Brother HL-2400C Series User manual

Brother Color Laser Printer
SERVICE MANUAL
MODEL: HL-2400C / 2400Ce
Read this manual thoroughly before maintenance work.
Keep this manual in a convenient place for quick and easy reference at all times.
February 2000
54S002BE0
PR2000036

© Copyright Brother 2000
All rights reserved.
No part of this publication may be reproduced in any form or by any means without permission in
writing from the publisher.
Specifications are subject to change without notice.
Trademarks:
The brother logo is a registered trademark of Brother Industries, Ltd.
Apple, the Apple Logo, and Macintosh are trademarks, registered in the United States and other
countries, and True Type is a trademark of Apple computer, Inc.
Epson is a registered trademark and FX-80 and FX-850 are trademarks of Seiko Epson
Corporation.
Hewlett Packard is a registered trademark and HP Laser Jet is a trademark of Hewlett Packard
Company.
IBM, IBM PC and Proprinter are registered trademarks of International Business Machines
Corporation.
Microsoft and MS-DOS are registered trademarks of Microsoft Corporation.
Windows is a registered trademark of Microsoft Corporation in the U.S. and other countries.
PR2000036

PREFACE
This service manual contains basic information required for after-sales service of the color laser
printer (here-in-after referred to as "this machine" or "the printer"). This information is vital to the
service technician to maintain the high printing quality and performance of the printer.
This service manual covers the HL-2400C / 2400Ce color laser printer.
This manual consists of the following chapters:
CHAPTER I : OUTLINE OF PRODUCT
Features, parts names, internal structure, and description of the control panel.
CHAPTER II : SPECIFICATIONS
Specifications, etc.
CHAPTER III : INSTALLATION
Installation conditions and installation procedures.
CHAPTER IV : STRUCTURE OF SYSTEM COMPONENTS
Basic operation of the mechanical system, the electrical system and the electrical
circuits and their timing information.
CHAPTER V : CONTROL PANEL OPERATION
Operation and setting procedures on the control panel.
CHAPTER VI : PERIODIC MAINTENANCE
Description of periodic maintenance parts, and procedures for periodic
replacement and cleaning.
CHAPTER VII : DISASSEMBLY
Procedures for replacement of the mechanical system parts.
CHAPTER VIII : TROUBLESHOOTING
Description of error messages on the control panel, troubleshooting image
failure, etc.
APPENDICES :SERIAL NO. DESCRIPTIONS, ETC.
Information in this manual is subject to change due to improvement or re-design of the product. All
relevant information in such cases will be supplied in service information bulletins (Technical
Information).
A thorough understanding of this printer, based on information in this service manual and service
information bulletins, is required for maintaining its print quality performance and for improving the
practical ability to find the cause of problems.
PR2000036

CONTENTS
CHAPTER I PRODUCT OUTLINE....................................................I-1
1. FEATURES......................................................................................................I-1
2. PARTS NAMES & FUNCTIONS......................................................................I-4
3. INTERNAL STRUCTURE................................................................................I-6
4. DESCRIPTION OF CONTROL PANEL...........................................................I-7
4.1 Video Controller Mode...........................................................................................................I-7
4.2 Engine Controller Mode.........................................................................................................I-7
CHAPTER II SPECIFICATIONS......................................................II-1
1. RATING..........................................................................................................II-1
2. GENERAL SPECIFICATIONS........................................................................II-2
2.1. Printing................................................................................................................................II-2
2.2. Functions.............................................................................................................................II-3
2.3. Electrical and Mechanical...................................................................................................II-3
2.4. Paper Specification.............................................................................................................II-4
3. ENVIRONMENTAL CONDITION.....................................................................II-8
3.1 Ambient Temperature / Humidity / Altitude...........................................................................II-8
CHAPTER III INSTALLATION........................................................III-1
1. CONDITIONS REQUIRED FOR INSTALLATION.........................................III-1
1.1. Environmental Conditions..................................................................................................III-1
1.2. Basic Layout of Printer Set-up Location.............................................................................III-1
2. UNPACKING.................................................................................................III-2
2.1 Unpacking of Printer............................................................................................................III-2
2.2 Unpack the Starter Kit.........................................................................................................III-4
3. INSTALLATION WORK.................................................................................III-5
3.1 Install the OPC Belt Cartridge.............................................................................................III-5
3.2 Install the Toner Cartridge to the Printer.............................................................................III-6
3.3 Install the Oil Bottle and Fuser Cleaner..............................................................................III-7
3.4 Test Print.............................................................................................................................III-8
CHAPTER IV STRUCTURE OF SYSTEM COMPONENTS............IV-1
1. BASIC STRUCTURE.....................................................................................IV-1
1.1 Print System and Transfer System....................................................................................IV-6
1.2 Scanning System.............................................................................................................IV-21
1.3 Paper Transportation System..........................................................................................IV-23
1.4 Fusing Unit.......................................................................................................................IV-25

2. STRUCTURE OF THE CONTROL SYSTEM..............................................IV-27
2.1 Basic Structure............................................................................................................IV-27
2.2 Control System............................................................................................................ IV-36
2.3 Main PCB(Video Controller PCB) ............................................................................... IV-46
2.4 Power Supply Unit....................................................................................................... IV-70
2.5 High Voltage Power Supply Unit.................................................................................. IV-73
2.6 Wiring Diagram............................................................................................................ IV-76
CHAPTER V CONTROL PANEL OPERATION................................V-1
1. PANEL LAYOUT ............................................................................................V-1
2. VIDEO CONTROLLER MODE.......................................................................V-2
2.1 Configuration of Operational Mode .................................................................................V-2
2.2 Toner Save Mode / Power Save Mode ...........................................................................V-3
2.3 Line Test Mode ..............................................................................................................V-4
2.4 DRAM Test Mode...........................................................................................................V-8
2.5 Program Version Display Mode ......................................................................................V-9
2.6 Test Print Mode............................................................................................................V-10
2.7 NVRAM Reset Mode.................................................................................................... V-10
3. ENGINE CONTROLLER MODE ..................................................................V-11
3.1 Configuration of Operational Mode ............................................................................... V-11
3.2 Operation of Normal Mode ........................................................................................... V-13
3.3 Service Mode ...............................................................................................................V-19
3.4 Adjustment Work Procedures....................................................................................... V-39
CHAPTER VI PERIODIC MAINTENANCE ...................................... VI-1
1. GENERAL .....................................................................................................VI-1
1.1 Handling Precautions.....................................................................................................VI-1
1.2 Periodic Maintenance Cleaning......................................................................................VI-4
1.3 Periodic Maintenance Parts and Maintenance Cycle.................................................... VI-15
2. PERIODIC MAINTENANCE PROCEDURES..............................................VI-18
2.1 OPC Belt Cartridge Replacement ................................................................................ VI-18
2.2 Fusing Unit Replacement ............................................................................................ VI-20
2.3 Transfer Roller Replacement....................................................................................... VI-22
2.4 Paper Discharger Unit Replacement............................................................................ VI-24
2.5 Drum Cleaner Replacement ........................................................................................VI-26
2.6 Ozone Filter Replacement........................................................................................... VI-28
2.7 Paper Feed Roller and Separator Pad Replacement.................................................... VI-29
2.8 Transfer Drum Replacement........................................................................................ VI-30
PR2000036

CHAPTER VII DISASSEMBLY.....................................................VII-1
1. BEFORE STARTING DISASSEMBLY..........................................................VII-1
1.1 Precautions.......................................................................................................................VII-1
1.2 Preparation of Disassembly..............................................................................................VII-1
2. PARTS NAME..............................................................................................VII-3
2.1 Cover.................................................................................................................................VII-3
2.2 Circuit Boards (PCBs).......................................................................................................VII-4
2.3 Motor Units........................................................................................................................VII-4
2.4 Clutches and Solenoids....................................................................................................VII-5
2.5 Sensors.............................................................................................................................VII-6
3. DISASSEMBLY FLOW.................................................................................VII-7
4. DISASSEMBLY PROCEDURE.....................................................................VII-8
4.1 Right Side of the Printer....................................................................................................VII-8
4.2 Top of the Printer............................................................................................................VII-17
4.3 Left Side of the Printer.....................................................................................................VII-26
4.4 Paper Exit Unit................................................................................................................VII-33
4.5 Front of the Printer..........................................................................................................VII-38
4.6 Rear of the Printer...........................................................................................................VII-40
4.7 Fusing Unit......................................................................................................................VII-44
CHAPTER VIII TROUBLESHOOTING.........................................VIII-1
1. OUTLINE OF TROUBLESHOOTING..........................................................VIII-2
2. OPERATOR CALL.......................................................................................VIII-3
2.1 Video Controller Mode......................................................................................................VIII-3
2.2 Engine Controller Mode....................................................................................................VIII-6
3. PAPER TRANSPORT ERROR....................................................................VIII-8
3.1 Feed Jam.........................................................................................................................VIII-8
3.2 Inner Jam.........................................................................................................................VIII-9
3.3 Outer Jam........................................................................................................................VIII-9
3.4 Others..............................................................................................................................VIII-9
4. SERVICE CALL.........................................................................................VIII-10
4.1 Video Controller Mode....................................................................................................VIII-11
4.2 Engine Controller Mode..................................................................................................VIII-13
5. IMAGE FAILURE.......................................................................................VIII-41
APPENDIX A....................................................................................A-1

i
REGULATIONS
LASER SAFETY (FOR 110-120 V MODEL ONLY)
This printer is certified as a Class I laser product under the U.S. Department of Health and
Human Services (DHHS) Radiation Performance Standard according to the Radiation
Control for Health and Safety Act of 1968. This means that the printer does not produce
hazardous laser radiation.
Since radiation emitted inside the printer is completely confined within protective housings
and external covers, the laser beam cannot escape from the machine during any phase of
user operation.
FDA REGULATIONS (FOR 110-120 V MODEL ONLY)
U.S. Food and Drug Administration (FDA) has implemented regulations for laser products
manufactured on and after August 2, 1976. Compliance is mandatory for products
marketed in the United States. One of the following labels on the back of the printer
indicates compliance with the FDA regulations and must be attached to laser products
marketed in the United States.
Caution
Use of controls, adjustments or performance of procedures other than those specified in
this manual may result in hazardous radiation exposure.

ii
IEC 825 SPECIFICATION (FOR 220-240 V 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.
CLASS 1LASER PRODUCT
APPAREIL Å LASER DE CLASSE 1
LASER KLASSE 1 PRODUKT
This printer has a Class 3B Laser Diode which emits invisible laser radiation in the Scanner
Unit. The Scanner Unit should not be opened under any circumstances.
Caution
Use of controls, adjustments or performance of procedures other than those specified in
this manual may result in hazardous radiation exposure.
The following caution label is attached near the scanner unit.
5mW
780nm-800nm
DANGER-
INVISIBLE LASER RADIATION WHEN OPEN.
AVOID DIRECT EXPOSURE TO BEAM.
VORSICHT -
UNSICHTBARE LASERSTRAHLUNG, WENN ABDECKUNG
GEÖFFNET UND SICHERHEITSVERRIEGELUNG
ÜBERBRÜCKT. NICHT DEM STRAHL AUSSETZEN.
DANGER-
RAYON LASER INVISIBLE LORS DE L’OUVER TURE.
EVITER L’EXPOSITION DIRECTE.
PELIGRO-
RADIACION LASER INVISIBLE AL ABRIR. EVITAR
LA EXPOSICION DIRECTA AL HAZ.
MAS
For Finland and Sweden
LUOKAN 1 LASERLAITE
KLASS 1 LASER APPARAT
Varoitus! Laitteen käyttäminen muulla kuin tässä käyttöohjeessa mainitulla tavalla saattaa
altistaa käyttäjän turvallisuusluokan 1 ylittävälle näkymättömälle lasersäteilylle.
Varning – Om apparaten används på annat sätt än i denna Bruksanvisning specificerats,
kan användaren utsättas för osynlig laserstrålning, som överskrider gränsen för laserklass
1.

iii
SAFETY INSTRUCTIONS
SAFETY PRINCIPLE
1) Before starting any operations, read this manual thoroughly. Especially read the safety
instructions in this section carefully and ensure that you understand the contents.
2) Perform all the operations by following the procedures described in this manual. Follow
all the cautions and warnings set out in the procedures and on safety labels affixed to
the machine. Failure to do so may result in human injury or equipment damage.
3) Perform only the procedures explained in this manual. Refrain from opening or touching
any portions that are not related to your required operation(s).
4) Repair and replacement of parts should be performed by trained and qualified persons
only. Operators should not attempt to do such repair or replacement work.
5) It must be appreciated that the above-mentioned cautions and warnings do not cover
everything because it is impossible to evaluate all the circumstances of repair
situations.
SPECIAL SAFETY INFORMATION
Introductory Information
Cautions and warnings are made clear by following the ‘Safety Alert Symbols’ or ‘Signal
Words’ such as DANGER, WARNING and CAUTION.
<SAFETY ALERT SYMBOL>
This is the safety alert. When you find this symbol placed on the equipment or marked in
this manual, be aware of the potential of human injuries. Follow the recommended
precautions and safety operation practices.
<Understanding Signal Words>
DANGER is used to indicate the presence of a hazard which will cause severe human
injuries or a fatal accident if the warning is ignored.
WARNING is used to indicate the presence of a hazard or unsafe practices which may
cause severe human injuries or a fatal accident if the warning is ignored.
CAUTION is used to indicate the presence of a hazard or unsafe practices which may
cause minor human injuries if the warning is ignored. CAUTION also calls your attention to
safety messages in this manual.
<Follow Safely Instructions>
Carefully read all the safety messages set out in this manual and also in the safety warning
signs placed on the equipment. In this manual, the safety instructions (safety alert symbols
and signal words) are enclosed in a rectangular enclosure to bring them to your attention.
Keep the safety signs on the equipment in good condition and ensure none are missing or
damaged. Replace the safety signs if unreadable or damaged. Learn how to operate the
equipment and how to use the controls properly. Do not let anyone operate this equipment
without following the instructions. Keep the equipment in proper working condition.
Unauthorized modification to the equipment may impair the function & safety and affect the
life of the equipment.
Listed below are the various kinds of “WARNING” messages contained in this manual.

iv
WARNING
HAZARDOUS VOLTAGE
May cause serious injuries or fatal accidents. Voltage is now applied from
the power supply of printer. There is a danger of electrical shock if you
touch the active area inside the printer.
Be sure to turn the power supply switch OFF and pull the plug out from the
power outlet before starting maintenance work on the printer.
WARNING
HARMFUL OZONE GAS
Inhalation of an excessive amount of ozone gas may adversely affect the
respiratory organs.
An Ozone Filter is fitted to this printer to reduce the exhausted ozone. This
filter must be replaced with a new filter periodically in accordance with the
manual supplied with the printer.
WARNING
HOT SURFACE
The Fusing Unit reaches a temperature of approx.160°C and adjacent
parts are also very hot.
When you need to change the cleaning pad or remove jammed paper, wait
about 20 minutes after opening the paper exit unit to allow the unit to cool
down.
CAUTION
ROTATING PARTS
Be aware of the potential danger of various rollers and take care not to get
your fingers or hand caught into the machine, this can cause serious
injuries. Note that the exit roller that ejects the printed paper is rotating
while printing.
Be careful not to get your hair, fingers, hands, sleeve or necktie caught in
the machine while operating the machine.

v
CAUTION
HAZARDOUS POWDER
Toner is a fine powder which can cause a powder explosion if disposed of
into a fire. Under no circumstances dispose of toner into a fire.
CAUTION
HAZARDOUS POWDER
Toner is a fine powder which may cause irritation to the eyes and
respiratory organs if inhaled.
Handle the toner cartridge, waste toner pack and developing unit carefully
so as not to spill the toner.
CAUTION
POWER CORDS & PLUGS
This printer is equipped with a 3-wire power cord fitted with a 3-pronged
plug (bi-polar plug with grounding) for the user’s safety.
Use these power cords in conjunction with a properly grounded electrical
outlet to avoid an electrical shock.
CAUTION
SAFETY INTERLOCK
The front cover, paper exit unit and transfer unit of this printer have
electrical safety interlocks to turn the power off whenever they are opened.
Do not attempt to circumvent these safety interlocks.

vi
<Label Location>
1
2
3
1. Hot Caution Label
AVERTISSEMENT WARNING WARNUNG
Hot surface.
Avoid contact. Heiße oberfiäche. Bei beseitigung. Surface chaude. Eviter tout contact.
2. Laser Caution Label
5mW
780nm-800nm
DANGER-
INVISIBLE LASER RADIATION WHEN OPEN.
AVOID DIRECT EXPOSURE TO BEAM.
VORSICHT -
UNSICHTBARE LASERSTRAHLUNG, WENN ABDECKUNG
GEÖFFNET UND SICHERHEITSVERRIEGELUNG
ÜBERBRÜCKT. NICHT DEM STRAHL AUSSETZEN.
DANGER-
RAYON LASER INVISIBLE LORS DE L’OUVER TURE.
EVITER L’EXPOSITION DIRECTE.
PELIGRO-
RADIACION LASER INVISIBLE AL ABRIR. EVITAR
LA EXPOSICION DIRECTA AL HAZ.
MAS
3. Rating Label (For US)
NOVEMBER 1997
FCC ID : B3QHLC1
MODEL HL-C1
SER. NO.
120V ~ 50/60Hz 8.0A
BROTHER INDUSTRIES, LTD.
BROTHER PRINTER HL SERIES COVERED
BY ONE OR MORE FOLLOWING PATENTS:
U52492L7H111101
MADE IN JAPAN
CLASS 1 LASER PRODUCT
APPAREIL Å LASER DE CLASSE 1
LASER KLASSE 1 PRODUKT
MANUFACTURED;
BROTHER INDUSTRIES, LTD.
15-1, Naeshiro - cho, Mizuho -ku, Nagoya 467, Japan.
This product complies with FDA radiation
performance standards, 21 CFR Subchapter J.
This device complies with Part 15 of the FCC Rules. Operation is
subject to the following two conditions : (1) This device may
not cause harmful interference, and (2) this device must
accept any interference received, including interference that
may cause undesired operation.
HTJ
USP4, 968, 159 USP5, 050, 228 USP5, 068, 805
USP5, 086, 481 USP5, 093, 904 USP5, 126, 788
(For Europe)
MODEL HL-C1
SER. NO.
220V-240V~ 50/60Hz 4.0A
BROTHER INDUSTRIES, LTD.
E52619L7H111101
ACN 001 393 835
MADE IN JAPAN
TOV
ProductSafety CLASS 1 LASER PRODUCT
APPAREIL Å LASER DE CLASSE 1
LASER KLASSE 1 PRODUKT

vii
SHIPMENT OF THE PRINTER
If for any reason you must ship the printer, carefully package the printer to avoid any
damage during transit. It is recommended that you save and use the original packaging.
The printer should also be adequately insured with the carrier.
CAUTION
• When shipping the printer, remove the toner cartridges, the OPC belt
cartridge and the waste toner pack from the printer to prevent toner spill
in the printer or damage of the toner cartridge and the OPC belt
cartridge.
• When shipping the printer, remove the oil bottle and the fuser cleaner
from the fusing unit. After removing the oil bottle, be sure to remove the
oil remaining in the fusing unit with the supplied syringe. Failure to do so
will cause severe damage to the printer.

CHAPTER I
PRODUCT OUTLINE

CONTENTS
CHAPTER I PRODUCT OUTLINE...................................................I-1
1. FEATURES.....................................................................................................I-1
2. PARTS NAMES & FUNCTIONS.....................................................................I-4
3. INTERNAL STRUCTURE...............................................................................I-6
4. DESCRIPTION OF CONTROL PANEL..........................................................I-7
4.1 Video Controller Mode...........................................................................................................I-7
4.2 Engine Controller Mode.........................................................................................................I-7

I-1
CHAPTER I PRODUCT OUTLINE
1. FEATURES
This printer has the following features:
2400 x 600 dpi Class Resolution
The printer prints pages with a resolution of 600 dots per inch (dpi) as
default. It also provides higher quality printout which is the equivalent
of 2400 x 600 dpi resolution when using HRC or CAPT.
High Speed Color Laser Printing
The printer allows crisp printing in 24 bit brilliant color. The printer
prints at a speed of 16 pages per minute in monochrome mode and 4
pages per minute in full color mode. The controller utilizes a high
speed 32-bit RISC microprocessor and special hardware chips, which
provides a very fast processing speed.
High Resolution Control (HRC)
The high resolution control (HRC) technology provides clear and crisp
printouts and improves even the 600 dpi resolution. This mode is
effective when printing text data.
Color Advanced Photoscale Technology (CAPT)
The printer can print graphics in 256 shades for each color in HP®
color printer PCL5C™ and BR-Script level 2 emulations, producing
nearly photographic quality. This mode is effective when printing
photographic images.
Maintenance-Free Toner Cartridge
A toner cartridge can print up to 10,000 (Black) and 6,000 (Cyan,
Magenta and Yellow) single-sided pages at 5% coverage. The one
piece, easy-to-replace toner cartridges do not require difficult
maintenance.
Universal Media Cassette
This printer loads paper automatically from the media cassette. Since
the media cassette is a universal type, a number of different sizes of
paper can be used. Even envelopes can be loaded from the media
cassette.
Three Interfaces This printer has a high speed IEEE 1284 compliant bi-directional
parallel interface, an RS-232C serial interface, and a modular
input/output (MIO) compatible interface.
If the application software supports the bi-directional parallel interface,
you can monitor the printer status. It is fully compatible with the
industry-standard IEEE 1284 bi-directional parallel interface.
The RS-232C serial interface is an industry standard so that you can
connect it to any computer using a standard serial cable.
The MIO interface allows you to install a commercial MIO-compatible
card. If the card is installed, this interface port can be used for
features such as networking or printer sharing.

I-2
Automatic Interface Selection
The printer can automatically select the bi-directional parallel, RS-
232C serial, or MIO interface depending on the interface port through
which it receives data. With this feature, the printer can be connected
to more than one computer.
Five Emulation Modes
The printer can emulate Hewlett-Packard Color PCL®5C (PCL6®in
monochrome mode) and PostScript®Level 2 language emulation
(Brother BR-Script Level 2) printers, the industry-standard HP-GL™
plotter as well as EPSON®FX-850™, and IBM®Proprinter XL®printers
(in monochrome mode). It is possible to print with all application
programs that support one of these printers.
Automatic Emulation Selection
The printer can automatically select the printer emulation mode
depending on the print commands it receives from the computer
software. With this feature, many users can share the printer on a
network.
Data Compression Technology
The printer can internally compress the received graphics and font
data in its memory so that it can print larger graphics and more fonts
without additional memory.
Various Fonts The printer has 75 scalable fonts and 12 bitmapped fonts The fonts
that can be used vary according to the current emulation mode.
CCITT G3/G4 Since the printer supports the CCITT G3/G4 format in addition to HP-
compatible formats, it can quickly receive and print data compressed
in this format.
Lock Panel If the panel button settings have been changed, the printer may not
work as expected. It is possible for the administrator of the printer to
lock the settings to prevent changes from being made.
Power Save Mode
The printer has a power saving mode. As laser printers consume
power to keep the fixing assembly at a high temperature, this feature
can save electricity when the printer is on but not being used. The
factory setting of the Power Save mode is ON so that it complies with
the EPA Energy Star new specification. Compared with conventional
laser printers, this printer consumes less power even when the power
saving mode is turned off.
Toner Save ModeThe printer has an economical toner save mode. This mode allows
you to reduce the printer running cost substantially in addition to the
improved life expectancy of the toner cartridge.
Reprint Function A touch of a panel button allows reprinting of the last print job without
sending the data again from the computer. When there is not enough
memory to print the last complete job out, the last print page can be
reprinted.

I-3
PCMCIA Card Slot
The printer has two PCMCIA card slots (Type II cards: 2 slots
available, Type III cards: 1 slot available). The following cards can be
installed;
• PCMCIA-compatible flash memory card
• HDD card
• PCMCIA Fax Modem card
Saving User Settings
It is possible to operate the printer differently from other users with the
panel button settings. Two sets of user settings can be stored.

I-4
2. PARTS NAMES & FUNCTIONS
<Front View>
Fig.1-1
<Rear View>
Fig.1-2
1. Top Cover
2. Control Panel
4. Power Button
3. Front Cover
Media cassette
7. Controller Box
5. Power Inlet
6. Rear Access Cover

I-5
No. Part Name Outline of Functions
1 Top Cover To act as an upper enclosure and also as a
paper tray for printed paper.
2 Control Panel To display the status of printer operation.
3 Front Cover To act as a front enclosure, opened when
replacing a toner cartridge or waste toner pack.
4 Power Button To operate power-on and off to the printer.
(Push for On/Off operation)
5 Power Inlet To connect a power supply cable.
6 Rear Access Cover To act as a rear enclosure, opened when
clearing an internal jam or doing maintenance
work.
7 Controller Box Space where the main (video controller) PCB is
installed.