Samsung ML-4551NDR, ML-4551NR, ML-4551ND, ML-4550, ML-4551N Service Manual

DIGITAL LASER PRINT
ML-4550 Series

ML-4550 / ML-4551N / ML-4551ND

ML-4551NR / ML-4551NDR

Basic Model :ML-4550

Manual

SERVICE

DIGITAL LASER PRINT CONTENTS

[The keynote of Product]

- Series Model: ML-4550 / 4551N / 4551ND

- High speed Laser Printer:
Up to 43 ppm in A4 (45 ppm in Letter),
Duplex: 29 ipm (A4); 30 ipm (Letter)

- Resolution: Up to 1200 x 1200 dpi

- Marvell 500Mhz

- Memory: 128 MB (Max. 512 MB)
128, or 256 MB optional memory available.
Use only the Samsung-approved DIMM.
128 MB: ML-MEM150, 256 MB: ML-MEM160

- Option:
ML-4550:500-sheet trays, ethernet 10/100 Base
TX wired LAN, ethernet 10/100 Base
hard disk, duplex unit, DIMM

- Toner cartridge:

Starter: 10K or 20K pages
Consumable: 10K or 20K pages

- Duty cycle: Monthly Up to 150,000 pages

Contents

1. Precautions

1.1 Safety Warning 1-1

1.2 Caution for safety

1.2.1 Toxic material

1.2.2 Electric Shock and Fire Safety Precautions

1.2.3 Handling Precautions

1.2.4 Assembly / Disassembly Precautions

1.2.5 Disregarding this warning may cause bodily injury

1.3 ESD Precautions

2. Product Specifications

2.1 Product Overview 2-1

2.2 Specifications

2.2.1 General Specifications

2.2.2 Controller & S/W

2.2.3 Paper Handling

2.2.4 Consumables

2.2.5 Reliability & Service

2.2.6 Environment

2.2.7 Options

2.2.8 Others

2.3 Model Comparison Table

1-2
1-2

1-2
1-3

1-3
1-4

1-5

2-1
2-1
2-2

2-3
2-4

2-4
2-4

2-5
2-5

2-6

3. Summary of Product

3.1 Printer Components 3-1

3.1.1 Front View

3.1.2 Rear View

3.1.3 Control Panel

3.2 System Layout

3.2.1 Feeding

3.2.2 Transfer

3.2.3 Driver Ass'y

3.2.4 Fuser

3.2.5 LSU (Laser Scanner Unit)

3-1

3-2
3-3

3-7
3-8

3-9
3-9

3-9
3-9

Continue...

3.2.6 Print Cartridge 3-10

3.3 Engine H/W Specifications

3.3.1 ML-4550 (PCL) Main Board

3.3.2 SMPS & HVPS board

3.3.3 Engine F/W

4. Alignment and Adjustments

4.1 How to use EDC (Engine Diagnostic Control) Mode 4-1

4.1.1 EDC Setup

4.1.2 Entrance method for EDC

4.1.3 Cover Status

4.1.4 Sensor Status

4.1.5 Motor Test

4.1.6 Fan Test

4.1.7 Clutch / Sol

4.1.8 Fuser Ctrl

4.1.9 LSU

4.1.10 Deve Control

4.1.11 Print Test and Option version

4.2 Paper Path

4.2.1 Clearing Paper Jams

4.3 Sample Pattern

4.3.1 Information Pages

4.3.2 Demo Pages

4.4 Periodic Defective Image

4.5 Error Messages

3-11

3-11
3-16
3-20

4-1

4-1
4-2

4-3
4-5

4-5
4-6
4-7

4-7
4-8

4-9
4-10

4-12
4-17

4-17
4-17

4-18
4-19

5. Disassembly and Reassembly

5.1 General Precautions on Disassembly 5-1

5.2 Transfer Roller

5.3 MPF Ass’y

5.4 Holder Pad Ass'y

5.5 Retard Ass'y

5.6 Feed2 Idle Unit

5.7 Cover Right

5-2

5-3

5-4

5-5

5-6

5-7

Continue...

5.8 Main PBA 5-8

5.9 Main Drive Ass'y

5.10 DEVE Drive Ass'y

5.11 Connector PBA

5.12 Solenoid

5.13 Rear Cover

5.14 Cover Left

5.15 Top Cover

5.16 Open Cover

5.17 Inner Cover

5.18 Fuser Ass'y

5.19 Duplex Solenoid Ass'y

5.20 Exit Roller

5.21 LSU

5.22 DC Fan

5.23 Toner Sensor PBA

5.24 REGI Ass'y

5.25 MP Pick Up Ass'y

5.26 Pick Up & Feed2 Assy

5.27 Engine Shield

5-9

5-10

5-11
5-12

5-13
5-14

5-15
5-16

5-17
5-18

5-20
5-21

5-22
5-23

5-24
5-25
5-26

5-28
5-31

6. Troubleshooting

6.1 The cause and solution of Bad image 6-1

6.2 The cause and solution of the bad discharge

6.3 The cause and solution of the malfunction

6.4 Maintaining the toner cartridge

6.5 The cause and solutions of bad environment of the software

7. Exploded Views & Parts List

7.1 Main Assembly 7-2

7.2 Cover Assembly

7.3 Frame Assembly

7.4 Fuser Unit

7.5 REGI Assembly

6-8

6-13
6-17

6-22

7-5

7-7
7-12

7-14

Continue...

7.6 Main Motor Assembly 7-16

7.7 Deve Motor Assembly

7.8 Exit Sorenoid Assembly

7.9 Cassette Assembly

7.10 Duplex Unit

7.11 SCF Unit

8. Block diagram

8.1 System Block Diagram 8-1

9. Connection Diagram

9.1 Connection Diagram 9-1

7-18

7-20

7-22

7-24

7-26

10. Schematic Diagram

10.1 Main Board 10-1

10.2 DIMM board

10.3 CRUM board

10.4 EMPTY board

10.5 HVPS

10.6 Panel

10.7 SCF

10.8 Toner sensor

10.9 HDD.eps

11. Reference Information

11.1 Troubleshooting Tools 11-1

11.2 Acronyms and Abbreviations

11.3 Select a location for the printer

11.4 Sample Tests Patterns

10-17

10-19
10-20

10-21
10-25

10-26
10-29

10-30

11-2

11-4

11-5

1. Precautions

CAUTION - INVISIBLE LASER RADIATION

WHEN THIS COVER OPEN.
DO NOT OPEN THIS COVER.

VORSICHT - UNSICHTBARE LASERSTRAHLUNG,

WENN ABDECKUNG GE FFNET.
NICHT DEM STRAHL AUSSETZEN.

ATTENTION - RAYONNEMENT LASER INVISIBLE EN CAS

D OUVERTURE. EXPOSITION DANGEREUSE
AU FAISCEAU.

ATTENZIONE - RADIAZIONE LASER INVISIBILE IN CASO DI

APERTURA. EVITARE L ESPOSIZIONE AL
FASCIO.

PRECAUCION - RADIACION LASER IVISIBLE CUANDO SE ABRE.

EVITAR EXPONERSE AL RAYO.

ADVARSEL. - USYNLIG LASERSTR LNING VED BNING, N R

SIKKERHEDSBRYDERE ER UDE AF FUNKTION.
UNDG UDSAETTELSE FOR STR LNING.

ADVARSEL. - USYNLIG LASERSTR LNING N R DEKSEL

PNES. STIRR IKKE INN I STR LEN.

UNNG EKSPONERING FOR STR LEN.

VARNING - OSYNLIG LASERSTR LNING N R DENNA DEL

R PPNAD OCH SP RREN R URKOPPLAD.

BETRAKTA EJ STR LEN. STR LEN R FARLIG.

VARO! - AVATTAESSA JA SUOJALUKITUS OHITETTAESSA

OLET ALTTIINA N KYM TT M LLE LASER­S TEILYLLE L KATSO S TEESEEN.

In order to prevent accidents and to prevent damage to the equipment please read the precautions listed
below carefully before servicing the printer and follow them closely.

1

1

1.1 Safety Warning

(1) Only to be serviced by appropriately qualified service engineers.

High voltages and lasers inside this product are dangerous. This printer should only be serviced by a suitably
trained and qualified service engineer.

(2) Use only Samsung replacement parts

There are no user serviceable parts inside the printer. Do not make any unauthorized changes or
additions to the printer, these could cause the printer to malfunction and create electric shock or fire hazards.

(3) Laser Safety Statement

The Printer is certified in the U.S. to conform to the requirements of DHHS 21 CFR, chapter 1 Subchapter J for
Class 1(1) laser products, and elsewhere, it is certified as a Class I laser product
conforming to the requirements of IEC 825. Class I laser products are not considered to be hazardous. The
laser system and printer are designed so there is never any human access to laser radiation above a Class I
level during normal operation, user maintenance, or prescribed service condition.

Precautions

Warning >> Never operate or service the printer with the protective cover removed from Laser/Scanner assembly. The

reflected beam, although invisible, can damage your eyes. When using this product, these basic safety
pre-cautions should always be followed to reduce risk of fire, electric shock, and injury to persons.

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1-1

Precautions

1.2 Caution for safety

1.2.1 Toxic material

This product contains toxic materials that could cause illness if ingested.

(1) If the LCD control panel is damaged it is possible for the liquid inside to leak. This liquid is toxic. Contact with the skin

should be avoided, wash any splashes from eyes or skin immediately and contact your doctor. If the liquid gets into
the mouth or is swallowed see a doctor immediately.

(2) Please keep toner cartridges away from children. The toner powder contained in the toner cartridge may be harmful

and if swallowed you should contact a doctor.

1.2.2 Electric Shock and Fire Safety Precautions

Failure to follow the following instructions could cause electric shock or potentially cause a fire.

(1) Use only the correct voltage, failure to do so could damage the printer and potentially cause a fire or electric

shock.

(2) Use only the power cable supplied with the printer. Use of an incorrectly specified cable could cause the cable

to overheat and potentially cause a fire.

(3) Do not overload the power socket, this could lead to overheating of the cables inside the wall and could lead to

a fire.

(4) Do not allow water or other liquids to spill into the printer, this can cause electric shock. Do not allow paper

clips, pins or other foreign objects to fall into the printer these could cause a short circuit leading to an electric
shock or fire hazard..

(5) Never touch the plugs on either end of the power cable with wet hands, this can cause electric shock. When

servicing the printer remove the power plug from the wall socket.

(6) Use caution when inserting or removing the power connector. The power connector must be inserted com-

pletely otherwise a poor contact could cause overheating possibly leading to a fire. When removing the power
connector grip it firmly and pull.

(7) Take care of the power cable. Do not allow it to become twisted, bent sharply round corners or other wise

damaged. Do not place objects on top of the power cable. If the power cable is damaged it could overheat and
cause a fire or exposed cables could cause an electric shock. Replace a damaged power cable immediately,
do not reuse or repair the damaged cable. Some chemicals can attack the coating on the power cable,
weakening the cover or exposing cables causing fire and shock risks.

(8) Ensure that the power sockets and plugs are not cracked or broken in any way. Any such defects should be

repaired immediately. Take care not to cut or damage the power cable or plugs when moving the machine.

(9) Use caution during thunder or lightening storms. Samsung recommends that this machine be disconnected

from the power source when such weather conditions are expected. Do not touch the machine or the power
cord if it is still connected to the wall socket in these weather conditions.

(10) Avoid damp or dusty areas, install the printer in a clean well ventilated location. Do not position the machine

near a humidifier. Damp and dust build up inside the machine can lead to overheating and cause a fire.

(11) Do not position the printer in direct sunlight. This will cause the temperature inside the printer to rise possibly

leading to the printer failing to work properly and in extreme conditions could lead to a fire.

(12) Do not insert any metal objects into the machine through the ventilator fan or other part of the casing, it could

make contact with a high voltage conductor inside the machine and cause an electric shock.

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Precautions

1.2.3 Handling Precautions

The following instructions are for your own personal safety, to avoid injury and so as not to damage the printer

(1) Ensure the printer is installed on a level surface, capable of supporting its weight. Failure to do so could cause

the printer to tip or fall.

(2) The printer contains many rollers, gears and fans. Take great care to ensure that you do not catch your fingers,

hair or clothing in any of these rotating devices.

(3) Do not place any small metal objects, containers of water, chemicals or other liquids close to the printer which if

spilled could get into the machine and cause damage or a shock or fire hazard.

(4) Do not install the machine in areas with high dust or moisture levels, beside on open window or close to a

humidifier or heater. Damage could be caused to the printer in such areas.

(5) Do not place candles, burning cigarettes, etc on the printer, These could cause a fire.

1.2.4 Assembly / Disassembly Precautions

Replace parts carefully, always use Samsung parts. Take care to note the exact location of parts and also
cable routing before dismantling any part of the machine. Ensure all parts and cables are replaced correctly.

Please carry out the following procedures before dismantling the printer or replacing any parts.

(1) Check the contents of the machine memory and make a note of any user settings. These will be erased if the

mainboard or network card is replaced.
(2) Ensure that power is disconnected before servicing or replacing any electrical parts.
(3) Disconnect printer interface cables and power cables.

(4) Only use approved spare parts. Ensure that part number, product name, any voltage, current or temperature

rating are correct.
(5) When removing or re-fitting any parts do not use excessive force, especially when fitting screws into plastic.

(6) Take care not to drop any small parts into the machine.
(7) Handling of the OPC Drum

- The OPC Drum can be irreparably damaged if it exposed to light.
Take care not to expose the OPC Drum either to direct sunlight or to fluorescent or incandescent room
lighting. Exposure for as little as 5 mins can damage the surface’s photoconductive properties and will result
in print quality degradation. Take extra care when servicing the printer. Remove the OPC Drum and store it in
a black bag or other lightproof container. Take care when working with the covers(especially the top cover)
open as light is admitted to the OPC area and can damage the OPC Drum.

- Take care not to scratch the green surface of OPC Drum Unit.
If the green surface of the Drum Cartridge is scratched or touched the print quality will be compromised.

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Service Manual

1-3

Precautions

1.2.5 Disregarding this warning may cause bodily injury

(1) Be careful with the high temperature part.

The fuser unit works at a high temperature. Use caution when working on the printer. Wait for the fuser to cool
down before disassembly.

(2) Do not put finger or hair into the rotating parts.

When operating a printer, do not put hand or hair into the rotating parts (Paper feeding entrance, motor, fan,
etc.). If do, you can get harm.

(3) When you move the printer.

This printer weighs 22kg including toner cartridge and cassette. Use safe lifting and handling techniques. Use
the lifting handles located on each side of the machine. Back injury could be caused if you do not lift carefully.

(4) Ensure the printer is installed safely.

The printer weighs 22Kg, ensure the printer is installed on a level surface, capable of supporting its weight.
Failure to do so could cause the printer to tip or fall possibly causing personal injury or damaging the printer.

(5) Do not install the printer on a sloping or unstable surface. After installation, double check that the printer is stable.

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Precautions

1.3 ESD Precautions

Certain semiconductor devices can be easily damaged by static electricity. Such components are commonly called
“Electrostatically Sensitive (ES) Devices”, or ESDs. Examples of typical ESDs are: integrated circuits, some field
effect transistors, and semiconductor “chip” components.

The techniques outlined below should be followed to help reduce the incidence of component damage caused by
static electricity.

Caution >>Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.

1. Immediately before handling a semiconductor component or semiconductor-equipped assembly, drain off any
electrostatic charge on your body by touching a known earth ground. Alternatively, employ a commercially avail­able wrist strap device, which should be removed for your personal safety reasons prior to applying power to the
unit under test.

2. After removing an electrical assembly equipped with ESDs, place the assembly on a conductive surface, such as
aluminum or copper foil, or conductive foam, to prevent electrostatic charge buildup in the vicinity of the assem­bly.

3. Use only a grounded tip soldering iron to solder or desolder ESDs.

4. Use only an “anti-static” solder removal device. Some solder removal devices not classified as “anti-static” can
generate electrical charges sufficient to damage ESDs.

5. Do not use Freon-propelled chemicals. When sprayed, these can generate electrical charges sufficient to dam­age ESDs.

6. Do not remove a replacement ESD from its protective packaging until immediately before installing it. Most
replacement ESDs are packaged with all leads shorted together by conductive foam, aluminum foil, or a compa­rable conductive material.

7. Immediately before removing the protective shorting material from the leads of a replacement ESD, touch the pro­tective material to the chassis or circuit assembly into which the device will be installed.

8. Maintain continuous electrical contact between the ESD and the assembly into which it will be installed, until com­pletely plugged or soldered into the circuit.

9. Minimize bodily motions when handling unpackaged replacement ESDs. Normal motions, such as the brushing
together of clothing fabric and lifting one’s foot from a carpeted floor, can generate static electricity sufficient to
damage an ESD.

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1-5

2. Product Specifications

2

2

2.1 Product Overview

Item Descriptions Remark

Basic Model ML-4550

Series Model ML-4550, ML-4551N, ML-4551ND, ML-4551NDG(Kor.)

Maket of Sailes Office user Laser printer. (Network for work Group)

Specification

43ppm(Ltr. 45ppm), 500MHz Processor, 128MB Memory

10K(initial), 20K(sailes)

USB(Hight Speed USB 2.0), Network Option,
ML-4551N, ML-4551ND(Network base)

Face Down(250 sheets), Face Up(100 sheets)

Specifications

2.2 Specifications

Product Specifications are subject to without notice. See below for product specifications.

2.2.1 General Specifications

ITEM ML-4550 SERIES

ML-4550 ML-4551N ML-4551ND

Engine Speed Simplex Up to 43 ppm in A4 (45 ppm in Letter)

Duplex Option : 29 ipm in A4 (30 ipm in Letter)

Warmup time - Less than 45 sec : Power-on boot
FPOT From Ready Less than 8.5 sec

From Idle Less than 43.5 sec
From Coldboot

Resolution - Up to 1200 x 1200 dpi effective output

Less than 53.5 sec

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Specifications

2.2.2. Controller & S/W

ITEM ML-4550 SERIES

ML-4550 ML-4551N ML-4551ND

Processor Marvell 500Mhz
Memory Std. 128 MB

Max. 512MB(256+256)

Printer Languages

Fonts - 45 scalable, 1 bitmap, 136 PostScript 3 fonts, OCR Fonts

Driver Default Driver PCL6 : Win 95/98/NT4.0/2000/Me/XP(32/64bits)/2003 Server(32/64bits)

Wired Network

Wireless Protocol N/A
Network
Application RCP N/A

Interface

Parallel - IEEE 1284
USB - High Speed USB 2.0

Wired Network
Wireless Network

User Interface
LCD - 16 x 12 Character LCD

LED - 2LED(Status LED, Save Button LED)

Key - 8 Key: Menu ,

- PostScript3, PCL6, IBM ProPrinter, EPSON, PDF Direct(only HDD installed)

PS : Linux & Mac

Supporting OS

Windows 95/98/NT4.0/2000/Me/XP(32/62bits)/2003 Server(32/62bits)
Various Linux OS including Red Hat 8~9, Fedora Core 1~3, Mandrake 9.2~10.1

and SuSE 8.2~9.2

Mac OS 8.6~9.2/10.1~10.4
WHQL Windows 2000, XP, 2003 Server

Protocol N/A SPX/IPX, TCP/IP, SNMP, HTTP 1.1, AppleTalk
Supporting OS

N/A Windows 98/ME/NT4.0/2000/XP(32/64bits)/2003

Server(32/64bits)
Netware 4.x, 5.x, 6.x
Mac OS 8.6~9.2, 10.1~10.4
Various Linux OS including Red Hat 8.0~9.2, Fedora
Core 1~3, Mandrake 9.2~10.1
and SuSE 8.2~9.2

Supporting OS

N/A

Status Monitor N/A
Smart Panel YES (Include RCP and SM)

Network N/A
Management

- Optional 10/100 Base TX

- N/A

, OK (*) , , Back Toner Save , Demo , Stop

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Specifications

2.2.3. Paper Handling

ITEM ML-4550 SERIES

ML-4550 ML-4551N ML-4551ND

Standard - 500-sheet Cassette Tray, 100-sheet Multi Purpose Tray @75g/
Capacity

Max. Capacity - 2,100 sheets @75g/
Printing Max. Size 216 x 356 mm (8.5" x 14")

Min. Size 76 x 127 mm (3.0" x 5.0")(>105g)
Multi-purpose tray

Capacity - 100 sheets @75g/
Media sizes - A4, A5, A6, Letter, Legal, Oficio, Folio, Executive,ISO B5, JIS B5, 3"x5", Monarch,

No.10, DL, C5, C6
Media type - Transparencies, Envelopes, Labels, Card stock

Media weight - 16~43 lb (60 to176g/
Sensing - Paper empty sensor
Standard Cassette Tray

Capacity - 500 sheets @ 75g/
Media sizes - A4, A5, Letter, Legal, Executive, Folio, Oficio, ISO B5, JIS B5

Media types - Plain Paper

Media weight - 16~28lb (60 to 105g/
Sensing - Paper empty sensor, Paper Size Sensor

Second Optional
Cassette Tray

Capacity - 500 sheets @ 75g/
Media sizes - A4, A5, Letter, Legal, Executive, Folio, Oficio, ISO B5, JIS B5
Media types - Plain Paper

Media weight - 16~28lb (60 to 105g/
Sensing - Paper empty sensor, Paper Size Sensor
Third Optional

Cassette Tray

Capacity - 500 sheets @ 75g/
Media sizes - A4, A5, Letter, Legal, Executive, Folio, Oficio, ISO B5, JIS B5
Media types - Plain Paper

Media weight - 16~28lb (60 to 105g/
Sensing - Paper empty sensor, Paper Size Sensor
Output Stacking

Capacity Face-Down 250 sheets @ 75g/

Face-Up 100 sheets @ 75g/

Output Full sensing

- Paper full Sensor

Optional Stacker
Capacity Face-Down N/A

Duplex - Optional Built-in
Supporting

Media sizes - A4, Letter, Legal, Folio, Oficio
Media types - Plain Paper

Media weight - 20~24lb (75~90g/

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Specifications

2.2.4. Consumables

ITEM ML-4550 SERIES

ML-4550 ML-4551N ML-4551ND

Toner Black Standard 10K pages @ ISO 19752 standard Coverage

High Yield 20K pages @ ISO 19752 standard Coverage
Key Electronic key(CRUM)
Life detect Toner remaining volume would be traced via software

Drum Yield Same as consumables

2.2.5. Reliability & Service

ITEM ML-4550 SERIES

ML-4550 ML-4551N ML-4551ND

Printing Volume
(SET AMPV)

Max. Monthly - 150,000 sheets
Duty

MPBF - 150,000 sheets
MTTR - 20 min.

SET Life Cycle - 500,000 sheets or 5 years (whichever comes first)

- 5,000 sheets / month

2.2.6. Environment

ITEM ML-4550 SERIES

ML-4550 ML-4551N ML-4551ND

Acoustic Noise
Level(Sound
Power/Pressure)

Power AVG. Less than 650W
Consumption

Dimension SET 396 x 453 x 353 mm (15.6" x 17.8" x 13.9") 396 x 501 x 353 mm
(W x D x H) (15.6" x 19.7" x 13.9")

Weight SET 17.8kg(39.2 Ib) 19.1kg

Printing Less than 57.0 dBA

Standby Less than 35.0 dBA
Sleep Back Ground Level

Sleep/Power Off

SET Packing 518 x 566 x 568 mm (External)

CRU 314 x 242 x 138 mm
Toner Packing

Toner(10K) 10K : 1.85kg(4.08 Ibs), 20K : 2.06kg(4.54 Ibs)

Gross 21.6kg(47.62 Ibs) 23.5kg(51.81 Ibs)

Less than 13W

370 x 286 x 180 mm (External)

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2.2.7. Options

ITEM ML-4550 SERIES

ML-4550 ML-4551N ML-4551ND

Memory - 128MB/512MB (256MB+256MB)
Second Cassette
Third Cassette - 500 sheet Cassette Tray

Stacker - N/A
Stapler N/A

PostScript - Default
Wired Network

Hard Disk - 40GB

Duplex Unit - Optional Default

- 500 sheet Cassette Tray

- Ethernet 10/100 Base Default Default

TX (Internal)

Specifications

2.2.8. Others

ITEM ML-4550 SERIES

ML-4550 ML-4551N ML-4551ND

Performance Jam Rate Base Line Paper : 1/12K
Requirement

Standard Paper : 1/10K
Stress Paper : 1/1500

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Specifications

Specifications

2.3 Model Comparison Table

Project SEC HP Lexmark Brother Dell

Model Name ML-4550 LJ-4250 T642 HL-8050N W5200N

Engine

FPOT 8.5 sec 8 sec 8.5 sec 9 sec 8.5 sec

Speed(ppm) 43ppm (Ltr. 45ppm) 43ppm (Ltr. 45ppm) 43ppm (Ltr. 45ppm) 34ppm (Ltr. 35ppm) 43ppm (Ltr. 45ppm)

Resolution 1200 dpi 1200 dpi 1200 dpi x 1200 dpi 1200dpi x 1200 dpi 1200 dpi x 1200 dpi

Noise(dB)

Weight 17.83kg 20.2kg (45 lbs) 23.1Kg (51lbs) 20.6Kg (45.2 lbs) 45lbs

Demension(W*D*H) 15.6

Control

Processor 500MHz 460MHz 457 MHz RISC 300MHz 500 MHz RISC

Ram(Std.) 128MB 48MB 64MB 64MB 80MB

Ram(Max.) 512MB 512MB 576MB 576MB 336MB

Emulation PCL6, PS3 PCL6, PS3 PCL6, PS3 PCL6, PS3, PCL6, PS3,

Interface IEEE1284, USB 2.0 IEEE1284, USB 2.0 IEEE1284, USB 1.1 IEEE1284, USB IEEE1284, USB

Optional Interface 10/100 Base TX 10/100 Base TX 10/100 Base TX N/A N/A

Paper Handling

Paper Input(Capa./Type)

Paper Output 250 Sheets Face down 250 Sheets Face down 500 Sheets Face Down 500 Sheet Face down 250 Sheets Face Down

Others

Max.Monthly Duty 150,000 sheets 200,000 sheets 225,000 sheets - 225,000 sheets

Consumable Yeild Standard 10K Standard 10K Standard 6K 17K Standard 18K

Power Consumption

Duplex Option Option Option Option NO

Options

57dB(Printing), 35dB(Idle)

x 17.8 x 13.9 16.5 x17.8 x14.8 436x523x406mm 16.6 x 18.3 x 15.9 (17.2 x20.2 x16 )

396 x 453 x 353 mm 418x451x377mm (17.2

500 Sheets 500 Sheets 500 Sheets 550 Sheets Cassette 500 Sheets
Cassette100 MP Tray Cassette100 MP Tray Cassette100 MP Tray 150 Sheets Cassette Cassette100 MP Tray

100 Sheets Face up 70 Sheet Face up

High Yield 20K High Yield 20K High Yield 21K High Yield 27K

Printing : Less than 650 W
Sleep : under 13 W Sleep : under 20 W Sleep:< 12W

- Memory (128MB/256MB)

- 3x500 sheet SCF - 500 sheet SCF - 3x250 sh drawer - Memory - 85 envelope

- Duplex - Duplex

- 40GB HD - HP Jetdirect

not_inform

Printing : 680 W not_inform Printing: < 593W not_inform

- Memory - 250 sh duplexer - SCF - duplexer

- 20GB HD

- Stacker & Stapler

55dB(Printing), 30dB(Idle) 54dB(Printing), 27dB(Idle) 55dB(Printing),

x20.6 x16 )

10/100 Base TX 10/100 Base TX

2.010/100 Base TX 2.010/100 Base TX

- 2000 sh drawer(Max.3850)

- 85 sh envelope feeder

- 650 sh output expander

- 1850 sh High capacity
output stacker

- 40 sheet staple

- 5 bin mailbox

(5x120 sh )

- Stand feeder

- Sorter/Mail box - 500 sheet cassette

- 250 sheet cassette

34dB(Idle)

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Samsung Electronics

ACCE

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Specifications

It

INA-ACCESSORY

CBF-POWER CORD

BAG PE

S/W APPLICATION-CD

S/W APPLICATION-CD

MANUAL-(CARD)WARRANTY CARD

MANUAL-NETWORK GUIDE

LABEL(P)-BLANK 90*25

ode

JC99-01974E

3903-000042

6902-000288

JC46-00280A

JC46-00293A

JC68-00690A

JC68-01579A

JC68-01584A

Quantit

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3. Summary of Product

This chapter describes the functions and operating principal of the main component.

3

3

3.1 Printer Components

3.1.1 Front View

Summary of Product

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Summary of Product

3.1.2 Rear View

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3.1.3 Control Panel

The control panel on the top right side of your printer has the display and the nine buttons.

Summary of Product

3.1.3.1 Display

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Summary of Product

3.1.3.2 Overview of Control Panel Menus

The control panel menus are used to configure the printer for your environment.
The control panel provides access to the following menus.

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Summary of Product

1 2

3 4

3.1.3.3 Special Features

Your new printer is equipped with special features that improve the print quality,giving you a competitive edge.
You can:

Print with excellent quality and high speed

• You can print up to 1200 x 1200 dpi effective output. See the Software Section.

• Your printer prints A4-sized paper at up to 43 ppm a and letter-sized paper at up to 45
ppm. For duplex printing, your printer prints A4-sized paper at up to 29 ipm b and letter­sized paper at up to 30 ipm.

Handle paper flexibly

• The multi-purpose tray supports letterheads, envelopes, labels, transparencies, custom­sized materials, postcards, and heavy paper. The multi-purpose tray holds up to 100
sheets of plain paper.

• The 500-sheet standard tray 1 supports plain paper in various sizes.

• The 500-sheet optional tray support plain paper in various sizes. You can install up to 3
additional trays.

• Two output tray; select either the output tray (face-down) or the rear cover (face-up) for the
most convenient access.

• Straight-through paper path capability from the multi-purpose tray to the rear cover.

Create professional documents

• Print Watermarks. You can customize your documents with words, such as “Confidential.”
See the Software Section.

• Print Posters. The text and pictures of each page of your document are magnified and
printed across the sheet of paper and can then be taped together to form a poster. See
the Software Section.

a. pages per minute

b. images per minute

Save your time and money

• This printer allows you to use toner save mode to save toner.

• You can print on both sides of the paper to save paper (double-sided printing) if you use
the ML-4551ND or install the optional duplex unit in the ML-4550 and ML-4551N.

• You can print multiple pages on a single sheet of paper to save paper (N-Up printing). See
the Software Section.

• You can use preprinted forms and letterhead with plain paper. See the Software Section.

• This printer automatically conserves electricity by substantially reducing power consump­tion when not in use.

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Summary of Product

Expand the printer capacity

• Your printer has 128 MB of memory which can be expanded to 512 MB.

• A Network interface enables network printing. You can add an optional network interface
card to the ML-4550. The ML-4551N and ML-4551ND come with a built-in network
interface, 10/100 Base TX.

• You can add 500-sheet optional trays to your printer. These trays let you add paper to the
printer less often.

• A PostScript 3 Emulation* (PS) enables PS printing.

Use the optional hard disk

You can install an optional hard disk in your printer.

• The 40 GB hard disk can store the data from your computer in the print queue. This decreases the workload of the
computer.

• You can use various print features, such as storing a job in the hard disk, proofing a job, and printing private docu­ments.

• You can manage the print jobs in the print queue of the printer hard disk. For details.

Print in various environments

• You can print in Windows 98/Me/NT 4.0/2000/XP/2003.

• Your printer is compatible with Linux and Macintosh.

• Your printer comes with both Parallel and USB interfaces.

• You can also use a network interface. The ML-4551N and ML-4551ND come with a built-in network interface, 10/100
Base TX. However, you need to install the optional wired network interface card to the ML-4550.

Printer Features

The table below lists a general overview of features supported by your printer.

(I: Installed, O: Option)

Features ML-4550 ML-4551N ML-4551ND

IEEE 1284 Parallel I I I

USB 2.0 I I I
Network Interface O I I

(Ethernet 10/100 Base TX)

Hard Disk O O O
PostScript* Emulation I I I
Duplex Unit O O I

Optional Tray 2 O O O
Optional Tray 3 O O O

Optional Tray 4 O O O

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3.2 System Layout

❶ Cassette ❷ Duplex
❸ MPF ❹ Print Cartridge
❺ LSU ❻ Fuser
❼ SMPS & HVPS Board ❽ Duplex Solenoid

Summary of Product

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Summary of Product

3.2.1 Feeding

It is consists of a basic cassette, an MP tray for supplying different types of media : envelope, label spe­cial paper, duplex unit, and parts related to paper transferring.

1) Separation method

Separate it from the friction pad mounted to the center of the cassette and apply retard roller that
uses a spring clutch. A feed roller uses an electronic clutch to control driving power.

2) Basic cassette

It takes a center loading method and applies 'friction pad separating method.' It means that there is
a paper sensor, but a paper size is detected after detecting the first paper by software.
Both the side guide and the rear guide can be adjusted for for various types of papers from A5 to
legal size paper.
It has a paper existence sensing function (Capacity: 500 sheets of general paper), paper arranging
function, various size papers accepting function, SCF paper path function, and displaying function
of paper remaining amount.
In the front side, there is a paper level indicator.

3) Pick-up roller

It has functions such as a paper pickup function, driving control function, paper feeding function,
and removing electronic static function.

4) Retard roller

It takes an arrangement method which uses a stopper roller and a weight without electric actuator.
It has paper separating function, driving control function, and multi feeding prevention function.

6) Registration roller

It has a paper arranging function, paper transferring function, paper detecting function, jam remov­ing function, and so on.

7) MP tray

It has a paper arranging function, paper transferring function, jam removing function, and so on.
It uses rubbing pad method to feed 100 sheets of general papers and 10 envelops.
It is possible to extend to 300mm for accepting a legal size paper.

8) Duplex unit

It has paper transferring function, paper guide function, jam removing function, paper sensing func­tion, and main board supporting function.
It is designed for basic attachment, and the duplex feeding takes a side feeding method. Usable
papers are A4, letter, and legal size paper.
For removing a jam occurred in a front part, it is designed to open a cassette and a guide.
It is designed to open a rear cover to remove a jam in a rear part.
If a face up tray is open, the duplex option cannot be used.

9) SCF (Second Cassette Feeder)

It is the same method with the main cassette, and the capacity is 500 sheets.
It has a separate driving mechanism. It is designed for a common use with a main cassette.

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Summary of Product

3.2.2 Transfer

It consists of a PTL (Pre-transfer Lamp) and a transfer roller. A PTL sheds light on an OPC drum, lowers
an electric potential of an OPC drum's surface, and improves the efficiency of the transfer.
A transfer roller transfers toner on an OPC drum to the paper.
Life span: Print over 150,000 sheets (In 16~27

)

3.2.3 Driver Ass'y

By driving the motor, the system takes power. It consists of a main motor for feeding fuser and duplex
reverse turn, and a deve-motor for a toner cartridge.

- Main Motor : DC 24V, Rated RPM : 1604rpm

- Deve Motor : DC 24V, Rated RPM : 1424 rpm

3.2.4 Fuser

It is consisted of a heat lamp, heat roller, pressure roller, thermistor and thermostat. It sticks the toner on
a paper by heat and pressure to complete the printing job.

- E-coil Heator : 1,300 Watt

50W

1) Thermostat

When a heat lamp is overheated, a Thermostat cuts off the main power to prevent over-heating.

- Non-Cotact type Thermostat

3) Heat roller

The heat roller transfers the heat from the e-coil to apply a heat on the paper. The surface of a
heat roller is coated with Teflon, so toner does not stick to the surface.

4) Pressure roller

A pressure roller mounted under a heat roller is made of a silicon resin, and the surface also is
coated with Teflon. When a paper passes between a heat roller and a pressure roller, toner
adheres to the surface of a paper permanently.

5) Items for safety

Protecting device for overheating

- 1st protection device: Hardware cuts off when overheated

- 2nd protection device: Software cuts off when overheated

- 3rd protection device: Thermostat cuts off main power.

Safety device

- A fuser power is cut off when a front cover is opened

- Maintain a temperature of fuser cover's surface under 80(C for user, and attach a caution
label at where customer can see easily when customer open a rear cover.

3.2.5 LSU (Laser Scanner Unit)

It is the core part of the LBP which switches from the video data received to the controller to the electro­static latent image on the OPC drum by controlling laser beam, exposing OPC drum, and turning principle
of polygon mirror. The OPC drum is turned with the paper feeding speed. The /HSYNC signal is created
when the laser beam from LSU reaches the end of the polygon mirror, and the signal is sent to the con­troller. The controller detects the /HSYNC signal to adjust the vertical line of the image on paper. In other
words, after the /HSYNC signal is detected, the image data is sent to the LSU to adjust the left margin on
paper. The one side of the polygon mirror is one line for scanning.

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Summary of Product

Cleaning Roller

Cleaning Blade

-650V

200V

-1.30KV

V

PP = 1500V, f = 3.0KHz

1

2

3

4

5

6

7

8

+5.0kV

-50V

+

-

200V

+

-

3.2.6 Print Cartridge

By using the electronic photo process, it creates a visual image. In the print cartridge, the OPC unit and
the toner cartridge unit are in a body. The OPC unit has OPC drum and charging roller, and the toner
cartridge unit has toner, supply roller, developing roller, and blade (Doctor blade)

- Developing Method: Non-contacting method

- Toner : Non magnetic 1 component pulverized type toner

- The life span of toner : 10,000 or 20,000 pages (LSA Pattern/A4 standard)

- Toner remaining amount detecting sensor : Yes

- OPC Cleaning : Cleaning blade type

- Management of disusable toner : Collect the toner by using Cleaning Blade

- OPC Drum protecting Shutter : Yes

- Classifying device for toner cartridge : ID is classified by CRUM.

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<Toner Cartridge Layout>

Samsung Electronics

Summary of Product

3.3 Engine H/W Specifications

3.3.1 ML-4550 (PCL) Main Board

The Engine Board and the Controller Board are in one united board, and it is consisted of CPU part and print part in func­tional aspect. The CPU is functioned as the bus control, O/O handling, drivers, and PC interface. The main board sends
the Current Image by Video data to the LSU and manages the conduct of Electrophotography for printing. It is consisted
of the circuits of the motor (paper feed, pass) driving, clutch driving, pre-transfer lamp driving, current driving, and fan driving.
The signals from the paper feed jam sensor and paper empty sensor are directly inputted to the main board.

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Summary of Product

3.3.1.1 Asic (ORION 2)

Marvell Feroceon 2850 ARM Compatoble (I-Cache: 32KB, D-Cache-32KB)
64-bit RISC embedded processor core
Dual bus architecture for bus traffic distribution

- AMBA High performance Bus (AHB)

- System Bus with SDRAM

- 64-bit Mbus Crossbar extension Interface with Flash and Device port

SDRAMC

- 32 Bits Dual mode DDR-II, 200MHz

- 4 Banks (Up to 256MB per Bank)

Device Controller

- Boot Flash 1 Bank (Up to 128MB)

- Device/NOR Flash 3 Banks (Up to 128MB per Bank)

No Graphic Execution Unit and Image processor
No Codec (Encoding / Decoding)
Printer Video Controller Interface for LBP engines

- Hyper-C : Printer Video Controller with RET algorithm
(Line Memory & Lookup Table Memory : 512 x 8 , 4096 x 16)

Dual / Single Beam, LVDS Pad (VDO, HSYNC)

PCI Controller

- 32Bits, 66MHz (PCI) / 133MHz (PCI-X)

- PCI Local Bus Specification rev. 2.2 compliant

- PCI Express Specification beta 1.0a compliant

- Host /Agent Mode (Support 3+4 Express Devices in Host Mode)

Engine Controller (LPEC1)

- LSU Interface unit

- Step Motor: 2 Channels

- PWM: 8 Channels

- ADC: 6 Channels

USB 2.0 Interface with Embedded USB 2.0 PHY
Gigabit Ethernet Controller

- IEEE 802.3 compliant with 10/100/1000 Mbps full-duplex GbE port

- Support GMII,MII and RGMII interface with external PHY/SERDES device

Package : 496pins PBGA
Power : 1.2V(Core), 3.3V(IO) power operation
Speed : 600MHz core(ARM9 Compatible) operation, 200MHz bus operation

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Summary of Product

3.3.1.2 Memory

NOR Flash Memory : It stores System Program and downloads the System Program through PC Interface, and in

case of model for export it compresses the PCL font, then stores it.

- Capacity : 128M Byte

- Access Time : 70 nsec

DDR SDRAM : It is used as Swath Buffer, System Working Memory Area, etc. when printing.
It stores Font List, compressed into Flash memory, on DRAM and uses it as PCL font in case of model for export.

- Capacity : 128 Byte(Basic), up to 512Mbyte (User Option)

- Type : DDR-II SDRAM 200MHz , 32bit

3.3.1.3 Others

The Option PBA can be mounted for supporting the serial communication.

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