Digital Equipment LN15 Troubleshooting guide

SERVICE MANUAL
&
PARTS CATALOG
DIGITAL Laser Printer LN15
EK-LN15X-SV.A01

i
CONTENTS
CHAPTER 1 GENERAL DESCRIPTION.................................................................................................. 1-1
1.1 INTRODUCTION ...................................................................................................................................... 1-1
1.2 EQUIPMENT CONSTRUCTION ............................................................................................................. 1-2
1.2.1 General................................................................................................................................................. 1-2
1.2.2 Model Configuration ........................................................................................................................... 1-2
1.2.3 Structure............................................................................................................................................... 1-4
(1) Covers ........................................................................................................................................ 1-6
(2) Laser unit.................................................................................................................................... 1-7
(3) Printer mechanism...................................................................................................................... 1-8
(4) Print unit (user replaceable) ....................................................................................................... 1-9
(5) Cleaner assembly ....................................................................................................................... 1-9
(6) Power supply unit..................................................................................................................... 1-10
(7) Shield plate............................................................................................................................... 1-11
(8) Control board ........................................................................................................................... 1-11
(9) Sensor board assembly ............................................................................................................. 1-12
(10) Paper tray ................................................................................................................................. 1-12
(11) Multi-function feeder ............................................................................................................... 1-12
CHAPTER 2 INSTALLATION.................................................................................................................... 2-1
2.1 GENERAL DESCRIPTION ....................................................................................................................... 2-1
2.2 INSTALLATION PRECAUTIONS ........................................................................................................... 2-1
2.3 UNPACKING ............................................................................................................................................. 2-2
2.4 INSPECTION AFTER UNPACKING ....................................................................................................... 2-3
CHAPTER 3 TROUBLESHOOTING ......................................................................................................... 3-1
3.1 WHEN THE POWER INDICATOR DOES NOT LIGHT ........................................................................ 3-3
3.2 WHEN PRINTING QUALITY IS ABNORMAL......................................................................................3-4
(1) When faint .................................................................................................................................. 3-5
(2) When deep.................................................................................................................................. 3-6
(3) Black vertical line ...................................................................................................................... 3-7
(4) White vertical line ...................................................................................................................... 3-8
(5) Lacking space at the top and bottom..........................................................................................3-9
(6) Black point, white point ........................................................................................................... 3-10
(7) Second printing (ghost printing) .............................................................................................. 3-11
(8) Dirty back/edge ........................................................................................................................ 3-12

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(9) Black ........................................................................................................................................ 3-13
(10) White ........................................................................................................................................ 3-14
(11) Blur........................................................................................................................................... 3-15
(12) Smudge..................................................................................................................................... 3-16
3.3 ERROR AND STATUS MESSAGES .....................................................................................................3-17
3.3.1 Error Messages .................................................................................................................................. 3-17
3.3.2 Status Messages ................................................................................................................................. 3-18
3.4 RESETTING THE PRINT UNIT (FUSER UNIT) COUNTER .............................................................. 3-20
3.5 OTHERS ................................................................................................................................................... 3-22
CHAPTER 4 MAINTENANCE.................................................................................................................... 4-1
4.1 GENERAL .................................................................................................................................................. 4-1
4.2 GENERAL PRECAUTIONS ..................................................................................................................... 4-1
4.3 MAINTENANCE TOOLS ......................................................................................................................... 4-2
4.4 MAINTENANCE LEVELS ....................................................................................................................... 4-3
4.5 PREVENTIVE MAINTENANCE ............................................................................................................. 4-3
4.6 PARTS DRAWINGS ................................................................................................................................. 4-4
4.7 PARTS THAT MUST NOT BE DISASSEMBLED..................................................................................4-6
4.8 LEVEL 1 MAINTENANCE ......................................................................................................................4-7
4.8.1 Cleaning ............................................................................................................................................... 4-7
4.8.2 Consumables Replacement .................................................................................................................. 4-9
4.9 LEVEL 2 MAINTENANCE ....................................................................................................................4-11
4.9.1 Replacement ...................................................................................................................................... 4-11
(1) Upper cover replacement ......................................................................................................... 4-12
(2) Control panel replacement ....................................................................................................... 4-15
(3) Laser unit replacement ............................................................................................................. 4-18
(4) Fuser unit replacement ............................................................................................................. 4-19
(5) Power supply board replacement ............................................................................................. 4-21
(6) FAN 1 replacement .................................................................................................................. 4-22
(7) FAN 2 replacement .................................................................................................................. 4-23
(8) Control board replacement ....................................................................................................... 4-24
(9) High-voltage power supply board and sensor board replacement ........................................... 4-25
(10) Main motor replacement .......................................................................................................... 4-27
(11) Pick-up motor replacement ...................................................................................................... 4-28
(12) Pick-up roller replacement ....................................................................................................... 4-29
(13) Resist motor replacement .........................................................................................................4-31
(14) Paper feed roller replacement .................................................................................................. 4-32
(15) Transfer charger unit replacement ........................................................................................... 4-35

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(16) Cover-open switch replacement ............................................................................................... 4-36
(17) Volume board replacement ...................................................................................................... 4-37
(18) Stacker-full sensor board (SFS board) replacement ................................................................ 4-38
(19) Frame-2 assembly replacement................................................................................................ 4-39
(20) Multi-function feeder board (MFF board) replacement........................................................... 4-40
(21) Separator assembly (friction pad holder) replacement............................................................. 4-41
(22) Print unit disassembly .............................................................................................................. 4-42
4.9.2 Lubrication and Precautions .............................................................................................................. 4-43
(1) Base frame assembly................................................................................................................4-44
(2) Frame L assembly .................................................................................................................... 4-45
(3) Fuser unit.................................................................................................................................. 4-46
(4) Main motor unit .......................................................................................................................4-47
(5) Frame-2 assembly .................................................................................................................... 4-48
(6) Guide assembly ........................................................................................................................ 4-49
(7) Feed-2 assembly....................................................................................................................... 4-50
(8) Gear box assembly ................................................................................................................... 4-51
(9) Gear box lever assembly .......................................................................................................... 4-52
(10) Developing unit ........................................................................................................................ 4-53
(11) Magnet roller bracket assembly ............................................................................................... 4-55
(12) Heat roller subunit....................................................................................................................4-56
(13) Heat roller base unit ................................................................................................................. 4-57
4.10 DIAGNOSTICS ........................................................................................................................................ 4-58
4.10.1 Printing the Status Report .................................................................................................................. 4-58
4.10.2 MarkVision, Printer Management Utility Program by Lexmark....................................................... 4-61
(1) Installing MarkVision .............................................................................................................. 4-61
(2) Menu bar functions .................................................................................................................. 4-62
4.10.3 PPMENU Program ............................................................................................................................ 4-63
(1) Installing PPMENU ................................................................................................................. 4-63
(2) Menu functions and items ........................................................................................................ 4-64
4.10.4 Special Functions for Maintenance ...................................................................................................4-67
(1) Maintenance modes.................................................................................................................. 4-67
(2) How to execute a maintenance mode.......................................................................................4-68
(3) Information printed in test print mode ..................................................................................... 4-69
(4) EEPROM CLEAR and EEPROM CLEAR Extension ............................................................ 4-70
(5) Re-entry of the serial number of printer...................................................................................4-70

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CHAPTER 5 DESCRIPTION OF OPERATION....................................................................................... 5-1
5.1 GENERAL .................................................................................................................................................. 5-1
5.2 MECHANICAL OPERATION .................................................................................................................. 5-2
5.3 ELECTRICAL OPERATION .................................................................................................................... 5-6
5.3.1 System Diagram................................................................................................................................... 5-6
5.3.2 Main Controller ................................................................................................................................... 5-8
(1) CPU .......................................................................................................................................... 5-10
(2) RAM......................................................................................................................................... 5-10
(3) ROM......................................................................................................................................... 5-10
(4) Expansion interface .................................................................................................................. 5-11
(5) LSI-1 ........................................................................................................................................ 5-11
(6) Print density converter LSI ...................................................................................................... 5-13
(7) Reset circuit.............................................................................................................................. 5-13
5.3.3 Engine Controller Block Diagram ..................................................................................................... 5-15
(1) CPU .......................................................................................................................................... 5-17
(2) ROM......................................................................................................................................... 5-18
(3) LSI............................................................................................................................................ 5-18
5.3.4 Interface Communication Method ..................................................................................................... 5-19
(1) Centronics parallel interface .................................................................................................... 5-19
(2) RS-232C interface (option) ...................................................................................................... 5-20
(3) FEIT (Fujitsu Enhanced Imaging Technology) ....................................................................... 5-21
5.3.5 Printing Method ................................................................................................................................. 5-22
(1) Print control process................................................................................................................. 5-22
(2) Bit-map data generate .............................................................................................................. 5-22
(3) Video data transfer ................................................................................................................... 5-23
(4) LD unit ..................................................................................................................................... 5-23
(5) Heat roller temperature control ................................................................................................ 5-23
(6) Power saving control................................................................................................................5-24
(7) Alarm detect ............................................................................................................................. 5-24
5.3.6 Control Panel Control ........................................................................................................................ 5-25
5.3.7 Power Supply..................................................................................................................................... 5-26
(1) Overcurrent protection ............................................................................................................. 5-26
(2) Overvoltage protection............................................................................................................. 5-26
(3) PW STOP signal ...................................................................................................................... 5-26
CHAPTER 6 REPLACEMENT PARTS ..................................................................................................... 6-1

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ILLUSTRATIONS AND TABLES
Figure 1-1 Digital Laser Printer LN15 ............................................................................................................... 1-3
Figure 1-2 Structure ............................................................................................................................................ 1-5
Figure 1-3 Laser Unit .......................................................................................................................................... 1-7
Figure 1-4 Printer Mechanism ............................................................................................................................ 1-8
Figure 1-5 Power Supply Unit .......................................................................................................................... 1-10
Figure 1-6 Control Board .................................................................................................................................. 1-11
Figure 2-1 Shipping Carton and Printer and its Accessories ............................................................................. 2-2
Figure 2-2 Status Report (FPS Emulation)......................................................................................................... 2-6
Figure 3-1 Printer Elements and Connections.................................................................................................... 3-2
Figure 3-2 Abnormal Print Quality .................................................................................................................... 3-4
Figure 4-1 Basic Components............................................................................................................................. 4-4
Figure 4-1 Basic Components - Continued ........................................................................................................ 4-5
Figure 4-2 Cleaning the Paper Path .................................................................................................................... 4-8
Figure 4-3 Cleaning the Corona Wire ................................................................................................................ 4-8
Figure 4-4 Cleaning the Precharger Wire........................................................................................................... 4-9
Figure 4-5 Status Report (FPS Emulation)....................................................................................................... 4-59
Figure 4-6 Front Report (FPS Emulation) ........................................................................................................ 4-60
Figure 4-7 MarkVision Main Screen (Initial Status) ....................................................................................... 4-62
Figure 4-8 MarkVision Status Screen (Cover Open) ....................................................................................... 4-63
Figure 4-9 PPMENU Main Menu (Concept) .................................................................................................... 4-64
Figure 4-10 Maintenance Mode Operation Flowchart ..................................................................................... 4-71
Figure 5-1 Printer Block Diagram ...................................................................................................................... 5-1
Figure 5-2 Picking, Printing, Fusing, and Ejecting Paper .................................................................................. 5-2
Figure 5-3 Structure of the Paper Feed Drive Unit ............................................................................................ 5-3
Figure 5-4 Process Drive Unit ............................................................................................................................ 5-4
Figure 5-5 Print Unit ........................................................................................................................................... 5-5
Figure 5-6 System Diagram ................................................................................................................................ 5-6
Figure 5-7 Connection Diagram ......................................................................................................................... 5-7
Figure 5-8 Main Controller Block Diagram ....................................................................................................... 5-9
Figure 5-9 Control Board Block Diagram ........................................................................................................ 5-14
Figure 5-10 Engine Controller Block Diagram ................................................................................................ 5-16
Figure 5-11 Centronics Parallel Interface Signal Timing Chart ...................................................................... 5-19
Figure 5-12 RS-232C Serial Interface Signal Timing Chart............................................................................ 5-20
Figure 5-13 Block Diagram (Internal Configuration) ...................................................................................... 5-21
Figure 5-14 Print Process Block Diagram ........................................................................................................ 5-22
Figure 5-15 Video Data Transfer Block Diagram ............................................................................................ 5-23
Figure 5-16 Control Panel Block Diagram ....................................................................................................... 5-25
Figure 5-17 Power Supply Block Diagram ....................................................................................................... 5-27

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Table 3-1 Error Messages.................................................................................................................................. 3-17
Table 3-2 Action-required Status Messages...................................................................................................... 3-18
Table 3-3 Printer Status Messages .................................................................................................................... 3-19
Table 4-1 Maintenance Tools .............................................................................................................................. 4-2
Table 4-2 Parts That Must Not be Disassembled ................................................................................................ 4-6
Table 4-3 Cleaning .............................................................................................................................................. 4-7
Table 4-4 PPMENU Factory Defaults When Emulation is PCL ...................................................................... 4-66
Table 4-5 Special Maintenance Modes ............................................................................................................. 4-67

PREFACE
This manual is for maintenance engineers and discusses the operation, installation, and maintenance of the
DIGITAL Laser Printer LN15. The topics covered are:
Chapter 1: Printer specifications, performance, and configuration
Chapter 2: Installation precautions and unpacking
Chapter 3: Diagnosing mechanical and electronic problems
Chapter 4: Maintenance procedures (cleaning, lubrication, inspection, adjustment), procedures for replacing
parts, and list of tools
Chapter 5: Principles of operation (mechanical and electrical operations)
Chapter 6: Replacement parts

1-1
CHAPTER 1 GENERALDESCRIPTION
1.1 INTRODUCTION
This manual is for maintenance service engineers. The DIGITAL Laser printer LN15 is based on the QMS
Desklaser 1400P printer that is manufactured by Fujitsu using the PrintPartner 14ADV printer engine. This
manual is customized for the DIGITAL Laser Printer LN15 from the PrintPartner 14ADV Service Manual &
Part Catalog. It covers maintenance and detailed information such as trouble-shooting and component replace-
ment. Information unique to the DIGITAL Laser printer LN15 are documented.
DIGITAL Laser Printer LN15 Service Manual and Parts Catalog (EK-LN15X-SV)
There are two companion manuals for PrintPartner 14ADV maintenance service engineers:
PrintPartner 14ADV Page Printer Parts Catalogue (Order No. C145-G019)
PrintPartner 14ADV Page Printer Schematic Diagrams (Order No. C145-F038)
For the optional duplex unit, the following manual is available.
Duplex Unit Parts Catalogue (Order No. C145-G020)
Most information is covered in this manual. The other two manuals are mostly for reference. These three
manuals contain all the information necessary for LN15 laser printer maintenance.
The LN15 laser printer is a reliable machine with a simple mechanism that requires little maintenance.

1-2
1.2 EQUIPMENT CONSTRUCTION
1.2.1 General
This section outlines the construction and features of the LN15 laser printer .
1.2.2 Model Configuration
Printer
Model and input voltage
LN15P-AC : 220–240 VAC (for Europe), 11MB, No Network card +
central Europe power cord
LN15N-AC : 220–240 VAC (for Europe), 19MB, Ethernet Card
10-BASE-2 (BNC) + Central Europe power cord
LN15N-AB : 220–240 VAC (for Europe), 19MB, Ethernet Card
10-BASE-T (Twisted pair) + Central Europe power cord
LN15X-TA Paper trays (tray 1; 550 sheets): A4, Letter, and Legal sizes
LN15X-TB Paper trays (tray 2; 500 sheets): A4, A5, Letter, Legal, and
Executive sizes
LN15X-TC Paper feeder (feeder unit + paper tray 2): A4 or Letter size
LN15X-DA Duplex unit (two-sided printing mechanism)
LN15X-SI Serial interface board RS-232C/422A (For LN15P)
LN15X-AT LocalTalk board: AppleTalk compatible (For LN15P)
LN15X-NA Ethernet board 10-BASE-2 (for LN15P)
LN15X-NB Ethernet board 10-BASE-T (for LN15P)
LNXXM-AE 8MB Memory expansion
LNXXM-AF 16MB Memory expansion
LNXXM-AG 32MB Memory expansion
LN15X-MF Multifunction Feeder paper tray
The entry model LN15P printer has 11 MegaBytes of RAM, HP LaserJet 4 (PCL5e) and PostScript level 2
emulations, and a Centronics parallel interface (bi-directional). Its paper tray size is A4 for Europe, Asia, and
Australia. The network printer models LN15N-AC and LN15N-BC have 19 MegaBytes HP LaserJet 4 (PCL5e)
and PostScript level 2 emulations, and a Ethernet card.
Options

1-3
[ Rear and left side view ]
Figure 1-1 LN15 Laser Page Printer
Control panel
Slide cover
(Font/emulation card slot
and RAM card slots inside)
Multi-function feeder
cable
Paper tray
Front cover
(opened)
Upper door
Top cover
(Paper stacker)
Stacker-full sensor
Multi-function feeder
(MFF)
Paper guides
for manual feeding
Paper guides
for stack feeding
Shade cover
(cleaner assembly inside)
[ Front and right side view]
Rear stacker
Power switch
Power cord
connector
Centronics parallel
interface connector
Interface board
slot cover

1-4
1.2.3 Structure
The standard printer without options has the following structure.
LN15 Laser printer Upper cover assembly
Ozone filter
Control panel
Shade cover
Side cover L
Side cover R
Front frame
Toner empty sensor
Front cover
Back cover
Rear stacker
Metal frame
Fan 1
Process drive mechanism
Main motor
Gears
Paper pick-up mechanism
Pick-up motor
Base frame
Paper sensor
Paper feed mechanism
Resist motor
Resist roller
Paper feed roller
Pick-up roller
Transfer charger unit
Paper guide assembly 2
Paper eject roller
Stack full sensor
Print unit guide
Cover open switch
Volume board
Print density dial
MFF board
Covers
Laser unit
Printer mechanism
Print unit OPC drum unit
Developing unit
Toner bottle
Cleaner assembly Cleaner
Cleaner holder
Power supply unit
Main power supply
Power switch
AC inlet
Fuser unit
Cover
Paper guide
assembly 1
Paper eject sensor
Paper guide
Guide open switch
Fan 2
Shield plate
Control board
Sensor board assembly
Sensor boards
High-voltage power supply board
Paper empty sensor
Paper tray
Friction pad holder
Multi-function feeder (MFF)

1-5
Printer + optional duplex unit + optional paper feeder
Eject roller
Upper cover
assembly
Paper feed roller
Resist roller
Toner bottle
Laser unitPrint unit
OPC drum
Paper feeder
(feeder unit +
paper tray)
(option)
Heat roller
(fuser unit)
Transfer charger unit
Pick-up roller
Figure 1-2 Structure
Paper tray 1
Paper tray 2
(option)
Multi-Function
feeder (Option)
Cleaner assembly
Duplex unit
(option)
: Paper path

1-6
(1) Covers
The covers consist of the following:
• Upper cover assembly
• Side cover L
• Side cover R
• Front frame
• Front cover
• Back cover
• Stacker
a. Upper cover assembly
The upper cover assembly covers the top of the printer mechanism and stacks printed paper.
The upper cover assembly has a hinge to enable the front (upper door) to open. The print unit and toner
bottle can be replaced when the upper door is open.
The upper cover has a hinge to enable the shade cover to open. The cleaner can be replaced when the shade
cover is open.
The control panel is located at the top right and the ozone filter is inserted at the right rear. It consists of
four LED indicators, an LCD, and eight push-button switches, enabling communication between the user
and printer.
b. Side cover L
This cover covers the left side of the printer mechanism.
c. Side cover R
This cover covers the right side of the printer mechanism.
This cover is opened to add or replace optional cards (RAM card or emulation card).
d. Front frame
This frame is secured to the front of the printer mechanism.
e. Front cover
This cover is opened when paper is fed manually or the multi-function feeder is used.
f. Back cover
This cover covers the rear of the printer mechanism.
g. Rear stacker
The rear stacker can be opened or closed to select the output destination of printed paper. The rear stacker is
usually closed to eject paper to the upper cover side.
When envelopes, labels, or transparencies are used, the rear stacker must be opened to eject paper to the rear
and stack it.
Also when a paper jam occurs, the rear stacker is opened to remove the jammed paper.

1-7
Caution label
▲ CAUTIO
N
!
(2) Laser unit
The laser unit is provided in the upper cover.
Images are written on the photoconductive drum of the print unit by laser beams emitted from the laser unit.
Figure 1-3 Laser Unit
: Do not look at a laser beam directly.
This label is put on the laser unit. “

1-8
(3) Printer mechanism
Figure 1-4 Printer Mechanism
a. Metal frame
This frame is the basic frame of the printer mechanism and made of sheet metals.
All parts are tightened with screws or snap-fitted to this frame.
The fan (FAN1) is installed on this frame.
b. Process drive mechanism
This mechanism consists of the mechanism that drives the print unit and fuser unit, a DC motor, and drive
system (gears, etc.).
c. Paper pick-up mechanism
This mechanism feeds paper loaded in the paper tray to the base frame of the printer mechanism sheet by
sheet.
This mechanism consists of a stepping motor and drive system (gears, etc.).
d. Base frame
This frame is main part of the mechanism that transports paper and transfers toner to the paper.
• Sensor that detects the picked paper
• Transfer charger unit (service technicians replaceable)
• Paper feed mechanism
(A stepping motor, resist roller, paper feed roller, and pick-up roller are tightened with screws or snap-
fitted to this frame.)

1-9
e. Paper guide assembly 2
This guide transports printed paper to the output stacker. This guide is snap-fitted to the frame on which the
paper eject roller is installed.
The stacker-full sensor is installed on this assembly.
f. Print unit guide
This guide is used to install the print unit in the printer.
The cover open switch that detects opening and closing of the upper door is installed on the left guide.
This guide is snap-fitted to the frame.
g. Volume board
The volume board has a variable resistor to control the print density. The control dial is accessible when the
upper door is open.
h. Multi-function feeder board (MFF board)
This board has a connector for the multi-function feeder (MFF).
(4) Print unit (user replaceable)
The print unit consists of a photoconductive (OPC) drum unit and a developing unit. It lasts about 30,000
pages printed at 5% coverage in continuous print mode at 25°C (77°F) and 50% RH.
It can be changed easily by the user.
a. Toner bottle (user replaceable)
The toner bottle contains new toner. It lasts for about 5,000 pages printed at 5% coverage in continuous
print mode. However, the toner bottle installed on the new print unit has a shorter life. It can be changed
easily by the user.
(5) Cleaner assembly
The cleaner assembly consists of a cleaner and a cleaner holder..
a. Cleaner (user replaceable)
The cleaner wipes the heat roller. It lasts for about 5,000 pages printed at 5% coverage in continuous print
mode. It must be replaced by the user when the toner bottle is empty and replaced.
b. Cleaner holder (reusable)
The cleaner holder holds the cleaner. It locks the cleaner by a simple mechanism which can be easily
operated by the user.

1-10
(6) Power supply unit
This unit consists of the following parts:
• Main power supply
- Power switch
- AC inlet
• Fuser unit
- Cover
- Paper guide assembly 1
- Paper eject sensor
- Paper guide
- Guide open switch
• Fan (FAN 2)
a. Main power supply
The main power supply supplies +5 VDC and +24 VDC for the logic devices and printer mechanism.
There are two types of power supplies: one for input voltage of 120 VAC (not used on LN15) and the
other for 220 to 240 VAC.
The main power supply is equipped with a power switch and an AC inlet.
The main power supply is attached with screws to the cover of the fuser unit.
Figure 1-5 Power Supply Unit
b. Fuser unit (service technicians replaceable)
The fuser unit has an aluminium heat roller and a pressure roller. It fixes the image of toner particles on the
paper using heat and pressure.
It has a temperature sensor and a thermal fuse for safety.
It lasts about for 100,000 pages printed at 5% coverage on A4 paper in continuous print mode. There are
two types: one for input voltage of 120 VAC (Not used on LN15) and the other for 220 to 240 VAC.

1-11
c. Cover
This cover, classified as a component belonging under the fuser unit category, covers the main power
supply. It is attached on the bottom of the fuser unit and the power supply is installed under (inside) the
cover. The paper guide assembly 1 is also installed at the edge of the cover.
d. Paper guide assembly 1
This assembly transports paper from the fuser unit to the eject roller.
When a paper jam occurs, the paper guide assembly can be drawn out to remove the jammed paper.
A guide open switch detects normal installation of the paper guide assembly.
e. Fan (FAN 2)
This fan ventilates the power supply unit.
This fan is tightened with screws to the right side of the power supply unit.
(7) Shield plate
This plate covers the control board.
This plate is tightened with screws to the right side of the printer mechanism frame.
(8) Control board
The control board is the main controller of this printer. It has four ROMs for firmware, mechanism control,
and interface control. It has connectors for the Centronics interface cable and an optional interface board, an
optional memory expansion cards, and an emulation card of the future. The resident RAM is 3 MBytes.
There is 1 x 8 MB SIMMS board on the LN15P and 2 x 8 MB SIMMS board on LN15N as standard
configuration.
Figure 1-6 Control Board

1-12
(9) Sensor board assembly
a. Sensor boards
There are two sensor boards.
They detect the presence of paper, the size of paper, paper empty, and paper ejection.
b. High-voltage power supply board (HV board)
The high-voltage power supply, which supplies high voltage to the pre-charger and the transfer charger unit,
is tightened with screws to the left side of the sensor board assembly.
(10)Paper tray
The paper size is universal among A4, Letter, and Legal. The capacity of the paper tray (tray 1) is 550
sheets for 0.09 mm thick paper. An optional 500-sheet paper feeder (tray 2) is provided. Its paper size is
universal among A4, A5, Letter, Legal, and Executive.
(11)Multi-function feeder (Optional)
The multi-function feeder feeds envelopes, labels, transparencies, heavy paper, and nonstandard size paper.
The capacity is 100 sheets for 0.09 mm thick paper or 30 envelopes.