850 HL-1870N Two 64 Mbits ROMs (x 16 bit) are fitted. Fig. 3-6...
  • Page 84: Flash Rom

    HL-1850/1870N SERVICE MANUAL 1.3.3 Flash ROM HL-1850 HL-1870N Two 8 Mbits flash ROMs (x 16 bit) are fitted. Fig. 3-7...
  • Page 85: Sdram

    CHAPTER 3 THEORY OF OPERATION 1.3.4 SDRAM HL-1850 A 64M-bit SDRAM (x 32 bits) is used as the RAM. Fig. 3-8...
  • Page 86 HL-1850/1870N SERVICE MANUAL HL-1870N Two 64M-bit SDRAMs (x 16 bits) are used as the RAM. Fig. 3-9...
  • Page 87: Optional Ram

    CHAPTER 3 THEORY OF OPERATION 1.3.5 Optional RAM HL-1850 HL-1870N A 32bit (100 pin) DIMM can be fitted as optional RAM. The main PCB has one slot and the capacity of DIMM can be from 16 Mbyte to 128 Mbytes.
  • Page 88: Pci Bus

    HL-1850/1870N SERVICE MANUAL 1.3.6 PCI bus HL-1850 HL-1870N The interface of the PCI bus is PCI specification revision 2.2 compliant. Fig. 3-11 3-11...
  • Page 89: Eeprom

    CHAPTER 3 THEORY OF OPERATION 1.3.7 EEPROM HL-1850 HL-1870N The EEPROM is M24C64 type of two-wire method with a 8192 x 8 bits configuration. Fig. 3-12 1.3.8 Reset circuit HL-1850 HL-1870N The reset IC is a S-80928ANMP. The reset voltage is 2.7V (typ.) and the LOW period of reset is 260ms (typ.)
  • Page 90: Engine I/O

    HL-1850/1870N SERVICE MANUAL 1.3.9 Engine I/O HL-1850 HL-1870N Fig. 3-19 shows the engine interface circuit. The interface with the engine PCB is by full- duplex synchronous serial method. Fig. 3-14 1.3.10 Panel I/O HL-1850 HL-1870N Fig. 3-15 shows the panel interface circuit. The interface with the panel PCB is by full-duplex synchronous serial method.
  • Page 91 CHAPTER 3 THEORY OF OPERATION Fig. 3-15 3-14...
  • Page 92: Engine Pcb

    HL-1850/1870N SERVICE MANUAL Engine PCB The gate array which transforms the serial signal from the main PCB into the parallel signal is mounted on the engine PCB. The engine PCB controls the following parts by using the transferred signal data;...
  • Page 93: Power Supply

    CHAPTER 3 THEORY OF OPERATION Power Supply 1.6.1 Low-voltage power supply The power supply uses a switching regulation system to generate the regulated DC power (+3.3V, +7V [non regulated] and +24V), which are converted from the AC line. The regulated output and the production code of each power supply are listed below; Regulated Output Production Code +3.3V / 1.0A...
  • Page 94: High-Voltage Power Supply

    HL-1850/1870N SERVICE MANUAL 1.6.2 High-voltage power supply The high-voltage power supply generates and outputs the voltages and currents for the charging, development and transfer functions. For the circuit diagram of the high-voltage power supply PCB, see APPENDIX 13. ‘HIGH- VOLTAGE POWER SUPPLY PCB CIRCUIT DIAGRAM’...
  • Page 96 HL-1850/1870N SERVICE MANUAL Panel PCB Laser Unit H Network Laser Board (HL-1670N) Polygon Motor Drum Unit Primary Charger (Corona Wire) Primary Charger (Grid) Main PCB Engine PCB High- Development Roller Voltage Front Power Supply Roller Registration Supply Sensor Low-Voltage Transfer Roller...
  • Page 97: Paper Transfer

    CHAPTER 3 THEORY OF OPERATION Paper Transfer 2.2.1 Paper supply The paper pick-up roller picks up one sheet of paper from the paper cassette every time it is rotated and feeds it to the paper feed roller. First feed roller First feed pinch roller Paper feed pinch roller Paper feed roller...
  • Page 98 HL-1850/1870N SERVICE MANUAL The rear registration sensor in the path from the feed roller to the transfer roller controls the first print position on the paper. 3-21...
  • Page 99: Paper Eject

    CHAPTER 3 THEORY OF OPERATION 2.2.3 Paper eject After the printing image on the photosensitive drum is transferred onto the paper, the paper is fed to the fixing unit to fix unfixed toner onto the paper. Afterwards, the paper is ejected from the fixing unit by the first eject roller in the fixing unit. The eject sensor lever detects whether the paper is ejected correctly or not.
  • Page 100: Sensors

    HL-1850/1870N SERVICE MANUAL Sensors 2.3.1 Cover sensors Detect opening and closing of the front cover. Shutter arm C MP sensor PCB assy Fig. 3-24 2.3.2 Toner sensors Detects if there is toner in the toner cartridge. The toner sensor at the left side emits light through the window on the left side of the toner cartridge, then the toner sensor at the right side receives it when the toner is low.
  • Page 101 CHAPTER 3 THEORY OF OPERATION 3-24...
  • Page 102: Dx Tray Sensor / Dx Paper Size Sensor

    HL-1850/1870N SERVICE MANUAL 2.3.3 DX tray sensor / DX paper size sensor The DX tray sensor detects if the DX tray in installed, and the DX tray size sensor detects if the correct size of paper is selected. DX sensor PCB assy Fig.
  • Page 103: Cassette Sensor / Paper Empty Sensor

    CHAPTER 3 THEORY OF OPERATION 2.3.5 Cassette sensor / Paper empty sensor Detect if the paper cassette is installed. They also detect if there is paper in the paper cassette. Feed MP unit Cassette sensor PCB assy Fig. 3-28 2.3.6 Paper eject sensor Detects if paper is ejected from the fixing unit.
  • Page 104: Drum Unit

    HL-1850/1870N SERVICE MANUAL Drum Unit 2.4.1 Photosensitive drum Generates the latent electrostatic image and develops the image on the drum surface. 2.4.2 Primary charger Forms a uniform charge on the drum surface. (1) Corona wire Generates the ion charge on the drum.
  • Page 105: Exposure Stage

    CHAPTER 3 THEORY OF OPERATION 2.6.2 Exposure stage After the drum is positively charged, it is exposed to the light emitted from the laser unit. Drum Laser beam Paper Laser beam f θ lens Laser detector Polygon mirror Laser diode Motor Lens Fig.
  • Page 106: Developing

    HL-1850/1870N SERVICE MANUAL 2.6.3 Developing Developing causes the toner to be attracted to the electrostatic image on the drum so as to transform it into a visible image. The developer consists of a non-magnetic toner. The development roller is made of conductive rubber and the supply roller (which is also made of conductive sponge) rotate against each other.
  • Page 107: Fixing Stage

    CHAPTER 3 THEORY OF OPERATION 2.6.5 Fixing stage The image transferred to the paper by static electricity is fixed by heat and pressure when passing through the heat roller and the pressure roller in the fixing unit. The thermistor keeps the surface temperature of the heat roller constant by detecting the surface temperature of the heat roller and turning on or off the halogen heater lamp.
  • Page 108: Chapter 4 Disassembly And Re-Assembly

    HL-1850/1870N SERVICE MANUAL CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY SAFETY PRECAUTIONS To avoid creating secondary problems by mishandling, follow the warnings and precautions below during maintenance work. WARNING (1) Always turn off the power switch and unplug the power cord from the power outlet before accessing any parts inside the printer.
  • Page 109 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY...
  • Page 110: Disassembly Flow

    HL-1850/1870N SERVICE MANUAL DISASSEMBLY FLOW AC CORD BASE PLATE LASER UNIT DRUM UNIT ENGINE PCB ASSY PAPER CASSETTE FIXING UNIT / HIGH-VOLTAGE PS PCB ASSY NETWORK BOARD PAPER PICK-UP ROLLER ASSY TOP COVER EXIT ROLLER UNIT DX SENSOR FEED MP UNIT...
  • Page 111: Disassembly Procedure

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY DISASSEMBLY PROCEDURE NOTE: Refer to the subsection “3.27 Harness Winding Form” in this Chapter when re-assembling printer parts. AC Cord (1) Disconnect the AC cord from the printer AC inlet. AC cord Printer AC inlet Fig.
  • Page 112: Paper Cassette

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY Paper Cassette (1) Close the MP cover and pull out the paper cassette from the printer and remove the paper from the cassette. MP cover Paper cassette Fig. 4-3 (2) Remove the pad holder ZLh ASSY JPN by pulling it upwards, then remove the separation pad spring 350 from the paper cassette.
  • Page 113 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY NOTE: When replacing/re-assembling the pad holder ZLh ASSY, remove the old grease and apply a suitable amount of grease referring to the figure below; Paper pick-up roller Grease: Molykote PG-662 Paper cassette (1 rice-grain size) Fig.
  • Page 114 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (5) Keeping the paper cassette upside down, release the pressure roller holder assembly from the cassette by releasing the metal mounting plate from the plastic retaining boss. Use a flat screwdriver to press the metal plate forwards until it clears the boss and then remove the pressure roller holder assembly downwards from the cassette.
  • Page 115 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (10) Turn the cassette the correct way up and slide the two paper guides to the center of the cassette. (11) Remove the side guides Right and Left from the paper cassette. Side guide L Side guide R Paper cassette Fig.
  • Page 116 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY NOTE: When re-assembling the pressure plate ASSY, ensure that the paper indicator arm is under the pressure plate. CAUTION: When unhooking the catches to remove the pressure plate, do not bend the pressure plate, gently ease the plastic cover. If the pressure plate is deformed, paper feeding problems may occur.
  • Page 117 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (17) 32Turn the cassette upside down and remove the one cup B M3x8 Taptite screw to remove the side guide gear. Then remove the one friction spring. (18) Remove the two side guide racks. (19) Remove the paper indicator. Taptite, cup B M3x8 Side guide rack Side guide gear...
  • Page 118 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (20) Remove the pan B M3x8 Taptite screw to remove the tray lock lever from the paper cassette. (21) Unhook the four catches to remove the paper tray rear from the paper cassette. Taptite,pan B M3x8 Tray lock lever Paper tray rear (catch)
  • Page 119: Network Board (For Hl-1870N Only)

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY Network Board (For HL-1870N only) (1) Open the access cover by sliding it to the backward. (2) Loosen the two bind S M3x8 Taptite screws to remove the PCB access plate. PCB access plate Access cover Taptite, bind S M3x8 Printer Fig.
  • Page 120: Top Cover

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY Top Cover (1) Open the Process unit cover ASSY. (2) Remove the four shoulder screws from the side cover R and L. (3) Open the rear cover and disconnect the two harnesses for the panel PCB ASSY. (4) Remove the top cover from the printer.
  • Page 121 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (6) Turn the top cover upside down and remove the three cup B M3x8 Taptite screws from the top cover. (7) Turn the top cover the correct way up to remove the panel cover ASSY from the top cover. Taptite,cup B M3x8 Panel cover ASSY Top cover (Back side)
  • Page 122 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (10) Remove the LCD holder from the panel cover ASSY and remove the back light PCB ASSY by releasing two hooks from ASSY. (11) Remove the LCD from the panel PCB ASSY by releasing two hooks and then remove the diffusion film from the ASSY.
  • Page 123 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (12) Remove the panel light guide, and then remove the key from the panel cover. Panel light guide Panel cover Fig. 4-24 (13) Remove the key top A and the key top B form the key. Key top A Key top B Fig.
  • Page 124: Dx Feed Assy

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY DX Feed ASSY (1) Close the rear cover and remove the DX feed ASSY from the printer. Rear cover DX feed ASSY Fig. 4-26 (2) Remove the bind M3x4 screw to remove the ground wire cover and the ground wire from the paper guide upper ASSY, and then remove the ground wire from the ground wire cover.
  • Page 125 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (4) Remove the roller holder using a pair of tweezers from the paper guide upper ASSY while pushing the pressure roller slightly down to assist the roller holder being released. (boss) Roller holder Pressure roller Paper guide upper ASSY Fig.
  • Page 126 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (7) Remove the bind B M3x8 Taptite screw from the guide plate stopper and remove the left guide spring 2. (8) Remove the side regist guide from the DX feed ASSY by releasing the hook at the bottom side of the ASSY using a pair of long nose pliers.
  • Page 127 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (10) Fig. 4-31Remove the side regist roller from the DX feed ASSY and then remove the T-belt B40S2M142 and the T-belt B40S2M224. DX feed ASSY Side regist roller T-belt B40S2M224 T-belt B40S2M142 Fig. 4-32 (11) Remove the DX paper actuator and the guide actuator from the DX feed ASSY, and then remove the paper actuator spring and the guide actuator spring from the each actuator.
  • Page 128: Rear Cover

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY Rear Cover (1) Open the rear cover. (2) Release the hooks on the right and left sides of the DX rear chute to release the DX outer chute ASSY from the rear cover. (hook) Printer Rear cover R DX rear chute DX outer chute ASSY...
  • Page 129 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (4) Remove the frap 2 spring from the flap 2 and then remove the flap 2 from the DX outer chute. Flap 2 Frap 2 spring DX outer chute (hook) Fig. 4-36 (5) Remove rear cover from the printer by releasing the hooks at the right and left sides of the printer and then remove the DX rear chute from the rear cover C.
  • Page 130: Rear Cover R & L / Side Cover R & L

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY Rear Cover R & L / Side Cover R & L (1) Remove the two shoulder screws to remove the rear cover R and rear cover L from the printer. Rear cover R Printer Rear cover L Shoulder screws Fig.
  • Page 131 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY Fig. 4-39 4-24...
  • Page 132: Mp Cover Assy

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY MP Cover ASSY (1) Open the MP cover ASSY. Remove the MP paper guide 1 ASSY from the front cover by releasing two hooks and pulling slightly upward. Printer MP paper guide 1 ASSY MP cover ASSY (hook) Fig.
  • Page 133 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (4) Remove the MP cover ASSY from the printer. (hook) (hook) Printer (hook) MP cover ASSY Fig. 4-42 (5) Remove the MP side guide 2 from the MP cover and then MP side guide 3 from the MP side guide 2.
  • Page 134: Process Unit Cover Assy

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.10 Process Unit Cover ASSY (1) Release the hooks while pushing the process unit cover ASSY slightly inward to remove the cover by pulling it forward. (hook) Printer Process unit cover ASSY Fig. 4-44 (2) Remove the two cup B M3x8 Taptite screws to remove the process unit cover from the process unit cover ASSY.
  • Page 135: Laser Unit

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.11 Laser Unit (1) Loosen the cup S tite 3x6 screw to release the fan relay PCB ASSY and the harness on the fan relay PCB ASSY from the main unit. Screw, cup S tite 3x6 Fan relay PCB ASSY Main unit Fig.
  • Page 136: Fixing Unit

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY CAUTION: • Never touch the reflect mirror and lens inside the laser unit. If there is any dirt or dust on the mirror or lens, blow it off using an air gun. • Never touch the scanner window on the printer body. If there is any dirt or dust on the window, blow it off using an air gun.
  • Page 137 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (5) Remove the three bind B tite 3x10 screws to remove the FU front paper guide from the fixing unit . Fixing unit FU front paper guide Screw, bind B tite 3x10 Fig. 4-50 (6) Remove the two cup B M3x20 Taptite screws from the top of the fixing unit frame. (7) Release the thermistor harness from the hooks.
  • Page 138 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (8) Remove the FU frame upper from the FU frame lower by releasing hooks as shown in the figure below. (hook) (hook) (hook) FU frame lower FU frame upper (hook) (hook) (hook) Fig. 4-52 (9) Remove the one pan B M3x10 Taptite screw securing the halogen lamp connector plate at the drive unit side of the FU frame upper and then loosen the pan (washer) M2.6x6 screw at the other side.
  • Page 139 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY NOTE: When re-assembling the halogen heater lamp, ensure that the direction of the halogen heater lamp is correct referring to the figure above. 4-32...
  • Page 140 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY CAUTION: • Never touch the surface of the halogen heater lamp. • When securing the screw to assemble the halogen lamp connector plate, ensure you use the plastic jig as shown in the figure below to avoid damaging the edge of the halogen heater lamp.
  • Page 141 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY Never touch the surface of the heat roller. 4-34...
  • Page 142 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY NOTE: • When re-assembling the heat roller 25 HE to the FU frame upper, place the two projections at the right hand side of the roller onto the bosses on the frame as shown in the figure below.
  • Page 143 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (14) Remove the pressure roller 25 from the FU frame lower by gently levering the right hand side upwards to release it from the PR bearing and then sliding it to the right to remove it. (15) Remove the five cleaner pinch roller ASSY complete with the pick off finger cleaner spring and the thermistor cleaner spring for each from the FU frame lower by lifting it upwards until the spring releases from the cover.
  • Page 144 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (17) Remove the bind B tite 3x10 screw to remove the eject sensor PCB ASSY. (18) Disconnect the connector for the thermistor relay PCB ASSY. (19) Remove the bind B tite 3x10 screw to remove the thermistor relay PCB ASSY from the FU frame lower.
  • Page 145 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY NOTE: When re-assembling the paper eject actuator and the eject actuator spring to the FU frame lower, ensure the paper eject actuator is seated correctly in the locating channel referring to the figure below; FU frame lower Eject actuator spring Paper eject actuator Fig.
  • Page 146 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY NOTE: When re-assembling the thermistor to the FU frame upper, ensure the direction of the thermistor is correct referring to the figure below; FU frame upper Thermistor Thermistor Taptite, cup B M3x12 Fig. 4-64 (23) Remove the B 2.6x10 Taptite screw to remove the idle gear 13H. Hold slightly up the right end of the eject roller and then remove the left end of the roller from the hook first, then remove the eject roller from the FU frame upper.
  • Page 147 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (24) Remove the eject pinch roller F (8pcs.) with the eject pinch roller holder R (2pcs.) and the eject pinch roller holder L (2pcs.) from the FU frame upper, and then remove the eject pinch spring (4pcs.). Eject pinch roller F with eject pinch roller holder R Eject pinch roller F with...
  • Page 148 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 4-41...
  • Page 149 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (26) Release the harness from the hooks on the FU frame upper. Turn the frame up-side down. Remove the cup B M3x6 Taptite screw to remove the pick off finger holder plate and then remove the pick off finger using a piece of tweezers. Taptite,cup B M3x6 Pick off finger Pick off finger holder plate...
  • Page 150: Paper Pick-Up Roller Assy

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.13 Paper Pick-up Roller ASSY NOTE: Be sure to remove all the covers before removing the paper pick-up roller ASSY. (1) Place the main frame upside down. (2) Remove the bearing R from the front chute ASSY. (3) Shift the paper pick-up roller ASSY with two roller collars to the left (the bearing R side) to release from the paper pick-up roller shaft.
  • Page 151: Feed Mp Unit

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.14 Feed MP Unit (1) Turn the main frame the right way up. (2) Open the MP roller cover. (2) Remove the bearing R from the MP chute ASSY. (3) Shift the paper pick-up roller ASSY with two roller collars to the left (the bearing R side) to release from the MP paper pick-up roller shaft.
  • Page 152 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (6) Remove the separation plate ASSY. (7) Remove the two MP pressure spring 25. (8) Remove the two bind B tite 3x10 screws from the MP chute cover. (9) Release the two bosses at the both ends of the MP pressure plate ASSY using a flat screwdriver, and then remove it from the main frame.
  • Page 153: Drive Unit

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.15 Drive Unit (1) Place the printer body carefully on its left hand side so that the drive unit is at the top. (2) Remove the three cup S tite 3x6 screws securing the reversing drive frame unit. (3) Disconnect the harness connector and remove the bind M3x4 screw to remove the reversing switch solenoid from the reversing drive frame unit.
  • Page 154 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (4) Release the hook of the gear to remove the switch arm ASSY and then remove the T-belt by releasing the hook of the two gears. Switch arm ASSY (hook) Gear Gear (hook) (hook) T-belt Drive unit Fig.
  • Page 155 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (7) Remove the three tapes on the harnesses and release the harness from the hooks. (8) Remove the four cup S tite 3x6 screws from the drive sub ASSY A and remove the spring, extension P/R from the gear 60 P/R. (9) Disconnect the connectors for the main motor ASSY and the toner LED PCB unit.
  • Page 156 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (11) Remove the four cup S tite 3x6 screws and disconnect the harness to remove the main motor ASSY from the drive sub ASSY A. Screw, cup S tite 3x6 Screw, cup S tite 3x6 Drive sub ASSY A Drive sub ASSY A Fuser drive gear...
  • Page 157 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (10) Disconnect the two connectors for the solenoid relay PCB to remove the solenoid unit from the drive unit. (11) Release the two hooks and remove the solenoid ASSY 04C4 (red) and the solenoid ASSY 04C5 (black) from the unit.
  • Page 158 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY Fig. 4-80 4-51...
  • Page 159: Low-Voltage Power Supply Pcb Assy

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (16) Remove the gear 60 P/R and gear 72 MP from the conductor bearing 5, and remove the middle roller gear from the conductor bearing H. (17) Remove the two conductor bearing 5. (18) Turn the knob of the conductor bearing H as the figure shown below, and remove the conductor bearing H from the main frame L.
  • Page 160 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY Fig. 4-82 4-53...
  • Page 161: Main Pcb Assy

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.17 Main PCB ASSY (1) Remove the two pan M3x6 screws and the six cup S tite 3x6 screws from the main PCB ASSY. (2) Disconnect the four connectors for the low-voltage power supply, engine PCB, the panel PCB and the scanner unit.
  • Page 162 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY When re-assembling the fan motor and the fan motor 60, fit the both motors with the labeled surface facing the printer. 4-55...
  • Page 163: Base Plate

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.19 Base Plate (1) Turn the main frame upside down. (2) Remove the five bind B M4x10 Taptie screws and four cup S tite 3x6 screws from the base plate. (3) Slide the base plate to the rear of the printer to remove it. Taptite, bind B M4x10 Screw, cup S tite 3x6 Base plate...
  • Page 164 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (2) Remove the two bind B M4x10 Taptite screws, one from the high-voltage PS PCB ASSY and the other from the engine PCB ASSY. (3) Shift the engine PCB ASSY slightly and remove the central connector, which connects the engine PCB ASSY, and the high-voltage PS PCB ASSY.
  • Page 165: Dx Sensor Pcb Assy

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.21 DX Sensor PCB ASSY NOTE: Be sure to disconnect the DX sensor connector on the engine PCB before removing the DX sensor PCB ASSY. (1) Remove the two cup S tite 3x6 screws to remove the DX guide rail L with DX sensor PCB ASSY from the main frame.
  • Page 166: Toner Sensor Pcb Unit (Light Reception)

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.22 Toner Sensor PCB Unit (Light Reception) NOTE: Be sure to disconnect the toner sensor (light reception) connector on the engine PCB before removing the toner sensor PCB ASSY (light reception). (1) Remove the harness from the hooks on the fan duct. (2) Release the three hooks, and then lift up slightly and slide the fan duct to remove it.
  • Page 167 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY Fig. 4-91 4-60...
  • Page 168: Paper Feed Roller Assy

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.24 Paper Feed Roller ASSY NOTE: Be sure to remove all the covers and the gear 21 before removing the paper feed roller ASSY. (1) Unhook the catch to remove the bearing 5 from the front chute ASSY. (2) Remove the paper feed roller ASSY from the front chute ASSY by sliding to the left, then lifting upward.
  • Page 169 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY Fig. 4-93 4-62...
  • Page 170 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (3) Remove the paper pick-up roller shaft and the first feed roller shaft from the front chute ASSY. (4) Remove the four bind B M4x10 Taptite screws to remove the front chute ASSY. CA actuator PE actuator Taptite, bind B M4x10 Paper pick-up roller shaft...
  • Page 171: Exit Roller Unit

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.26 Exit Roller Unit NOTE: Be sure to disconnect all the connectors on the fan relay PCB before removing the exit roller unit. (1) Remove the two shoulder screws to remove the exit roller unit from the printer. Shoulder screws Exit roller unit Fig.
  • Page 172 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY Fig. 4-97 4-65...
  • Page 173 CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (5) Remove the fan motor 60B unit from the exit roller holder. Fan motor 60B unit Exit roller holder Fig. 4-98 4-66...
  • Page 174: 3.27 Harness Winding Form

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.27 Harness Winding Form 4-67...
  • Page 175: Packing

    CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY PACKING AC Cords Accessory Bag Accessory Carton Drum Unit (with Toner Cartridge included) Printer Carton Fig. 4-99 4-68...
  • Page 176: Chapter 5 Periodic Maintenance

    HL-1850/1870N SERVICE MANUAL CHAPTER 5 PERIODIC MAINTENANCE To avoid creating secondary problems by mishandling, follow the warnings below during maintenance work. WARNING (1) Always turn off the power switch and unplug the power cord from the power outlet before accessing any parts inside the printer.
  • Page 177: Toner Cartridge

    (8) Close the front cover. CAUTION: • For best performance, use only genuine Brother toner. The product should only be used in a clean, dust-free environment with adequate ventilation.. • Only unpack a drum unit immediately before you need to install it into the printer. If an unpacked drum unit is subjected to excessive direct sunlight or room light, the unit may be damaged.
  • Page 178 HL-1850/1870N SERVICE MANUAL NOTE: There are many factors that determine the actual toner life, such as temperature, humidity, type of paper that you use, the number of pages per print job, etc. <Replacement Procedure> (1) Press the cover release button and then open the front cover.
  • Page 179 • If an unpacked drum unit is subjected to excessive direct sunlight or room light, the unit may be damaged. • Use a Brother genuine toner cartridge which is specially formulated to ensure top print quality. • Printing with a 3rd party toner or toner cartridge may reduce not only the printing quality but also the quality and life of the printer itself.
  • Page 180: Periodical Replacement Parts

    HL-1850/1870N SERVICE MANUAL PERIODICAL REPLACEMENT PARTS Periodical replacement parts are the parts to be replaced periodically to maintain product quality. These parts would affect the product quality greatly if they lost their function even if they do not appear to be damaged or there is no change in their appearance.) The periodical replacement parts listed below should be replaced at the service center referring to the service life.
  • Page 181: Periodical Cleaning

    CHAPTER 5 PERIODIC MAINTENANCE PERIODICAL CLEANING Clean the following parts periodically to avoid any printer problems or print image defects. CAUTION: While drum unit and scanner window cleaning basically can be implemented by the end user, the electrical terminals inside the printer and on the drum unit should be cleaned by a service technician.
  • Page 182: Cleaning The Scanner Window

    HL-1850/1870N SERVICE MANUAL Clean the primary corona wire inside the drum unit by gently sliding the blue tab from right to left several times. Return the tab to the home position before re-install the drum unit assembly. Home position  Fig.
  • Page 183: Cleaning The Electrical Terminals

    HL-1850/1870N SERVICE MANUAL Re-install the drum unit assembly into the printer. Close the front cover. Plug in the power cord, and then turn on the power switch. CAUTION: • Handle the drum unit carefully since it contains toner. If toner scatters and your hands or cloths get dirty, immediately wipe or wash it off with cold water.
  • Page 184: Mtbf / Mttr

    CHAPTER 5 PERIODIC MAINTENANCE MTBF / MTTR The meantime between failure (MTBF and the meantime to repair (MTTR) for this printer are as follows; MTBF: Up to 4,000 hours MTTR: Average 30 minutes except the periodical maintenance parts (the Paper Feeding Kit) and the printer control boards whose MTTR is average 5 minutes.
  • Page 185: Chapter 6 Troubleshooting

    HL-1850/1870N SERVICE MANUAL CHAPTER 6 TROUBLESHOOTING INTRODUCTION Initial Check (1) Operating environment Check if : • The source voltage stays within ±10% from the rated voltage shown on the rating plate. • The printer is installed on a solid, level surface.
  • Page 186: Warnings For Maintenance Work

    CHAPTER 6 TROUBLESHOOTING (4) Others Condensation: When the printer is moved from a cold room into a warm room in cold weather, condensation may occur inside the printer, causing various problems as listed below: • Condensation on the optical surfaces such as the scanning mirror, lenses, the reflection mirror and the protection glass may cause the print image to be light.
  • Page 188: Operator Calls & Service Calls

    CHAPTER 6 TROUBLESHOOTING OPERATOR CALLS & SERVICE CALLS Operator Calls An ‘operator call’ which the printer indicates on the LCD display is user recoverable. Identify the error from the table below and take the corrective action described for each indication to correct it.
  • Page 189 HL-1850/1870N SERVICE MANUAL Error Message Remedy Reduce the resolution, or add the optional memory. PRINT OVERRUN (1) Press the Go switch to print the data remaining in the printer. (2) Reduce the complexity of the document. (3) Expand the printer memory by adding a commercially available DIMM.
  • Page 190: Service Calls

    CHAPTER 6 TROUBLESHOOTING Service Calls When each of the following messages appears alternately on the LCD, a user unrecoverable error may have occurred. Instruct the user to turn off the power switch, wait 5 seconds and then turn it on again. If the error is not cleared and the same service call appears, identify the error from the table on the next page and take the corrective action described for each indication to correct it.
  • Page 191 HL-1850/1870N SERVICE MANUAL Error Messages Meaning Remedy Turn off the printer. Wait a few seconds, ERROR S01 then turn it on again. If still remains, replace the main PCB. Instruction access error Turn off the printer. Wait a few seconds, ERROR S02 then turn it on again.
  • Page 192 CHAPTER 6 TROUBLESHOOTING error’ in this chapter.
  • Page 193 HL-1850/1870N SERVICE MANUAL PR2001022 Error Messages Meaning Remedy Malfunction of fuser Turn off the printer. Wait a few seconds, ERROR E49 detected by hard wear. and then turn it on again. Refer to ‘Fuser failure’ in this chapter. Malfunction of fuser Turn off the printer.
  • Page 194: Paper Problems

    CHAPTER 6 TROUBLESHOOTING and then turn it on again. PAPER PROBLEMS When any paper related problem occurs, ensure that the paper used meets the recommended paper specifications referring to subsection 3.5 ‘Paper’ in CHAPTER Paper Loading Problems Problem Remedy The printer does not (1) If there is paper in the paper cassette, make sure it is straight.
  • Page 195: Paper Jams

    HL-1850/1870N SERVICE MANUAL Paper Jams • If paper jams in the printer, it will stop printing and display the following messages on the LCD display. JAM INSIDE JAM TRAY1 JAM REAR JAM TRAY2 JAM MP TRAY JAM DUPLEX PAPER JAM •...
  • Page 196: Clearing Jammed Paper

    CHAPTER 6 TROUBLESHOOTING 3.2.1 Clearing jammed paper Clear the jammed paper following the procedures below; JAM TRAY 1 (1) Pull the paper cassette completely out of the printer. Fig. 6-2 (2) Pull the jammed paper out of the printer. (3) Install the paper cassette into the printer.
  • Page 197 HL-1850/1870N SERVICE MANUAL (2) Using both hands, pull the jammed paper out of the printer. (3) Install the lower paper cassette into the printer. Fig. 6-5 JAM MP TRAY (1) Remove the jammed paper from the multi-purpose tray. Fig. 6-6 (2) Reset all the paper into the multi- purpose tray correctly.
  • Page 198 CHAPTER 6 TROUBLESHOOTING (3) Pull the jammed paper up and out of the printer.  Fig. 6-9 (4) Install the drum unit assembly and paper cassette into the printer. Close the front cover. WARNING The fixing roller is extremely hot during operation. Remove the paper carefully. CAUTION: •...
  • Page 199: Paper Jams

    HL-1850/1870N SERVICE MANUAL CAUTION: • It is recommended to put the drum unit assembly on a piece of disposable paper or cloth so you don’t accidentally spill or scatter toner. • To prevent damage to the print caused by static electricity, do not touch the electrodes shown below.
  • Page 200 CHAPTER 6 TROUBLESHOOTING 6-16...
  • Page 201 HL-1850/1870N SERVICE MANUAL (5) Open the jam clear cover. Pull the jammed paper out of the fuser unit. Jam clear cover Fig. 6-14 (6) Close the jam clear cover. Close the face up output tray (rear cover). Fig. 6-15 (7) Install the drum unit assembly into the printer.
  • Page 202 CHAPTER 6 TROUBLESHOOTING (2) Pull the jammed paper out of the fuser unit. Fig. 6-18 (3) Close the face up output tray (rear cover). If the paper jam can not be cleared, go to the next step. Fig. 6-19 (4) Pull the duplex tray and paper cassette out of the printer.
  • Page 203 HL-1850/1870N SERVICE MANUAL 6-19...
  • Page 204 CHAPTER 6 TROUBLESHOOTING NOTE: • The JAM DUPLEX message appears if you remove a sheet of paper from the face down output tray after only one side has printed. • The paper sized you can use for the duplex printing function are A4, Letter and Legal. •...
  • Page 205 HL-1850/1870N SERVICE MANUAL (4) Pull the drum unit assembly out of the printer. Pull the jammed paper up and out of the printer. Fig. 6-26 If the paper jam can be cleared, go to (8). (5) Open the face up output tray (rear cover).
  • Page 206: Causes & Countermeasures

    CHAPTER 6 TROUBLESHOOTING 3.2.2 Causes & countermeasures The causes for paper jam problems vary depending on the location of the paper jam. When a paper jam occurs inside the printer, you have to find the location of the paper jam first, remove the jammed paper and then take the appropriate countermeasure referring to the table below;...
  • Page 207: Paper Feeding Problems

    HL-1850/1870N SERVICE MANUAL Paper Feeding Problems Even if the paper is printed and ejected without any problems such as paper jams, paper feeding problems below may appear. Users can clear these problems by following the ‘User Check’ items for each problem. Even if the same problem occurs again, follow the procedures in the table below.
  • Page 208 CHAPTER 6 TROUBLESHOOTING 6-24...
  • Page 209 HL-1850/1870N SERVICE MANUAL Curl or Wave User Check (1) Check the paper used meets the recommended paper specifications. Both high temperature and humidity will cause paper to curl. (2) If the printer is used infrequently, the paper may have sat for too long in the paper cassette. Turn over the stack of paper in the paper cassette.
  • Page 210: Software Setting Problems

    CHAPTER 6 TROUBLESHOOTING SOFTWARE SETTING PROBLEMS The printer may not print the data correctly if there are incorrect software settings. “There was an error writing to LPT1: (or BRUSB) for the printer” error message appears. User Check (1) Check that the printer cable is not damaged or broken. Check also that the cable is connected to the correct interface connectors of both the printer and PC.
  • Page 211 HL-1850/1870N SERVICE MANUAL Unable to print from application software under DOS. User Check (1) Check that the DOS application software interface settings match that of your printer. (2) Check if the printer has any printer alarms active. (3) Check if the appropriate printer is selected in your application software.
  • Page 212 Check that the USB cable Volumes tab? used is the shielded twisted • Product ID: 11 ($6) pair type and 5 m or less. • Vender: Brother International Try to connect the printer and Corporation (or 0x4f9) PC with the USB cable directly.
  • Page 213: Malfunctions

    HL-1850/1870N SERVICE MANUAL MALFUNCTIONS When taking countermeasures for malfunctions as described in this section, check connectors for contact failure before measuring the voltage at the specified connector pins. No AC power supplied Possible cause Step Check Result Remedy Supply voltage...
  • Page 214 CHAPTER 6 TROUBLESHOOTING Main motor does not rotate Possible cause Step Check Result Remedy Failure of Is the connection of connector Reconnect the connector. connector P9 on the engine PCB correct? Main motor Is the problem solved by Replace the main motor. replacing the main motor? Engine PCB Is the problem solved by...
  • Page 215 HL-1850/1870N SERVICE MANUAL Insufficient output from high-voltage power supply unit Possible cause Step Check Result Remedy High-voltage Do any of the terminals on the Clean the terminals. contact high-voltage contacts have dirt or contact burns? High-voltage Check the connections of the...
  • Page 216 CHAPTER 6 TROUBLESHOOTING Scanner failure Possible cause Step Check Result Remedy Harness Is the connection of the Reconnect the connector connection scanner motor connector securely. failure the engine PCB secure? Power supply Is the voltage between pins 1 Check if +24V DC is supplied input (+24V DC) and 2 (GND) of between pins...
  • Page 217 ‘INSPECTION MODE’ in this Chapter? Software bug Does this problem appear Inform the Brother office of when printing specific data or the used specific data, printer printing under a specific condition and system environment? environment.
  • Page 218 CHAPTER 6 TROUBLESHOOTING M-13 PCI BUS error Possible cause Step Check Result Remedy Harness Is the connection between Reconnect the connectors connection connector P21 on the main securely. failure PCB and connector P1 on the network board secure? Network board Is the problem solved by Replace the network board.
  • Page 219: Image Defects

    HL-1850/1870N SERVICE MANUAL IMAGE DEFECTS Image Defect Examples I-5 Dirt on back of paper I-1 Light I-2 Dark I-2 Dark I-3 Completely blank I-4 All black I-6 Black vertical I-6 Black vertical I-7 Black horizontal I-8 Black vertical I-9 White vertical...
  • Page 220: Troubleshooting Image Defect

    CHAPTER 6 TROUBLESHOOTING Troubleshooting Image Defect Several types of the image defects can be cleared by end users. For those defects, instruct the user to check the ‘User Check’ items described in each table. Even if the same image defect appears, the following procedures should be followed in the event of specific image defects.
  • Page 221 HL-1850/1870N SERVICE MANUAL Dark User Check (1) Check the paper used meets the recommended paper specifications. (2) Check the printer’s environment. High temperature and high humidity conditions can increase the amount of background shading. (3) Clean the corona wire with the wire cleaner.
  • Page 222 CHAPTER 6 TROUBLESHOOTING Completely blank Ground Possible cause Step Check Result Remedy contacts Developing bias Are the developing bias Clean the electrodes contact failure contacts between the printer at both sides. body and drum unit dirty? Drum unit Are the drum shaft and drum Clean the shaft and electrode of the printer body the electrode.
  • Page 223 HL-1850/1870N SERVICE MANUAL All black User Check (1) Clean the corona wire of the drum unit. (2) The drum unit may be damaged. Install a new drum unit. Ground Possible cause Step Check Result Remedy contacts Corona failure Is the corona wire dirty? Clean the corona wire with the wire cleaner.
  • Page 224 CHAPTER 6 TROUBLESHOOTING Dirt on the back of paper Possible cause Step Check Result Remedy Clean the pressure roller Fixing unit dirty Is the pressure roller dirty? referring to the following Is any other area in the printer procedure. dirty? Dirt in the drum Is the transfer roller dirty? Replace the drum unit...
  • Page 225 HL-1850/1870N SERVICE MANUAL Black and blurred vertical streaks User Check (1) Clean the corona wire in the drum unit. (2) Check that the corona wire cleaner is at the home position. (3) Check that the toner cartridge is not empty.
  • Page 226 CHAPTER 6 TROUBLESHOOTING Black and blurred horizontal stripes User Check (1) The drum unit may be damaged. Install a new drum unit. (2) Check the paper used meets the recommended paper specifications. (3) Clean the printer interior and the corona wire in the drum unit. Ground Possible cause Step...
  • Page 227 HL-1850/1870N SERVICE MANUAL White vertical streaks User Check (1) Try to wipe the scanner window with a soft cloth. (2) The toner cartridge may be damaged. Install a new toner cartridge. (3) Check the printer’s environment. High temperature and high humidity conditions can cause this problem.
  • Page 228 CHAPTER 6 TROUBLESHOOTING I-11 Faulty registration Possible cause Step Check Result Remedy Excessive paper Is the paper loaded in the Instruct the user to keep paper load paper cassette more than loads below 27mm in depth. 27mm high? Print paper Is the specified weight of the Recommend to use the recommended paper being...
  • Page 229 HL-1850/1870N SERVICE MANUAL I-13 Image distortion Possible cause Step Check Result Remedy Laser unit Is the laser unit secured to the Secure the unit correctly and installation frame incorrectly? tighten the screws. (Check if there is any play.) Scanner LD Is the laser diode or the Replace the laser unit.
  • Page 230 CHAPTER 6 TROUBLESHOOTING I-15 White spots User Check (1) If the problem is not solved after printing a few pages, the drum unit may have glue from label stock on the photosensitive drum surface. Refer to Step 1 in the table below and NOTE in the next page.
  • Page 231 HL-1850/1870N SERVICE MANUAL NOTE: Clean the drum unit as follows: (1) Remove the toner cartridge from the drum unit. Place the printing samples in front of the drum unit, and find the exact position of the image defect. Drum unit...
  • Page 232 CHAPTER 6 TROUBLESHOOTING I-16 Black spots User Check (1) If the problem is not solved after printing a few pages, the drum unit may have glue from label stock on the photosensitive drum surface. Refer to Step 1 in the table below and NOTE in the previous page.
  • Page 233 HL-1850/1870N SERVICE MANUAL I-17 Black band Ground Possible cause Step Check Result Remedy contacts Corona failure Is the wire cleaner at its home Return the wire position? cleaner to its home position. Corona failure Is the corona wire dirty? 1) Clean the corona wire.
  • Page 234 CHAPTER 6 TROUBLESHOOTING I-18 Gray background Possible cause Step Check Result Remedy Print paper Does the paper being used Recommend to use the meet the paper specification specified types of paper. (weight, etc.). Recommend to change to freshly unpacked paper. Toner sensing Does the “Ready”...
  • Page 235 HL-1850/1870N SERVICE MANUAL I-19 Hollow print User Check (1) Check the paper used meets the recommended paper specifications. (2) Select the ‘Thick paper mode’ in the printer driver, or use thinner paper than you are currently using. (3) Check the printer’s environment, conditions such as high humidity may cause this situation to occur.
  • Page 236 CHAPTER 6 TROUBLESHOOTING I-21 Horizontal lines Ground Possible cause Step Check Result Remedy contacts Paper cassette Are the ground contacts on the Clean the contacts. contacts back side of the paper cassette connecting correctly? 6-52...
  • Page 237 HL-1850/1870N SERVICE MANUAL I-22 Light rain Ground Remedy Possible cause Step Check Result contact Drum unit failure Is the problem solved after Replace the drum replacing the drum unit? unit. Drum Is the contact between the Clean contact connection drum unit and printer body...
  • Page 238 CHAPTER 6 TROUBLESHOOTING I-24 Toner specks User Check (1) Check the paper used meets the recommended paper specifications. A rough surfaced paper may cause the problem. (2) The toner cartridge may be damaged. Install a new toner cartridge. (3) The drum unit may be damaged, or may be nearly at the end of life. Install a new drum unit.
  • Page 239: Location Of Grounding Contacts

    HL-1850/1870N SERVICE MANUAL Location of Grounding Contacts 6.3.1 Drum unit (2) Wire cleaner Drum Unit (5) Grid (8) Cleaner (4) Development roller (3) Charge (1) Photosensitive drum (6) Transfer roller Fig. 6-34 6.3.2 Printer body & Paper cassette (1) Photosensitive drum...
  • Page 240: Incorrect Printout

    CHAPTER 6 TROUBLESHOOTING INCORRECT PRINTOUT When the data is not printed correctly as it is seen on the PC screen, follow the procedures below in the event of a specific error. The printer prints unexpectedly or it prints garbage. User Check (1) Check if the printer cable is not too long.
  • Page 241 HL-1850/1870N SERVICE MANUAL Unable to print full pages of a document with the “PRINT OVERRUN” message. User Check (1) Press the Go switch on the control panel to print the data remaining in the printer. (2) If this does not clear the error, reduce the complexity of your document or reduce the printer resolution.
  • Page 242 Remember that the printer emulates widely used printer selections: HP LaserJet, Brother BR-Script Level 3, Epson FX-850, IBM Proprinter XL Try setting the printer into HP emulation and then select the HP LaserJet 6P printer in the application software.
  • Page 243: Network Problem

    (make sure that you have entered the print server name). If you can see Print Server Status and Control in the menu, then the Brother print server is visible to the network, proceed to subsection 8.10 ‘Novell NetWare Troubleshooting’.
  • Page 244: Intermittent Problem

    (a process known as filtering); therefore, such a bridge must be configured to allow Brother print server addresses. Likewise, a router can be set up to pass only certain protocols, so be sure that the desired protocol can be passed through to the print server.
  • Page 245: Tcp/Ip Troubleshooting

    HL-1850/1870N SERVICE MANUAL TCP/IP Troubleshooting If you are using TCP/IP and cannot print to the print server and you have checked the hardware and network as described in the previous steps, then check the following: NOTE: It is always a good idea to try the following in order to eliminate the possibility of setup errors.
  • Page 246: Windows Nt/Lan Server (Tcp/Ip) Troubleshooting

    If you are having trouble printing on a Windows 95/98/Me Peer to Peer network (LPR method), check the following: (1) Make sure that the Brother LPR Port driver is correctly installed and configured according to the Windows 95/98/Me Peer to Peer chapters in the Network User’s Guide.
  • Page 247: Windows 95/98/Me (Or Later) Peer To Peer (Hp Jetadmin Compatible Method) Troubleshooting

    If you are having trouble printing on a Windows 95/98/Me/NT 4.0/2000 (or later) Peer to Peer network (NetBIOS), check the following: (1) Make sure that the Brother NetBIOS Port driver is securely installed and configured according to the Windows 95/98/Me/NT 4.0/2000 Peer to Peer (NetBIOS) chapters. You may find that during the installation of the port driver, the screen that prompts you for a Port name is not displayed.
  • Page 248: Novell Netware Troubleshooting

    If you cannot print from NetWare and you have checked the hardware and network as described in the previous steps, first verify that the Brother print server is attached to the server queue by going to PCONSOLE, selecting PRINT QUEUE INFORMATION, and then CURRENTLY ATTACHED SERVERS.
  • Page 249: Apple Tcp/Ip Printing (System 8.6 Or Later)

    HL-1850/1870N SERVICE MANUAL (5) Verify that you have selected the correct AppleTalk zone. Because the print server gets its zone information from router broadcasts, it may not be in the zone you expect, and will therefore not show up in the Chooser. If this is the case, you may need to force the zone name with the SET APPLETALK ZONE command described in Appendix A in the Technical Reference Guide or using BRAdmin Professional.
  • Page 250: Inspection Mode

    CHAPTER 6 TROUBLESHOOTING INSPECTION MODE Entering Inspection Mode Select the inspection mode you want to use following the steps below; (1) Turn off the power switch of the printer (2) Turn on the power switch while holding down the Go switch and the Set switch. (3) Release the both switches when the message “GO TEST MODE”...
  • Page 251: Sensor Check Mode

    HL-1850/1870N SERVICE MANUAL Sensor Check Mode The sensor check mode is used to check if the sensors in the printer are functioning correctly. In the process of this inspection, the Data LED and the control panel switches are also checked.
  • Page 252 CHAPTER 6 TROUBLESHOOTING Display Name of Sensor Status ON: The front cover is open. Cover sensor Black square OFF: The front cover is closed. ON: The toner cartridge is installed. Toner sensor Black square OFF: No toner cartridge is installed. ON: No paper cassette is installed.
  • Page 253 HL-1850/1870N SERVICE MANUAL 6-69...
  • Page 254: Chapter 7 Hidden Functions

    CHAPTER 7 HIDDEN FUNCTIONS ENTERING HIDDEN FUNCTION MENU MODES HL-1850/1870N has 3 entrances into the hidden function menu; Power on and press the Go switch and the Set switch. (Professional Menu mode) See section 2. ‘PROFESSIONAL MENU MODE’ in this Chapter.
  • Page 255: Professional Menu Mode

    CHAPTER 7 HIDDEN FUNCTIONS PROFESSIONAL MENU MODE The Professional Menu mode enables to customize various functions for specific users and may be opened to users if necessary. Enabling and Disabling Professional Menu Mode Entering the Professional Menu Mode Turn the machine on. Press the Go switch and Set switch together to enter the Professional Menu mode.
  • Page 256 HL-1850/1870N SERVICE MANUAL Function Table The following printer settings and function will be available with this operation. Title & Subtitle Item to be Set Description Feeds paper automatically when TRAY SETTING PAPER IN=CONT* printing using the manual feed (MANUAL FEED) function.
  • Page 257 CHAPTER 7 HIDDEN FUNCTIONS Enables and disables to select ISR FONT SELECT ISRFONT=DISABLE* Hebrew font. ISRFONT=ENABLE Enables and disable the built-in BRO FONT SELECT BROBITM=DISABLE* 10/12 pitch Brougham bitmap BROBITM=ENABLE font.
  • Page 258 HL-1850/1870N SERVICE MANUAL Title & Subtitle Item to be Set Description FONT SELECT The priority of selection for 300DPI PRIORITY 3B PRIO=LOW* 300dpi bitmap fonts are standard (=low). The priority of selection for 3B PRIO=HIGH 300dpi bitmap fonts are higher than scalable font.
  • Page 259 CHAPTER 7 HIDDEN FUNCTIONS Tests DRAM data. DRAM CHECK START START DRAM TEST...
  • Page 260 HL-1850/1870N SERVICE MANUAL Title & Subtitle Item to be Set Description Enables and disables automatic AUTO HRC ON/OFF AUTO HRC=OFF* HRC control. AUTO HRC=ON Adds and removes “DEMO DEMO PAGE ON/OFF DEMO PAGE=ON* PAGE” into the user menu. DEMO PAGE=OFF...
  • Page 261 CHAPTER 7 HIDDEN FUNCTIONS Title & Subtitle Item to be Set Description Does not reduce the resolution PS300RESO PS300RESO=NO* automatically. Reduces the resolution to PS300RESO=IF 2M 300dpi when the total memory is 2Mbytes. Reduces the resolution to PS300RESO=FORCE 300dpi. OFF: 1 page is fixed for the COPY PAGES COPY PAGES=ON* copy page number.
  • Page 262 HL-1850/1870N SERVICE MANUAL Enables to print PSPureBinary APPLEUSBPS BINARY=OFF* data via MacUSB. BINARY=ON Select print by simplex or duplex DX 1JOB1PAGE SEL 1JOB1PAGE=SX* when certain JOB which has 1JOB1PAGE=DX only 1 page was sent. Default is simplex. Determine PS font cache to...
  • Page 263: Function Table

    CHAPTER 7 HIDDEN FUNCTIONS PR2001036 SERVICE MENU MODE By enabling the Service Menu mode provides, you will get various printer information. This mode is not open to users. Entering the Service Menu Mode Turn the machine on. While holding down the Go switch, press the + switch once and then the Set switch until the menu “-- SERVICE MENU --“...
  • Page 264 HL-1850/1870N SERVICE MANUAL Displays the number of pages when printing A5 PAGE A5 size paper. Displays the number of pages when printing A6 PAGE A6 size paper. Title Subtitle Description Displays the number of pages when printing SERVICE INFO B6 PAGE B6 size paper.
  • Page 265 CHAPTER 7 HIDDEN FUNCTIONS Title Subtitle Description MODIFY COUNT REMAIN LIFE Modify the drum unit remaining life counters. DRUM UNIT Modify the PF kit remaining life counters. PF KIT 1 PF KIT 2 Modify the fixing unit remaining life counters. FUSER UNIT Modify the laser unit remaining life counters.
  • Page 266: Other Hidden Function Menus

    CHAPTER 7 HIDDEN FUNCTIONS PR2001022 OTHER HIDDEN FUNCTION MENUS Hidden Function Menus Enabled by Pressing Switch(es) When Turning the Machine on The following settings and function will be available by holding down the specified switch(es) while turning the machine on. Switch(es) Display Description...
  • Page 268: Connection Diagram, Hl-1850/1870N

    Appendix 1. Connection Diagram, HL-1850/1870N A - 1...
  • Page 269: Main Pcb Circuit Diagram, Hl-1850/1870N (1/6

    Appendix 2. Main PCB Circuit Diagram, HL-1850/1870N (1/6) CODE LJ8453001 NAME B512078CIR (1/6) A - 2...
  • Page 270: Main Pcb Circuit Diagram, Hl-1850/1870N (2/6

    Appendix 3. Main PCB Circuit Diagram, HL-1850/1870N (2/6) CODE LJ8453001 NAME B512078CIR (2/6) A - 3...
  • Page 271: Main Pcb Circuit Diagram, Hl-1850/1870N (3/6

    Appendix 4. Main PCB Circuit Diagram, HL-1850/1870N (3/6) CODE LJ8453001 NAME B512078CIR (3/6) A - 4...
  • Page 272: Main Pcb Circuit Diagram, Hl-1850/1870N (4/6

    Appendix 5. Main PCB Circuit Diagram, HL-1850/1870N (4/6) CODE LJ8453001 NAME B512078CIR (4/6) A - 5...
  • Page 273: Main Pcb Circuit Diagram, Hl-1850/1870N (5/6

    Appendix 6. Main PCB Circuit Diagram, HL-1850/1870N (5/6) CODE LJ8453001 NAME B512078CIR (5/6) A - 6...
  • Page 274: Main Pcb Circuit Diagram, Hl-1850/1870N (6/6

    Appendix 7. Main PCB Circuit Diagram, HL-1850/1870N (6/6) CODE LJ8453001 NAME B512078CIR (6/6) A - 7...
  • Page 275: Engine Pcb Circuit Diagram, Hl-1850/1870N (1/2

    Appendix 8. Engine PCB Circuit Diagram, HL-1850/1870N (1/2) Red 5 Pin PH Right Angle Black 6 Pin PH Right Angle Straight White 2 Pin PH Right Angle White 3 Pin PH Right Angle White 5 Pin PH Right Angle White 4 Pin PH...
  • Page 276: Engine Pcb Circuit Diagram, Hl-1850/1870N (2/2

    Appendix 9. Engine PCB Circuit Diagram, HL-1850/1870N (2/2) Straight White 9 Pin PH Red 9 Pin PH Right Angle Straight Black 5 Pin PH CODE LJ8439001 NAME B512079CIR (2/2) A - 9...
  • Page 277: Network Board Pcb Circuit Diagram, Hl-1850/1870N

    Appendix 10. Network Board PCB Circuit Diagram, HL-1850/1870N CODE LJ8439001 NAME B512058CIR A - 10...
  • Page 278: Low-Voltage Power Supply Pcb Circuit Diagram (100V

    Appendix 11. Low-voltage Power Supply PCB Circuit Diagram (100V) Low-voltage PS Circuit NAME (100V) A - 11...
  • Page 279: Low-Voltage Power Supply Pcb Circuit Diagram (200V)

    Appendix 12. Low-voltage Power Supply PCB Circuit Diagram (200V) Low-voltage PS Circuit NAME (200V) A - 12...
  • Page 280: High-Voltage Power Supply Pcb Circuit Diagram

    Appendix 13. High-voltage Power Supply PCB Circuit Diagram NAME High-voltage PS Circuit A - 13...
  • Page 281: Serial No. Descriptions

    December < ID for year > 2002 2003 < ID for factory > Kariya Plant Mie Brother BIUK Buji Nan Ling Factory (1) Printer: Printed on the label attached on the rear of the main body <MODEL NO.> <Example> < SERIAL NO. >...
  • Page 282 APPENDIX (4) Toner cartridge: Imprinted on the aluminum bag 2 A 3 0 YEAR MONTH DATE FACTORY ID NO. Printed on the bar code label attached on the toner cartridge CARTRIDGE M 9 9 A 6 0 0 1 9 9 A PRODUCTION INFO.
  • Page 283: Diameter / Circumference Of Rollers

    APPENDIX APPENDIX 15. DIAMETER / CIRCUMFERENCE OF ROLLERS The diameter and circumference of each roller are listed below; Parts Name Diameter (Circumference) φ 13.8 mm (43.3 mm) First Paper Feed Roller Paper Feed Roller φ 14.0 mm (44.0 mm) φ 15.20 mm (47.7 mm) Transfer Roller φ...
  • Page 284: Print Speeds With Various Settings

    APPENDIX 16. PRINT SPEEDS WITH VARIOUS SETTINGS Print speed of the HL-1850/1870N printers is up to 18/19 ppm when loading A4 or Letter size paper from the paper cassette in the Regular mode. Actual print speed varies depending on the media type or paper size as shown in the tables below;...
  • Page 285: How To Know Drum Unit Life & Page Counter

    APPENDIX APPENDIX 17. HOW TO KNOW DRUM UNIT LIFE & PAGE COUNTER If you want to know the drum unit life or the number of printed pages, you should print out the Print Configuration page. Printing out the Print Configuration Page (1) Press the Set switch three times.
  • Page 286 APPENDIX How to Read the Drum Unit Life The drum unit life is shown by the bar at the bottom of Print Configuration or Test Print as follows; • It initially indicates 100% and gradually decreases. • It indicates 0% when the “CHANGE DRUM SOON” message appears on the LCD display on the control panel.
  • Page 287 APPENDIX How to Read the Page Counter The page counter is shown at the right upper corner in Print Configuration. It is also shown in the upper line on the right below the drum life bar and indicates the number of printed pages in units of 1 and 1,000.
  • Page 288 APPENDIX How to Read the Maintenance Information The maintenance information such as the frequency of consumable parts replacement or paper jam can be found from the 17-digit number shown in the lower line on the right below the drum unit life bar. NOTE: The 17-digit number is also shown in the Printer Information dialog box which is one of the self- diagnostics tools.
  • Page 289 APPENDIX If the printer is connected to a parallel port, you can take the following steps; (1) Open the Maintenance Information utility, then select ‘Get the Information’ in the menu. (2) Select the LPT port you are using and click the OK button.
  • Page 290: How To Use The Self-Diagnostics Tools

    APPENDIX APPENDIX 18. HOW TO USE THE SELF-DIAGNOSTICS TOOLS Three self-diagnostics tools below are automatically installed when the printer driver is installed; 1) Troubleshooting for Printer won’t print 2) Diagnostics 3) Printer Information The following sections describe the details on each tool. Troubleshooting for Printer won’t print This tool instructs you how to clear the problem such as ‘The printer can’t print’...
  • Page 291 APPENDIX Diagnostics This tool helps you to report your PC environment to investigate the cause of problem such as ‘Printer won’t print’ or ‘Printer prints garbage or incorrect fonts’. Before using this tool, however, you have to check if you can clear the problem using the ‘Troubleshooting for printer won’t print’...
  • Page 292 APPENDIX (3) If you click the OK button in Step 2, the dialog box below appears. Fig. A-11 (4) Check the result that the printer reported and click the A, B or C button depending on the result. (5) The created log file is shown on the PC screen. (The software will ask whether you wish to print the log file or not.) Send the log file created with this tool to investigate the problem to the authorized service center.
  • Page 293: Printer Information

    APPENDIX Printer Information The drum unit life or page counter is printed on Print Configuration in some countries as described in APPENDIX 17 ‘HOW TO KNOW DRUM UNIT LIFE & PAGE COUNTER’. This tool also shows the printer information such as printer version or page counter for all models only when the printer is connected to a parallel port.
  • Page 294: Nvram Default Value

    APPENDIX APPENDIX 19. NVRAM DEFAULT VALUE The default values for the main items to be set in NVRAM are as follows; Items Descriptions Timing of Drum LED ON 16,000 page (Counted from the drum unit life.) Development switching The developing bias is switched from 400V to 300V when timing 7,000 pages are printed.
  • Page 295: Paper Cassette Information (For Europe Only

    Cutting position Fig. A- 14 (3) If the optional LT-500 Lower Tray Unit is installed onto the HL-1850/1870N printer, it is necessary to exchange the cassette supplied with the LT-500 Unit with the upper cassette already fitted into the printer. Install the cassette originally fitted in the printer into the LT- 500 Unit.
  • Page 296: Guidelines For Lead Free Solder (Main Pcb Assy

    Relatively poor wettability, rough surface (bumps are likely to be formed), and solder dragging Poor solder elevation Poor thermal conductivity and heat resistant (difficult to melt) 2. Metal composition & wire solder The metal composition of lead-free solder allowed for use on PCBs for Brother's products is following. Compositon Manufacturer Origin...
  • Page 297 APPENDIX Shrinkage cracks Figure 1 Shrinkage Cracks 4. Identification of lead-free solder on PCBs For PCBs that use lead-free solder, "LF" is indicated by silk-screen printing or attaching a label. "LF" stands for lead free and indicates that the PCBs bearing such an indication have been soldered with lead-free solder.
  • Page 298 APPENDIX PR2002179 Lead-free solder does not contain the toxic substance lead, however, inhalation of the fumes may adversely affect the health of workers. The silver contained in lead-free solder is also a toxic substance, though it is not as toxic as lead, and, therefore, a localized ventilation system and gloves are required for lead-free solder soldering operations, as required for those with conventional solder.
  • Page 299: How To Rewrite Hl-1850/1870N Flash Rom

    APPENDIX APPENDIX 22. HOW TO REWRITE HL-1850/1870N FLASH ROM The ROM composition of each PCB is as follows. Main PCB ROM 0 (64 Mbit x 2) ROM 1 (8 Mbit x 2) Production MASK FLASH Spares FLASH FLASH Working contents 1) Rewrite a Main firmware / Network firmware 2) Set up by country.
  • Page 300 APPENDIX Controller Firmware (ROM 0) Rewriting procedure (For AVA file) (1) Choose Start…>Program…>MS-DOS Since the DOS window is opened, move the “ZLHE” folder. Type c:\ZLHE and then press “Enter” key. (2) Connect the parallel cable to the printer, then turn the printer power switch ON. Wait until the printer LCD display turn green and “READY”...
  • Page 301 APPENDIX Patch Area (ROM 1) (1) Install the printer driver to the PC. Make an short-cut icon for FILEDG32 on the Desktop. (2) Connect the parallel cable to the printer. (3) Double click the FILEDG32 icon, and drag and drop the ROM2 data to the printer icon in the FILEDG32.
  • Page 302 APPENDIX PR2002109 APPENDIX 23. TONER CARTRIDGE WEIGHT INFORMATION Toner Cartridge Weight (approx weight) Before M4JN000001B, M4JN000001C (Serial No.) TN7600/TN560 Brand new Toner Cartridge Weight 827.5g Toner Weight at Brand New Toner Cartridge 197.5±2.5g Toner Cartridge Weight at Toner Near Empty 720-725g Remain Toner Weight at Toner Near Empty 90-95g...

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Hl-1870n