LASER PRINTER
LS-5 SERIES
TECHNICAL MANUAL
[SECOND EDITION]
NOTICE
• All rights reserved. Reproduction of any part of this manual in any
form whatsoever, without STAR’s express permission is forbidden.
• The contents of this manual are subject to change without notice.
• All efforts have been made to ensure the accuracy of the contents
of this manual at the time of going to press. However, should any
errors be detected, STAR would greatly appreciate being informed of them.
• The above notwithstanding, STAR can assume no responsibility
for any errors in this manual.
© Copyright 1992 Star Micronics Co.,Ltd.
INTRODUCTION
This manual is an introduction to the laser printer as shown below.
It is intended for use as a reference for maintenance procedures.
This manual is prepared for use at a technical level and not for the general user.
• LS-5EX
• LS-5TT
• LS-5
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2
This manual is divided into the following sections:
Chapter 1 General Specifications
Specifications, safety information
Chapter 2 Theory of Operation
A description of the principles of the electrical and mechanical systems and their functions
Chapter 3 Parts Replacement and Adjustments
Explanation of disassembly, reassembly, and adjustment procedures
Chapter 4 Maintenance Guide
Contains an overview of steps to assist in recovering from a breakdown, connector layout diagrams, wiring
connections, and other information helpful in maintenance operations.
Chapter 5 Troubleshooting
Contains breakdown analysis procedures used in repairing breakdowns.
Chapter 6 Parts List
Illustrations showing disassembly diagrams, part numbers, and part names
• First edition : Dec. 1992
Second edition : Feb. 1993 Add LS-5 model
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GENERAL SPECIFICATIONS
– 2 –
CHAPTER 1
GENERAL SPECIFICATIONS
1. General Specifications..........................................................................................3
2. Pin Functions on Interfaces .................................................................................5
2-1. Parallel Interface ..................................................................................................... 5
2-2. Serial Interface........................................................................................................ 5
2-3. AppleTalk Interface................................................................................................. 5
3. Safety Information.................................................................................................6
3-1. Power Supply.......................................................................................................... 6
3-2. Drive Parts............................................................................................................... 6
3-3. Safety Devices ........................................................................................................ 6
1
3-4. Laser safety............................................................................................................. 7
4. Printer Components..............................................................................................8
GENERAL SPECIFICATIONS
– 2 –
GENERAL SPECIFICATIONS
1. General Specifications
(1) Type Desk-top page printer
(2) Printing method Electro photography
(3) Printing speed 5 pages/min (A4 size)
3.56 pages/min (legal size)
(4) Time for first print 27 seconds or less
(5) Warm-up time 1 min or less (after power on until the printer warms up at ambient
temperature of 20°C with rated AC voltage input)
(6) Optical system
Laser Semiconductor laser beam
Scanning system Rotating scanning mirror
Scanning pitch
Horizontal 300 dots/inch
Vertical 300 rasters/inch
(7) Printing system
Photosensitive drum OPC
Exposure method Laser scanning system
Paper feed Cassette feed
Front paper tray feed
Fusing method Thermal fusing by heated rollers
Toner supply Included in replaceable EPX toner cartridge
(8) Paper feed sources
Standard 250-sheet deck with cassette
50-sheet front paper tray
Option 250-sheet deck with cassette
500-sheet deck with cassette
(9) Paper
250 universal cassette
Paper size Letter (8.5" × 11"), A4, Executive, B5
Capacity 250 sheets, or maximum 27 mm loading height
250 legal cassette
Paper size Legal 14" (8.5" × 14"), Letter (8.5" × 11")
Capacity 250 sheets
250 envelope cassette
Paper size COM-10, Monarch, DL, C5
Capacity 30 envelopes
500 letter cassette
Paper size Letter (8.5" × 11")
Capacity 500 sheets
500 A4 cassette
Paper size A4
Capacity 500 sheets
500 B5 cassette
Paper size B5
Capacity 500 sheets
Front tray
Paper size Letter (8.5" × 11"), A4, Envelopes
Capacity 50 sheets or 5 envelopes
(10) Paper weight (plain paper)
Front paper tray 60 g/m2 to 135 g/m
Cassette feed 60 g/m2 to 105 g/m
(11) Print delivery Face-down
2
2
– 3 –
GENERAL SPECIFICATIONS
(12) Acoustic noise (in accordance with ISO 7779)
Stand by 37 dB or less
Printing 45 dB or less
(13) Environment
Printer with EPX toner cartridge
Operating temperature 5°C to 35°C
Operating humidity 15% to 85%RH (without condensation)
Storage temperature –20°C to 40°C
Storage humidity 5% to 95% (without condensation)
Altitude 0 to 8200 feet (0 to 2500 meters)
Printer without EPX toner cartridge
Storage temperature –20°C to 60°C
Storage humidity 5% to 95% (without condensation)
Altitude 0 to 49200 feet (0 to 15000 meters)
(14) Power consumption
100 - 115V Max. 450W
220 - 240V Max. 500W
(15) Printable area The guaranteed printing requires a margin of 4 mm from each edge of the
paper.
(16) Dimensions (W × D × H) 352mm × 393.5 mm × 253mm
(17) Weight Approx. 12kg (without EPX toner cartridge)
(18) Line voltage Rating Range
Voltage 100 - 115V 90 to 132V
220 - 240V 198 to 264V
Frequency 50/60Hz 47Hz to 63Hz
(19) Host interface
LS-5EX
Parallel Centronics
Serial RS-232C
Optional AppleTalk (when an optional ROM board MS is installed)
LS-5TT
Parallel Centronics
Serial RS-232C
AppleTalk
LS-5
Parallel Centronics
Serial RS-232C/RS-422A
(20) RAM
Resident 1MB (LS-5EX)
2MB (LS-5TT)
0.5MB (LS-5)
Option Max. 6MB on RAM expansion board (LS-5EX/TT)
Max. 4MB on RAM expansion board (LS-5)
(21) Emulation
LS-5EX Standard: PCL5 and GL/2(HP Laserjet 3)
Option: TrueImage (with optional ROM board MS)
LS-5TT PCL5 and GL/2(HP Laserjet 3)
TrueImage (Apple LaserWriter NTX)
LS-5 PCL4 (HP LaserJet IIP)
ESC/P (Epson FX-286)
(22) Font
Resident 14 bitmap fonts
8 scalable fonts (LS-5EX/TT)
35 TrueType scalable fonts (LS-5TT only)
Option Font cartridge
– 4 –
GENERAL SPECIFICATIONS
2. Pin Functions on Interfaces
2-1. Parallel Interface
Pin No.
1 STROBE IN Goes from High to Low (for at least 0.5 microseconds) when data are valid.
2 DATA1 IN
3 DATA2 IN
4 DATA3 IN
5 DATA4 IN
6 DATA5 IN
7 DATA6 IN
8 DATA7 IN
9 DATA8 IN
10 ACK OUT A low pulse acknowledges receipt of data.
11 BUSY OUT Low when the printer is ready to receive data.
12 PAPER OUT OUT Goes High if the printer runs out of paper.
13 SELECTED OUT High when the printer is online.
14-15 N/C Unused
16
17
18 +5VDC OUT External supply of +5VDC
19-30 GND Twisted pair return signal ground level.
31 PRIM IN LS-5 model does not check this signal.
32 FAULT OUT Goes Low to signal that the printer cannot print due to an error condition.
33-36 N/C Unused. In case of LS-5 model, pin no. 33 and 35 are always HIGH.
Signal
Name
SIGNAL GND
CHASSIS GND
Direction Function
Eight-bit character data. DATA8 is the most significant bit; DATA1 is the least significant bit.
High is logic 1 and low is logic 0.
Signal ground
Printer’s chassis ground, isolated from signal ground.
LS-5EX and TT are not connected.
2-2. Serial Interface
Pin No.
1 GND 232C/422A Chassis ground
2 TXD OUT RS-232C Transmitted data
3 RXD IN RS-232C Received data
4 RTS OUT RS-232C SPACE when the printer is ready to receive data.
5-6 N/C Unused
7 GND 232C/422A Signal Ground
8 N/C Unused
9 TXD+ OUT RS-422A Transmitted data+
10 TXD– OUT RS-422A Transmitted data–
11-17 N/C Unused
18 RXD+ IN RS-422A Received data+
19 N/C Unused
20 DTR OUT RS-232C SPACE when the printer is ready to receive data.
21-25 N/C Unused
Signal
Name
RXD– IN RS-422A Received data–
Direction Interface Function
But this printer does not check the signal.
2-3. AppleTalk Interface
Pin No.
1 HSKo OUT Handshake out (always GND)
2 HSKi IN Handshake in
3 TXD– OUT Transmitted data –
4 GND Signal ground
5 RXD– IN Received data –
6 TXD+ OUT Transmitted data +
7 N/C Unused
8 RXD+ IN Received data +
Signal
Name
Direction Function
– 5 –
GENERAL SPECIFICATIONS
3. Safety Information
In order to prevent accidents from occurring while maintenance is being carried out, all warnings and precautions should
be strictly observed while working. Never attempt any kind of dangerous work when servicing this machine.
The precautions noted below are only a few of the situations which could foreseeably occur during maintenance
operations. Please make sure every safety precaution is observed while working.
3-1. Power Supply
In order to prevent electrical shock, burns, damage to the equipment, and other problems, always make sure the power
supply is turned off and the power supply cable has been unplugged before maintenance work is carried out.
If the power must be left on in order to measure voltage or for other reasons, make sure sufficient precautions are taken
to prevent electrical shock, and follow the procedures noted in this manual.
3-2. Drive Parts
Inspection of drive section parts such as sprockets and gears should be carried out using a hand crank.
DANGER: Never inspect these parts while the equipment is in operation!
3-3. Safety Devices
Thorough consideration should be given to safety devices designed to prevent accidents (fuses, interlock switches, etc.)
as well as those handled by the user in the course of operating the equipment (covers, panels, etc.), in order to make sure
they fulfill their function as safety equipment.
DANGER: In order to prevent exposure to the laser beam contained in the printer, the following precautions must always
be strictly observed.
Exposure to the laser beam can result in blindness.
• Never open cover (ROS assembly) that has the label of figure 1-2.
• When disassembling and adjusting the equipment, always make sure the power supply has been turned
off first.
• This equipment is provided with a two-stage safety switch function, so that it can be operated even with
the covers removed, by pressing the interlock switch. When using this method of operation, never short
the other switch at the same time (the second switch is pressed when the actuator at the back of the EPX
toner cartridge attachment section is pressed).
• When servicing the optical system of the printer, be careful not to place screwdrivers or other reflective
objects in the path of the laser beam.
Be sure to take off accessories, such as watches and rings, before working on the printer. A reflected beam,
though invisible, can permanently damage your eyes.
Because the laser beam is invisible, be especially careful when servicing the optical system.
– 6 –
GENERAL SPECIFICATIONS
3-4. Laser safety
This printer is certified as a Class 1 laser product. This means that this laser product does not emit harmful laser beams.
This printer emits a Class 3B laser beam, but the beam is entirely enclosed within a protective case and an external cover,
and cannot leak from the printer while the printer is in use.
CLASS 1 LASER PRODUCT.
LUOKAN 1 LASERLAITE.
KLASS 1 LASER APPARAT.
Figure 1-1 Class 1 Label
CLASS 3B LASER
WAVE LENGTH 780nm (INVISIBLE)
RATED POWER 5 m W
LUOKAN 3B LASER
AA LLON PIT UUS 780nm (NÄKYMÄTÖN)
TEHO 5m W
Figure 1-2 Caution Label
VARO! Avattaessa ja suojalukitus ohitettaessa olet alttiina näkymättömälle lasersäteilylle. Älä katso
säteeseen.
VARNING! Osynlig laserstrålning när denna del är öppnad och spärren är urkopplad. Betrakta ej strålen.
– 7 –
GENERAL SPECIFICATIONS
4. Printer Components
Figure 1-3 External Dimensions
Figure 1-5 Rear View Figure 1-6 Inside View
Figure 1-4 Front View
– 8 –
CHAPTER 2
THEORY OF OPERATION
1. Printing Process..................................................................................................11
2. Paper Transportation ..........................................................................................14
3. Functions of Main Parts......................................................................................15
3-1. Cassette Feed.......................................................................................................... 15
3-2. Paper Transportation .............................................................................................. 17
3-3. Fusing and Paper Exit............................................................................................. 19
3-4. Drive and Photographics........................................................................................ 20
3-5. Electrical .................................................................................................................. 22
2
THEORY OF OPERATION
– 10 –
THEORY OF OPERATION
1. Printing Process
The printing process of this system consists of repetition of the following basic seven steps:
Charging Scanning exposure Developing Transfer Separation Fusing Cleaning
The following schematic diagram will help to explain the printing process.
Figure 2-1 Printing Process
– 11 –
: Laser Beam
: Paper Path
THEORY OF OPERATION
• Descriptions of Printing Process
Process Contents
Charging The surface of the drum rotated by the BCR (bias charge roll) in the EPX toner cartridge
is negatively charged uniformly.
The ROS assembly converts image signals from the main logic board into optical signals
(laser beam), the laser beam scanning on the drum enabling exposure.
Scanning Exposure When an image is present, a laser is emitted. The laser beam is irradiated on the drum
surface, the negative charge of irradiated portions moves to the earth, thus enabling an
invisible electrostatic latent image to be formed on the drum surface.
The electrostatic latent image on the drum surface attracts toner on the magnetic roll surface
in the EPX toner cartridge, which is developed into a visible image on the drum surface.
Developing The toner is magnetic component. The magnet inside the magnetic roll causes the toner to
adhere to the roll, and the friction between the magnetic roll as it rotates and the CM
blade(Charge Metal Blade:the blade which charges the toner) converts the toner to a
negative charge, so that a thin layer of toner is formed on the surface of the magnetic roll.
The positive charge is impressed from the back of paper by the BTR (Bias Transfer Roll)
of the BTR assembly, thereby enabling toner on the drum surface to be transferred on the
paper.Transfer
Impressing plus charge from the back of paper causes the paper itself to be electrically
charged plus to adhere to the drum.
Separation
Fusing
Cleaning
Drum’s Surface
Voltage
The eliminator of the trans. chute assembly causes electric charge of the paper to flow to the
earth to weaken the adhesion to the drum of the paper, and the flexibility of the paper enables
the paper together with transferred toner to be separated from the drum.
Toner on the paper is fused on it in the fuser assembly by means of heat of the heat roll with
the heater rod as a heat source and pressure of the pressure roll.
Part of toner not transferred on the paper during transfer remains on the drum. This residual
toner is scraped away by the cleaning blade in contact with the drum surface.
Charging Scanning Exposure Developing
Laser Beam
–V
Electrostatic Latent
Image (Invisible Image)
–V
–360V
0
0
–360V
–V
Toner Image
(Visible Image)
–360V
–270V
(Developing Bias)
0
Figure 2-2 Printing Process (Drum’s Surface)
– 12 –
Pressure Roll
THEORY OF OPERATION
(φ19.65mm)
Fusing
(φ19.65mm)
Paper
Eliminator
Separation
Transfer
BTR
DC Bias
(+): 1.5µA (1000V)
(–): –600V
Magnetic Roll
Toner
Cleauing
Drum
(φ30mm)
Heat Roll
Stand by: 150°C
Printing: 160°C
Cleaning Blade
BCR
Charging
Laser Beam
Scanning Exposure
Toner
CM Blade
Developing
AC Bias: 1.6kVp-p (f=2.4kHz)
AC Bias: 200µA
(f=150Hz)
DC Bias: –360V
DC Bias: –270V
Figure 2-3 Printing Process (Seven Steps)
– 13 –
THEORY OF OPERATION
2. Paper Transportation
Paper transportation by the rolls is shown sequentially as follows:
Cassette feed Multi-purpose tray feed
Feed by the feed roll Feed by the pick up roll of the pick up roll assembly
Paper transportation by the turn roll of the turn roll
assembly and the pinch roll of the paper cassette
Paper transportation by the take away roll of the take away roll assembly and the pinch roll of the pick up
roll assembly
Paper transportation by the drum and the BTR of the BTR assembly
Paper transportation by the heat roll and the pressure roll
Paper exit by the exit roll of the exit roll assembly and the pinch roll of the fuser cover assembly
Figure 2-4 Paper Transportation
– 14 –
: Laser Beam
: Paper path
THEORY OF OPERATION
3. Functions of Main Parts
The following are brief descriptions with corresponding illustrations of the main parts. They are divided into the following
five blocks according to their architecture:
1. Cassette Feed
2. Paper Transportation
3. Fusing and Paper Exit
4. Drive and Photographics
5. Electrical
3-1. Cassette Feed
[1] Paper Cassette:
A cassette to hold cut sheets of paper.
Aligning the paper guide in the rear side to the paper causes the cam in the right rear to rotate, thereby changing the
location where the size spring is pressed.
A pinch roll corresponding to the turn roll of the turn roll assembly is also mounted.
[2] Feeder PCB (PCB: Printed Circuit Board):
The paper size switch and the no paper sensor are directly mounted on the board, the former detecting the cassette
paper size and the presence of the paper cassette with a combination of ON and OFF operations of the switches
according to the changes in the location of the size spring and the latter detecting the presence of sheets of paper in
the paper cassette.
With the no paper sensor, the state of the presence of sheets of paper being not detected shall be OFF.
[3] Feed Solenoid:
Controls operations (rotation and stop) of the feed roll assembly.
[4] Feed roll assembly:
Comprises a feed roll and feed clutch assemblies. When the feed solenoid is actuated, the spring clutch of the feed
clutch assembly becomes fixed, the feed roll assembly rotates by the drive from the drive assembly, the feed roll
delivering sheets of the paper from the cassette.
One full rotation of the feed roll assembly causes the spring clutch to be released, thus disabling the drive of the drive
assembly from being transmitted.
[5] Turn Solenoid:
Controls operations (rotation and stop) of the turn roll assembly (only when it receives PRFD (prefeed) signals from
the main logic board).
[6] Turn Roll Assembly:
When receiving a PRFD (prefeed) signal from the main logic board, the turn solenoid is actuated to cause the spring
clutch of the turn roll assembly to be released, thus stopping transmission of the drive from the drive assembly and
paper transportation, allowing the turn roll assembly to wait in front of the regi. sensor.
The turn solenoid,on receiving a START signal from the main logic board, stops operating to cause the spring clutch
to be fixed, the turn roll assembly rotating by the drive from the drive assembly to deliver sheets of paper.
When receiving no PRFD signal, the turn roll assembly is constantly transmitted the drive from the drive assembly
to deliver sheets of paper.
– 15 –
THEORY OF OPERATION
Figure 2-5 Cassette Feed
– 16 –
THEORY OF OPERATION
3-2. Paper Transportation
[1] MBF Sensor (MBF: Multi-sheet Bypass Feed):
Detects the presence of sheets of paper in the multi-purpose tray (front tray assembly) according to change in the
position of MBF actuator. It assumes ON state when the presence of the paper is being detected.
[2] Pick up Solenoid:
Controls operations (rotation and stop) of the pick up roll assembly.
[3] Pick up Roll Assembly:
Activation of the pick up solenoid causes the spring clutch of the pick up roll assembly to be fixed and rotate due to
the drive from the drive assembly, causing the cam of the pick up roll assembly to operate the bottom plate assembly
vertically, thus the pick up roll of the pick up roll assembly delivering sheets of paper from the multi-purpose tray
(front tray assembly).
One full rotation of the pick up roll assembly causes the spring clutch to be released, thus disabling the drive from
the drive assembly from being transmitted.
A pinch roll corresponding to the take away roll of the take away roll assembly is also mounted.
[4] Inlet Chute Assembly:
Comprises an inlet chute and a regi. sensor.
• Inlet Chute:
Not only serves as a paper path but moves the electrical charge of pretransfer sheets of paper to the earth by a
metallic plate, improving transfer efficiency.
• Regi. Sensor (Regi.: Registration):
Detects the state of paper transportation in the inlet chute area. It assumes ON state when the presence of the paper
is being detected.
[5] BTR Assembly (BTR: Bias Transfer Roll):
The BTR, a component, comes into contact with the EPX toner cartridge drum, impresses the positive electrical
charge from the back of sheets of paper, thus transferring toner on the drum surface on them.
[6] Trans. Chute Assembly (Trans.: Transport):
It not only serves as a paper transport path but moves to the earth the electrical charge of post-transfer sheets of paper
and that from the BTR by means of the eliminator.
[7] Console Assembly:
Performs various display by means of the LCD and various inputs with the key switch.
[8] Lower Chute Assembly:
Comprises a take away roll assembly and a retard pad assembly.
• Take Away Roll Assembly:
Transports sheets of paper to the drum by the take away roll of the take away roll assembly.
• Retard Pad Assembly:
Prevents duplicate paper transportation during paper delivery by the pick up roll assembly.
[9] Link Assembly:
Not only regulates the opening of the front cover assembly but depresses the interlock switch of the LVPS assembly
when the front cover assembly is closed, opening the drum shutter of the EPX toner cartridge.
– 17 –
THEORY OF OPERATION
Figure 2-6 Paper Transportation
– 18 –
THEORY OF OPERATION
3-3. Fusing and Paper Exit
[1] Fuser Assembly:
Comprising a heater rod, heat roll, pressure roll, temp. sensor assembly, thermostat and fuse, it fuses, on a sheet of
paper, toner transferred on it by heat and pressure.
The items related to the fuser assembly are referred to as fuser.
• Heater Rod:
A lamp with a heated coil sealed in it, located inside of the heat roll, serving as a heat source of the heat roll.
• Heat Roll:
Provides heat for fusing toner on sheets of paper.
• Pressure Roll:
Provides pressure for applying toner on sheets of paper.
• Temp. Sensor Assembly (Temp.: Temperature):
Detects surface temperature of the heat roll with which the thermistor (electric resistor to react with temperature
change) is in contact.
Based on surface temperature of the heat roll thus detected, it controls ON/OFF operations of the heater rod and
prevents excessive rise in primary temperature.
• Thermostat:
In series with the power supply of the heater rod, it prevents excessive rise in secondary temperature through
opening of the contact resulted when secondary temperature reaches the constant ambient temperature if the
preventive function by the thermistor against excessive rise in temperature (primary) fails.
• Fuse:
This is inserted next to the power supply of the heater rod. If a problem occurs such as overheating caused by the
thermistor(primary)and then by the thermostat(secondary), the fuse melts when the ambient temperature reaches
a certain level, to prevent tertiary overheating.
[2] Exit Sensor:
Detects the state of printing paper transportation in the exit area.
The state of printing paper being detected shall be ON.
Figure 2-7 Fusing and Paper Exit
– 19 –
THEORY OF OPERATION
3-4. Drive and Photographics
[1] Drive Assembly:
Comprises a main motor and gears to transmit its drive, providing mechanical drive by rotation of the main motor.
[2] ROS Assembly (ROS: Raster Output Scanner):
Comprises an LD assembly, scanner assembly, SOS PCB, lens, mirror and window. The items related to the ROS
assembly are referred to as ROS.
• LD Assembly (LD: Laser Diode):
Converts electric signals into a laser beam, emitting light.
Power of a laser diode (LD power) is controlled to be constant through the monitor circuit.
• Scanner Assembly:
A polygon mirror with six specular surfaces is mounted on the scanner motor to rotate at a constant speed. The
rotation of the polygon mirror causes angles of incidence and reflection of a laser beam to change, one surface of
the polygon mirror scanning one line in direction of the drum axis.
A laser beam reflected by the polygon mirror is irradiated on the drum surface via the lens, mirror and window.
• SOS PCB (SOS: Start Of Scan):
The irradiation of a laser beam on the SOS sensor causes the laser beam to be converted into an electric signal(SOS
signal), thereby detecting the initial scanning location of one line.
[3] CRU Sensor PCB (CRU: Customer Replaceable Unit):
Comprises a CRU switch and LD switches which are turned ON and OFF by the CRU actuator assembly, the former
detecting the presence of the EPX toner cartridge and the latter, in series with the circuit emitting a laser beam,
securing the safety for a laser beam.
[4] EPX Toner Cartridge (EP: Electrical Photographics):
Comprises a drum, BCR, magnetic roll, CM blade and cleaning blade.
• Drum:
Comprises an aluminum cylinder on which an OPC (Organic Photo Conductor) sensitive material with photoconductivity (a quality to retain the electrical charge in the darkness and move it to the earth by light) is deposited,
producing a printed image according to the potential difference (electrostatic latent image) of the surface.
• BCR (Bias Charge Roll):
Enables the drum surface to be electrically charged uniformly.
• Magnetic Roll:
Supplies toner to the drum for developing an electrostatic latent image on the drum surface.
• CM Blade (CM: Charge Metal):
Not only makes homogeneous the amount of toner on the magnetic roll surface but gives toner the electrical charge
by means of friction.
• Cleaning Blade:
Scratches off residual toner on the post-transfer drum surface, cleaning it.
– 20 –
Figure 2-8 Drive
THEORY OF OPERATION
Figure 2-9 ROS Assy
Figure 2-10 EPX Toner Cartridge
– 21 –
THEORY OF OPERATION
3-5. Electrical
[1] LVPS Assembly (LVPS: Low Voltage Power Supply):
Not only supplies AC power to the heater rod but produces and supplies stable DC power with low voltage to be used
in the logic circuit, etc.
It includes an interlock switch and a main power switch, the former being a safety switch to make or break the circuits
for AC power and DC power with a low voltage of 24 V from other than the fan power supply by depressing and
releasing the switch of the front cover assembly and the latter being the main power switch for turning ON and OFF
the power.
[2] HVPS (high voltage power supply):
Supplies voltage and current to the BCR, BTR and magnetic roll for charging, developing and transfer.
[3] MCU PCB (Main Control Unit):
Controls the whole printing operations based on information from the sensors and communication with the main logic
board.
Its main functions are as follows:
• Communication with the main logic board;
• Reception of information from the sensors and switches;
• Control of the ROS, fuser and drive assemblies;
• Control of the printing sequence;
• Distribution of low-voltage DC power from the LVPS assembly to each component.
[4] Fan:
Exhausts the system, thereby preventing internal temperature from increasing.
Figure 2-11 Electrical
– 22 –
CHAPTER 3
3
REPLACEMENT AND ADJUSTMENTS OF PARTS
This chapter explains adjustment, disassembly and reassembly of the printer. The following precautions
should be noted during disassembly and reassembly:
1. Disconnect the printer from the wall outlet before servicing it.
2. Unless otherwise specified, the printer is assembled by reversing the disassembly procedure.
3. Do not operate the printer with any parts removed.
4. When you remove the EPX toner cartridge, be sure to keep the cartridge in its original box. If the box is
not available, cover the cartridge with a cloth or put it in a dark place to prevent light from affecting the
drum inside the cartridge.
1. Covers ......................................... 25
1-1. Rear Cover..............................25
1-2. Top Cover Assembly.............25
1-3. Left Cover and Right Cover ..26
2. Cassette Feed ............................. 27
2-1. Feeder Assembly...................27
2-2.
2-3. Feed Roll Assembly...............28
2-4. Feed Rolls...............................28
2-5. Turn Roll Assembly...............29
2-6. No Paper Actuator .................29
2-7. Feeder PCB ............................30
2-8. Size Spring .............................30
Feed Solenoid and Turn Solenoid..
27
3. Paper Transportation ................. 31
3-1. Link Assembly .......................31
3-2. Gear Double L ........................32
3-3. Gear Double R........................32
3-4. Lower Chute Assembly.........33
3-5. Take Away Roll Assembly .... 33
3-6. Front Cover Assembly ..........34
3-7. BTR Assembly .......................35
3-8. Trans. Chute Assembly.........35
3-9. Inlet Chute Assembly ............36
3-10. Regi. Sensor...........................36
3-11. Front Plate Assembly ............37
3-12. Pick Up Roll Assembly..........37
3-13. Pick Up Solenoid ...................38
3-14. MBF Sensor Assembly..........38
3-15. MBF Sensor............................39
3-16. Bottom Plate Assembly.........39
3-17. Console Assembly.................40
4. Fusing & Paper Exit ................... 41
4-1. Fuser Assembly .....................41
4-2. Pressure Roll..........................41
4-3. Exit Chute ...............................42
4-4. Exit Roll Assembly ................42
4-5.
Temperature Sensor Assembly ..
4-6. Heater Rod..............................43
4-7. Heat Roll .................................44
4-8. Exit Actuator ..........................44
4-9. Exit Sensor .............................44
43
5. Drive & Electrical........................ 45
5-1. Drive Assembly......................45
5-2. CRU Sensor PCB ...................45
5-3. CRU Actuator Assembly .......46
5-4. ROS Assembly .......................46
5-5. ESS Assembly........................47
5-6. Main Logic Board...................47
5-7. Electrical Box Cover..............48
5-8. Earth Plate Assembly ............48
5-9. MCU PCB ................................49
5-10. HVPS .......................................49
5-11. LVPS Assembly .....................50
5-12. Fan ..........................................50
REPLACEMENT AND ADJUSTMENTS OF PARTS
– 24 –
REPLACEMENT AND ADJUSTMENTS OF PARTS
1. Covers
1-1. Rear Cover
(1) Turn off the power switch and disconnect the power
cord from the wall outlet.
(2) Pressing down on the two latches [1] on the top of the
rear cover [2], open the rear cover [2].
(3) Pressing down on the two latches [3] on the bottom
of the rear cover [2], pull the rear cover [2] and
remove it.
1-2. Top Cover Assembly
(1) Open the rear cover according to the procedure
described in section 1-1.
(2) Open the front cover assembly [1].
(3) Remove the three screws [2] securing the top cover
assembly [3].
(4) Lift up the left side of the top cover assembly [3], and
remove the section [5] latching the top cover assembly [3] and the right cover [4].
Note:Use a mini-screwdriver or similar tool to
remove the latched section [5].
(5) Lift up the back of the top cover assembly [3], and,
with the left front side at the center, rotate the top
cover assembly approximately 15 degrees in the
counterclockwise direction.
(6)
Lift up the entire top cover assembly [3] and remove
it.
Note: When the entire top cover assembly [3] is
lifted up, the section [7] latching the left cover
[6] and top cover assembly [3] becomes
– 25 –
detached.
REPLACEMENT AND ADJUSTMENTS OF PARTS
1-3. Left Cover and Right Cover
(1) Remove the top cover assembly according to the
procedure described in section 1-2.
(2) Remove the left cover [1] by removing the latched
section [2].
(3) Remove the right cover [3] by removing the latched
section [4].
Note: When removing the latched section, use a
mini-screwdriver or similar tool.
– 26 –
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