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

SERVICE Manual

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

1.1Safety Warning 1-1

1.2Caution for safety 1-2

1.2.1Toxic material 1-2

1.2.2Electric Shock and Fire Safety Precautions 1-2

1.2.3Handling Precautions 1-3

1.2.4Assembly / Disassembly Precautions 1-3

1.2.5Disregarding this warning may cause bodily injury 1-4

1.3ESD Precautions 1-5

2.Product Specifications

2.1Product Overview 2-1

2.2Specifications 2-1

2.2.1General Specifications 2-1

2.2.2 Controller & S/W

2-2

2.2.3Paper Handling 2-3

2.2.4Consumables2-4

2.2.5Reliability & Service 2-4

2.2.6Environment 2-4

2.2.7Options 2-5

2.2.8Others2-5

2.3Model Comparison Table 2-6

3.Summary of Product

3.1Printer Components 3-1

3.1.1Front View 3-1

3.1.2Rear View 3-2

3.1.3Control Panel 3-3

3.2System Layout 3-7

3.2.1Feeding 3-8

3.2.2Transfer 3-9

3.2.3 Driver Ass'y

3-9

3.2.4Fuser 3-9

3.2.5LSU (Laser Scanner Unit)3-9

Continue...

3.2.6 Print Cartridge	3-10
3.3 Engine H/W Specifications	3-11
3.3.1 ML-4550 (PCL) Main Board	3-11
3.3.2 SMPS & HVPS board	3-16

3.3.3Engine F/W 3-20

4.Alignment and Adjustments

4.1 How to use EDC (Engine Diagnostic Control) Mode	4-1
4.1.1 EDC Setup	4-1
4.1.2 Entrance method for EDC	4-1

4.1.3Cover Status 4-2

4.1.4Sensor Status 4-3

4.1.5Motor Test 4-5

4.1.6Fan Test 4-5

4.1.7Clutch / Sol4-6

4.1.8Fuser Ctrl 4-7

4.1.9LSU 4-7

4.1.10Deve Control 4-8

4.1.11Print Test and Option version 4-9

4.2Paper Path 4-10

4.2.1Clearing Paper Jams 4-12

4.3Sample Pattern 4-17

4.3.1Information Pages 4-17

4.3.2Demo Pages 4-17

4.4Periodic Defective Image 4-18

4.5Error Messages 4-19

5.Disassembly and Reassembly

5.1General Precautions on Disassembly5-1

5.2Transfer Roller 5-2

5.3MPF Ass’y 5-3

5.4 Holder Pad Ass'y

5-4

5.5Retard Ass'y 5-5

5.6Feed2 Idle Unit 5-6

5.7Cover Right 5-7

Continue...

5.8	Main PBA	5-8
5.9	Main Drive Ass'y	5-9

5.10DEVE Drive Ass'y 5-10

5.11Connector PBA 5-11

5.12Solenoid 5-12

5.13Rear Cover 5-13

5.14Cover Left 5-14

5.15Top Cover 5-15

5.16Open Cover 5-16

5.17Inner Cover 5-17

5.18Fuser Ass'y 5-18

5.19Duplex Solenoid Ass'y 5-20

5.20Exit Roller 5-21

5.21LSU 5-22

5.22DC Fan 5-23

5.23Toner Sensor PBA 5-24

5.24REGI Ass'y 5-25

5.25MP Pick Up Ass'y 5-26

5.26Pick Up & Feed2 Assy 5-28

5.27Engine Shield 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	6-8
6.3	The cause and solution of the malfunction	6-13
6.4	Maintaining the toner cartridge	6-17
6.5	The cause and solutions of bad environment of the software	6-22

7.Exploded Views & Parts List

7.1Main Assembly 7-2

7.2Cover Assembly 7-5

7.3Frame Assembly 7-7

7.4Fuser Unit 7-12

7.5REGI Assembly 7-14

Continue...

7.6	Main Motor Assembly	7-16
7.7	Deve Motor Assembly	7-18
7.8	Exit Sorenoid Assembly	7-20
7.9	Cassette Assembly	7-22

7.10Duplex Unit 7-24

7.11SCF Unit 7-26

8.Block diagram

8.1System Block Diagram 8-1

9.Connection Diagram

9.1Connection Diagram 9-1

10.Schematic Diagram

10.1Main Board 10-1

10.2DIMM board 10-17

10.3CRUM board 10-19

10.4EMPTY board10-20

10.5HVPS 10-21

10.6Panel 10-25

10.7SCF 10-26

10.8Toner sensor 10-29

10.9HDD.eps10-30

11.Reference Information

11.1Troubleshooting Tools 11-1

11.2 Acronyms and Abbreviations

11-2

11.3Select a location for the printer 11-4

11.4Sample Tests Patterns 11-5

1	Precautions

1. Precautions

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 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.

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.

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 LASER-

S TEILYLLE L KATSO S TEESEEN.

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Samsung Electronics

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 completely 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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Samsung Electronics

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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Samsung Electronics

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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Samsung Electronics

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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Samsung Electronics

			Specifications
	2. Product Specifications
22.1 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)

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	Less than 53.5 sec
Resolution	-	Up to 1200 x 1200 dpi effective output

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Samsung Electronics

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	-	PostScript3, PCL6, IBM ProPrinter, EPSON, PDF Direct(only HDD installed)
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)
		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
Wired Network	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
Wireless	Protocol	N/A
Network	Supporting OS	N/A
Application	RCP	N/A
	Status Monitor	N/A
	Smart Panel	YES (Include RCP and SM)
	Network	N/A
	Management
Interface
Parallel	-	IEEE 1284
USB	-	High Speed USB 2.0
Wired Network	-	Optional		10/100 Base TX
Wireless Network	-	N/A
User Interface
LCD	-	16 x 12 Character LCD
LED	-	2LED(Status LED, Save Button LED)
Key	-	8 Key: Menu , , OK (*) ,		, Back Toner Save , Demo , Stop

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Samsung Electronics

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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Samsung Electronics

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	-	5,000 sheets / month
(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)

2.2.6. Environment

ITEM			ML-4550 SERIES
		ML-4550		ML-4551N	ML-4551ND
Acoustic Noise	Printing	Less than 57.0 dBA
Level(Sound
Power/Pressure)
	Standby	Less than 35.0 dBA
	Sleep	Back Ground Level
Power	AVG.	Less than 650W
Consumption	Sleep/Power Off	Less than 13W
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")
	SET Packing	518 x 566 x 568 mm (External)
	CRU	314 x 242 x 138 mm
	Toner Packing	370 x 286 x 180 mm (External)
Weight	SET	17.8kg(39.2 Ib)			19.1kg
	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)

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Specifications

2.2.7. Options

ITEM			ML-4550 SERIES
		ML-4550	ML-4551N	ML-4551ND
Memory	-	128MB/512MB (256MB+256MB)
Second Cassette	-	500 sheet Cassette Tray
Third Cassette	-	500 sheet Cassette Tray
Stacker	-	N/A
Stapler		N/A
PostScript	-	Default
Wired Network	-	Ethernet 10/100 Base	Default	Default
		TX (Internal)
Hard Disk	-	40GB
Duplex Unit	-	Optional		Default

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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Samsung Electronics

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)	57dB(Printing), 35dB(Idle)	not_inform	55dB(Printing), 30dB(Idle)	54dB(Printing), 27dB(Idle)	55dB(Printing), 34dB(Idle)
Weight	17.83kg	20.2kg (45 lbs)	23.1Kg (51lbs)	20.6Kg (45.2 lbs)	45lbs
Demension(W*D*H)	15.6 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 x20.6 x16 )
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,
				10/100 Base TX	10/100 Base TX
Interface	IEEE1284, USB 2.0	IEEE1284, USB 2.0	IEEE1284, USB 1.1	IEEE1284, USB	IEEE1284, USB
				2.010/100 Base TX	2.010/100 Base TX
Optional Interface	10/100 Base TX	10/100 Base TX	10/100 Base TX	N/A	N/A
Paper Handling
Paper Input(Capa./Type)	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
Paper Output	250 Sheets Face down	250 Sheets Face down	500 Sheets Face Down	500 Sheet Face down	250 Sheets Face Down
	100 Sheets Face up			70 Sheet Face up
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
	High Yield 20K	High Yield 20K	High Yield 21K		High Yield 27K
Power Consumption	Printing : Less than 650 W	Printing : 680 W	not_inform	Printing: < 593W	not_inform
	Sleep : under 13 W	Sleep : under 20 W		Sleep:< 12W
Duplex	Option	Option	Option	Option	NO
Options	- Memory (128MB/256MB)	- Memory	- 250 sh duplexer	- SCF	- duplexer
	- 3x500 sheet SCF	- 500 sheet SCF	- 3x250 sh drawer	- Memory	- 85 envelope
	- Duplex	- Duplex	- 2000 sh drawer(Max.3850)	- Stand	feeder
	- 40GB HD	- HP Jetdirect	- 85 sh envelope feeder	- Sorter/Mail box	- 500 sheet cassette
		- 20GB HD	- 650 sh output expander		- 250 sheet cassette
		- Stacker & Stapler	- 1850 sh High capacity
			output stacker
			- 40 sheet staple
			- 5 bin mailbox
			(5x120 sh )

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				Specifications
	ACCESSORY
	Item	Code		Quantity
	INA-ACCESSORY	JC99-01974E
	CBF-POWER CORD	3903-000042
	BAG PE	6902-000288
	S/W APPLICATION-CD	JC46-00280A
	S/W APPLICATION-CD	JC46-00293A
	MANUAL-(CARD)WARRANTY CARD	JC68-00690A
	MANUAL-NETWORK GUIDE	JC68-01579A
	LABEL(P)-BLANK 90*25	JC68-01584A

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Summary of Product

33. Summary of Product

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

3.1 Printer Components

3.1.1 Front View

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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.

3.1.3.1 Display

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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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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

1 2

3 4

•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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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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Summary of Product

3.2 System Layout

		Cassette		Duplex
		MPF		Print Cartridge
		LSU		Fuser
		SMPS & HVPS Board		Duplex Solenoid

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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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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

3.2.4Fuser

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.

3.2.5LSU (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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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.

	2	Cleaning Roller
			VPP = 1500V, f = 3.0KHz
			4
			-		200V
	-1.30KV				+
			-650V	+	-
			-50V	200V
	1
	8 Cleaning Blade		3
			6
					5
			+5.0kV
			7

<Toner Cartridge Layout>

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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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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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