Samsung ML-3750ND Service Manual

Mono Laser Printer

ML-3750ND

SERVICEMANUAL

Mono Laser Printer

Contents

1. Precautions

2. Product Specifications

3. Disassembly and Reassembly

4. Alignment and Troubleshooting

5. System Diagram

6. Reference Information

Refer to the service manual in the GSPN (see the rear cover) for more information.

Contents

Contents

1.	Precautions ......................................................................................................................................				1	−	1
	1.1.	Safety warning ........................................................................................................................			1	−	1
	1.2.	Caution for safety ....................................................................................................................			1	−	2
		1.2.1.	Toxic material.............................................................................................................		1	−	2
		1.2.2. Electric shock and fire safety precautions .........................................................................			1	−	2
		1.2.3.	Handling precautions ...................................................................................................		1	−	3
		1.2.4. Assembly and Disassembly precautions...........................................................................			1	−	3
		1.2.5. Disregarding this warning may cause bodily injury ............................................................			1	−	4
	1.3.	ESD precautions......................................................................................................................			1	−	5
2.	Product Specifications........................................................................................................................				2	−	1
	2.1.	Specifications..........................................................................................................................			2	−	1
		2.1.1.	Product Overview........................................................................................................		2	−	1
		2.1.2.	Specifications .............................................................................................................		2	−	1
			2.1.2.1.	General Print Engine......................................................................................	2	−	1
			2.1.2.2.	Controller and Software..................................................................................	2	−	2
			2.1.2.3.	Paper Handling.............................................................................................	2	−	4
			2.1.2.4.	Consumables................................................................................................	2	−	5
			2.1.2.5.	Reliability and Service ...................................................................................	2	−	5
			2.1.2.6.	Maintenance part...........................................................................................	2	−	5
			2.1.2.7.	Environment ................................................................................................	2	−	5
		2.1.3.	Model Comparison Table ..............................................................................................		2	−	7
	2.2.	Product Description..................................................................................................................			2	−	8
		2.2.1.	Front View.................................................................................................................		2	−	8
		2.2.2.	Rear View	..................................................................................................................	2	−	9
		2.2.3.	Paper Path..................................................................................................................		2	− 10
		2.2.4.	System layout .............................................................................................................		2	− 11
			2.2.4.1.	Feeding Part.................................................................................................	2	− 12
			2.2.4.2.	Toner cartridge .............................................................................................	2	− 14
			2.2.4.3.	Fuser unit ....................................................................................................	2	− 16
			2.2.4.4. LSU (Laser Scanning Unit) .............................................................................		2	− 17
		2.2.5.	Hardware Configuration................................................................................................		2	− 18
			2.2.5.1.	Main board ..................................................................................................	2	− 19
			2.2.5.2.	OPE board ...................................................................................................	2	− 21
			2.2.5.3.	DIMM PBA - Optional...................................................................................	2	− 22
			2.2.5.4.	SCF board - Optional .....................................................................................	2	− 22
			2.2.5.5.	SMPS board.................................................................................................	2	− 23
			2.2.5.6.	HVPS board.................................................................................................	2	− 24
		2.2.6. Engine F/W Control Algorithm ......................................................................................			2	− 25

i	Copyright© 1995-2011 SAMSUNG. All rights reserved.

Contents

		2.2.6.1.	Feeding .......................................................................................................	2	− 25
		2.2.6.2.	Transfer.......................................................................................................	2	− 25
		2.2.6.3.	Fusing.........................................................................................................	2	− 26
		2.2.6.4.	LSU............................................................................................................	2	− 26
	2.2.7.	Software Descriptions ..................................................................................................		2	− 27
		2.2.7.1.	Software system overview ..............................................................................	2	− 27
		2.2.7.2.	Architecture .................................................................................................	2	− 27
		2.2.7.3. Data and Control Flow ...................................................................................		2	− 28
3.	Disassembly and Reassembly ..............................................................................................................			3	−	1
	3.1. Precautions when replacing parts ................................................................................................			3	−	1
	3.1.1.	Precautions when assembling and disassembling ...............................................................		3	−	1
	3.1.2.	Preautions when handling PBA ......................................................................................		3	−	1
	3.1.3.	Releasing Plastic Latches..............................................................................................		3	−	2
	3.2. Screws used in the printer..........................................................................................................			3	−	3
	3.3. Replacing the Main SVC parts ...................................................................................................			3	−	4
	3.3.1.	Cover........................................................................................................................		3	−	4
	3.3.2.	Main board.................................................................................................................		3	−	6
	3.3.3.	HVPS board ...............................................................................................................		3	−	6
	3.3.4.	SMPS board ...............................................................................................................		3	−	7
	3.3.5.	Laser Scanning Unit (LSU) ...........................................................................................		3	−	7
	3.3.6.	Fuser unit...................................................................................................................		3	−	8
	3.3.7.	Main Drive unit...........................................................................................................		3	−	9
	3.3.8.	Feed drive unit............................................................................................................		3	− 10
	3.3.9.	Pick up/ Regi./ MP Clutch.............................................................................................		3	− 11
	3.3.10.	Pick up roller..............................................................................................................		3	− 11
	3.3.11.	Transfer Roller............................................................................................................		3	− 12
	3.3.12.	MP unit .....................................................................................................................		3	− 12
	3.3.13.	OPE board .................................................................................................................		3	− 13
	3.3.14.	Bin-full sensor ............................................................................................................		3	− 13
	3.3.15.	Regi_Feed_Empty sensor..............................................................................................		3	− 14
	3.3.16.	Cassette roller (Retard roller).........................................................................................		3	− 15
4.	Alignment and Troubleshooting ...........................................................................................................			4	−	1
	4.1. Alignment and Adjustments.......................................................................................................			4	−	1
	4.1.1.	Control Panel..............................................................................................................		4	−	1
	4.1.2.	Understanding The Status LED ......................................................................................		4	−	2
	4.1.3.	Clearing paper jams .....................................................................................................		4	−	3
	4.1.4.	Useful menu item for service .........................................................................................		4	−	7
	4.1.5.	Periodic Defective Image..............................................................................................		4	−	9
	4.1.6.	Useful management tools..............................................................................................		4	− 10
		4.1.6.1. Using Samsung Easy Printer Manager (Windows only) ........................................		4	− 10

Copyright© 1995-2011 SAMSUNG. All rights reserved.

ii

Contents

			4.1.6.2. Using Samsung Printer Status (Windows only) ...................................................	4	− 12
			4.1.6.3. Using Smart Panel (Macintosh and Linux only) ..................................................	4	− 13
			4.1.6.4. Using SyncThru Web Service (SWS) ................................................................	4	− 14
		4.1.7.	Updating Firmware ......................................................................................................	4	− 16
			4.1.7.1. Update the firmware by using the USB port ........................................................	4	− 16
			4.1.7.2. Update the firmware by using the network ..........................................................	4	− 17
		4.1.8.	Tech Mode .................................................................................................................	4	− 19
	4.2.	Troubleshooting ......................................................................................................................		4	− 22
		4.2.1. Procedure of checking the symptoms...............................................................................		4	− 22
			4.2.1.1. Basic Check List ...........................................................................................	4	− 23
		4.2.2. Error Code and Troubleshooting.....................................................................................		4	− 24
		4.2.3.	Image quality problem ..................................................................................................	4	− 36
		4.2.4.	Other errors ................................................................................................................	4	− 42
5.	System Diagram................................................................................................................................			5	−	1
	5.1.	Block Diagram........................................................................................................................		5	−	1
	5.2.	Connection Diagram.................................................................................................................		5	−	2
6.	Reference Information........................................................................................................................			6	−	1
	6.1.	Tool for Troubleshooting...........................................................................................................		6	−	1
	6.2.	Glossary	.................................................................................................................................	6	−	2
	6.3. The Sample ..................................................................................................Pattern for the Test			6	−	8
	6.4.	Selecting ..................................................................................................................a location		6	−	9

iii	Copyright© 1995-2011 SAMSUNG. All rights reserved.

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 a factory trained service technician.

High voltages and lasers inside this product are dangerous. This product should only be serviced by a factory trained service technician.

2)Use only Samsung replacement parts.

There are no user serviceable parts inside the product. Do not make any unauthorized changes or additions to the product as these could cause the product to malfunctions and create an electric shocks 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 I(1) laser products, and elsewhere is certified as a Class I laser product conforming to the requirements of IEC 60825-1. 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.

•Wavelength: 800 nm

•Beam divergence

-Paraller: 12 degrees

-Perpendicular: 35 degrees

•Maximum power of energy output: 15 mW

WARNING

Never operate or service the product 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 precautions should always be followed to reduce risk of fire, electric shock, and personal injury.

Copyright© 1995-2011 SAMSUNG. All rights reserved.

1-1

1. Precautions

1.2. Caution for safety

1.2.1. Toxic material

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

1)Please keep imaging unit and toner cartridge away from children. The toner powder contained in the imaging unit and 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 product and potentially cause a fire or electric shock.

2)Use only the power cable supplied with the product. 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 product, this can cause electric shock. Do not allow paper clips, pins or other foreign objects to fall into the product, 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 product, remove the power plug from the wall socket.

6)Use caution when inserting or removing the power cord. When removing the power cord, grip it firmly and pull. The power cord must be inserted completely, otherwise a poor contact could cause overheating leading to a fire.

7)Take care of the power cable. Do not allow it to become twisted, bent sharply around corners or power cable may be damaged. Do not place objects on top of the power cable. If the power cable is damaged it could overheat and cause a fire. Exposed cables could cause an electric shock. Replace the 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 lightning 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 product in a clean well ventilated location. Do not position the machine near a humidifier or in front of an air conditioner. Moisture and dust built up inside the machine can lead to overheating and cause a fire or cause parts to rust.

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

13)When replacing the SMPS board, please wait 5 minutes after unplugging the power cord, then replace it. You can get a shock by the electric discharge.

1-2	Copyright© 1995-2011 SAMSUNG. All rights reserved.

1. 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 product.

1)Ensure the product is installed on a level surface, capable of supporting its weight. Failure to do so could cause the product to tip or fall.

2)The product 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 product 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 product in such areas.

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

1.2.4. Assembly and Disassembly precautions

1)Replace parts carefully and 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 product or replacing any parts.

2)Ensure that power is disconnected before servicing or replacing any electrical parts.

3)Disconnect 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 minutes can damage the surface of the photoconductive properties and will result in print quality degradation. Take extra care when servicing the product. 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.

Copyright© 1995-2011 SAMSUNG. All rights reserved.

1-3

1. 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 unit to cool down before disassembly.

2)Do not put fingers 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, use safe lifting and handling techniques.

This printer is heavy. 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.

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.

1-4	Copyright© 1995-2011 SAMSUNG. All rights reserved.

1. 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.

Copyright© 1995-2011 SAMSUNG. All rights reserved.

1-5

2. Product Specifications

2. Product Specifications

2.1. Specifications

2.1.1. Product Overview

1)Speed

•35 ppm in A4 / 37 ppm in Letter

2)Processor

•533 MHz

3)Printer Languages

•PCL6/5e, PostsScript3, IBM ProPrinter, EPSON

4)Memory (Std / Max)

•128 MB / 512MB

5)Interfaces

•High Speed USB 2.0

•10/100/1000 BaseTX network connector

•IEEE 1284 Parallel (Optional)

6)Toner cartridge (Initial / Sales)

•7K / 7K, 15K

2.1.2. Specifications

•Product Specifications are subject to change without notice.

2.1.2.1. General Print Engine

Item		Specification
Engine Speed	Simplex	Up to 35 ppm in A4 (37 ppm in Letter)
	Duplex	Up to 17 ipm in A4 (18 ipm in Letter)
Warm-up time	From Sleep	15 sec
FPOT	From Ready	As fast as 8 sec
	From Sleep	As fast as 15.5 sec
Resolution		Up to 1,200 x 1,200 dpi effective output

2-1	Copyright© 1995-2011 SAMSUNG. All rights reserved.

2. Product Specifications

2.1.2.2. Controller and Software

Item		Specification
Processor		Samsung 533 MHz
Memory	Std	128 MB
	Max	512 MB
	Flash	16 MB
Printer Languages		PostScript3, PCL6/5e, IBM ProPrinter, EPSON
Fonts		93 scalable, 1 bitmap, 136 PostScript3 fonts
Driver	Default Driver	PCL
	Install	PCL6 / PS3
	Supporting OS	Windows 2000/ XP(32/64bits)/ Vista(32/64bits)/ 2003
		Server(32/64bits)/ 2008 Server(32/64bits)/ 7(32/64bits)/ 2008 Server
		R2(64bits)
		Various Linux OS :
		• RedHat Enterprise Linux WS 4, 5 (32/64 bit)
		• Fedora 4, 5, 6, 7, 8, 9, 10, 11, 12 (32/64 bit)
		• SuSE Linux 10.0, 10.1 (32 bit)
		• OpenSuSE 10.2, 10.3, 11.0, 11.1, 11.2 (32/64 bit)
		• Mandriva 2005, 2006, 2007, 2008, 2009, 2009.1 (32/64 bit)
		• Ubuntu 5.04, 5.10, 6.06, 6.10, 7.04, 7.10, 8.04, 8.10, 9.04,
		9.10(32/64 bit)
		• SuSE Linux Enterprise Desktop 10, 11 (32/64 bit)
		• Debian 4.0, 5.0 (32/64 bit)
		Mac OS 10.3 ~ 10.6
		UNIX OS :
		• Sun Solaris 9,10 (x86, SPARC)
		• HP-UX 11.0, 11i v1, 11i v2, 11i v3 (PA-RISC, Itanium)
		• IBM AIX 5.1, 5.2, 5.3, 5.4
	WHQL	Windows 2000/ XP(32/64bits)/ Vista(32/64bits)/ 2003
		Server(32/64bits)/ 2008 Server(32/64bits)/ 7(32/64bits)/ 2008 Server
		R2(64bits)
	Compatibility	• PCL6 : Win 2000/ XP(32/64bits)/ 2003 Server(32/64bits)/
		Vista(32/64bits)/ 2008 Server(32/64bits)/ 7(32/64bits)/ 2008
		Server R2(64bits)
		• PS3 : Win 2000/ XP(32/64bits)/ Vista(32/64bits)/ 2003
		server(32/64bits)/ 2008 Server(32/64bits)/ 7 (32/64bits)/2008
		Server R2(64bits) PPD, Mac PPD, Linux PPD (Within the
		scope of Supporting OS)

Copyright© 1995-2011 SAMSUNG. All rights reserved.

2-2

2. Product Specifications

Item		Specification
Wired Network	Protocol	•	[TCP/IP]
			TCP/IPv4/IPv6, HTTP, SNMPv1/v2c/v3, SMTP, IPSec,
			DNS/WINS, DDNS, DHCP, SSL/TLS, BOOTP, AutoIP,
			Standard TCP/IP printing, LPR, IPP, UPnP(SSDP), Bonjour,
			Telnet, WSD, SLP, SetIP
		•	[Others]
			HTTPs,IPPs, 802.1x(EAP-MD5,EAP-MSCHAPv2,
			PEAP,TLS), IPSec
	Supporting OS	•	[Windows]
			• Microsoft Windows 2000/ XP(32/64bits)/
				2003(32/64bits)/ Vista(32/64bits)/ 2008(32/64bit)/
				7(32/64bit)
		•	[Mac]
			•	Mac OS 10.3~10.6
		•	[Linux]
			• RedHat 8 ~ 9(32bit)/ Enterprise Linux WS 4, 5 (32/64bit)
			• Fedora Core 1 ~ 7 (32/64bit)
			• SuSE 8.2 ~ 10.2/Enterprise Desktop 9~10 (32/64bit)
			• Madrake 9.2 ~ 10.1 (32/64bit)
			• Mandriva 2005 ~ 2007
			• Ubuntu 6.06 ~ 7.04
			• Debian 3.1 ~ 4.0[Novell] - Netware 5.x, 6.x(TCP/IP Only)
		•	[Novell]
			• Netware 5.x, 6.x(TCP/IP Only)
		•	[Unix]
			•	Sun Solaris 8,9,10(SPARC/x86)
			• IBM AIX 5.x (6.1) IBM Linux (System P)
			•	HP-UX 11i (PA-RISC/IA-64)
				(11.11/11.20/11.22/11.23/11.31)
Wireless Network	Protocol	N/A
	Supporting OS	N/A
Application	Easy Printer Manager	for Windows/ Macintosh/LINUX
	Network Management	SyncThru Web Admin Service 5.0
Interface	Parallel	Option
	USB	Hi-Speed USB 2.0
	Wired Network	Gigabit (Internal)
	Wireless Network	N/A
User Interface	LCD	2-Line
	LED	Navigation, ECO, Power, Status
	Key	Navigation keys, ECO, Numeric Keypad, Power, Cancel

2-3	Copyright© 1995-2011 SAMSUNG. All rights reserved.

				2. Product Specifications
	2.1.2.3. Paper Handling
	Item		Specification
	Standard Capacity		250-sheet Cassette Tray, 50-sheet Multi Purpose Tray @80g/m²
	Max. Capacity		820 sheets @ 80g/m² (850 sheets @ 75g/m²)
	Printing		•	Max. Size : 216 x 356 mm (8.5" x 14")
			•	Min. Size : 76 x 127 mm (3.0" x 5.0")
		Capacity	• Plain Paper : 50 sheets @ 80g/m² (50 sheets @ 75g/m²)
			•	Envelop : 5 sheets
		Media sizes	A4, A5, A6, Letter, Legal, Folio, Oficio, Executive, ISO B5, JIS B5,
			3"x5", Envelope (Monarch, No.10, DL, C5, C6), Custom
	Multi-purpose tray
		Media type	Plain, Thin, Thick, Thicker, Cotton, Colored, Envelope, Transparency,
			Pre-Printed, Recycled, Labels, Bond, Card stock, Archive
		Media weight	16~58 lb (60 to 220 g/m²)
		Sensing	Paper Empty
		Capacity	250 sheets @ 80 g/m² (250 sheets @ 75 g/m²)
		Media sizes	A4, A5, A6, Letter, Legal, Folio, Oficio, Executive, ISO B5, JIS B5,
			Custom
	Standard Cassette Tray
		Media types	Plain Paper, Thin, Thick, Recycled, Bond, Cardstock, Archive
		Media weight	16~43 lb (60 to 163 g/m²)
		Sensing	Paper Empty
		Capacity	520 sheets @ 80 g/m² (550 sheets @ 75 g/m²)
		Media sizes	A4, A5, A6, Letter, Legal, Folio, Oficio, Executive, ISO B5, JIS B5
	Optional Cassette Tray	Media types	Plain Paper, Thin, Thick, Recycled, Bond, Cardstock, Archive
		Media weight	16~43 lb (60 to 163 g/m²)
		Sensing	CST Open, Paper Empty
		Capacity	• Face-Down : 150 sheets @ 80 g/m²
	Output Stacking		•	Face-Up : 1 sheet
		Output Full sensing	Yes
		Supporting	Built-in
	Duplex	Media sizes	A4, Letter, Oficio, Folio, Legal
		Media types	Plain Paper, Thin, Thick, Recycled, Bond
		Media weight	16~32 lb (60 to 120 g/m²)
			• Envelop : 10 mm (0.4") from edge (Top, Bottom, Left, Right)
	Printable Area	Non-Printable Area	• Other Media : 4 mm (0.16") from edge (Top, Bottom, Left,
				Right)

Copyright© 1995-2011 SAMSUNG. All rights reserved.

2-4

2. Product Specifications

2.1.2.4. Consumables

Item		Specification
Toner	Black	• Standard: Average Cartridge Yield 7K standard pages.
		• High Yield: Average cartridge Yield 15K standard pages.
		(Ships with 7,000 pages Starter Toner Cartridge)
		Declared cartridge yield in accordance with ISO/IEC 19752.
	Key	Electronic key (CRUM) Only
	Life detect	Toner gauge sensor by dot count
Drum	Yield	N/A

2.1.2.5. Reliability and Service

Item	Specification
Recommanded AMPV	1500 sheets/month
Max AMPV	3500 sheets/month
Max. Monthly Duty	80,000 sheets/month
MPBF	45,000 sheets
MTBF	35 months
MTTR	30 min.

2.1.2.6. Maintenance part

Item	Part Code		Life
Transfer roller	JC66-02842A		Approx. 100,000 Pages
Fuser Unit	•	JC91-01023A (110V)	Approx. 90,000 Pages
	•	JC91-01024A (220V)
Pick-up Roller	JC73-00340A		Approx. 90,000 Pages
Reverse Roller	JC90-01032A		Approx. 60,000 Pages

2.1.2.7. Environment

Item		Specification
Operating Environment	Temperature	10C to 32C
	Humidity	20% to 80%
Acoustic Noise Level	Printing	52 dBA
(Sound Power/Pressure)
	Standby	Back Ground Level (Less than 26 dBA)
	Sleep	Back Ground Level

2-5	Copyright© 1995-2011 SAMSUNG. All rights reserved.

		2. Product Specifications
Item		Specification
Power Consumption	Ready	Less than 60W
	Average	Less than 550W
	Power save / Power Off	Less than 1.5W / Less than 0.1W
Dimension (W x D x H)	Set	366 x 368 x 272.9 mm (14.40 x 14.48 x 10.74 inches) without optional
		tray
Weight	Set (Include toner	10.24 kg (22.58 lbs)
	cartridge)

Copyright© 1995-2011 SAMSUNG. All rights reserved.

2-6

2. Product Specifications

2.1.3. Model Comparison Table

	Samsung		Samsung		HP		Lexmark
	ML-3750ND		ML-3710ND		P2050 series		E360dn
Image
Speed	35 ppm (A4) / 37 ppm		35 ppm (A4) / 37 ppm		33 ppm (A4)		38 ppm (A4)
	(Letter)		(Letter)
Processor	533 MHz		600 MHz		600 MHz		400 MHz
Memory	128/ 512 MB		128/ 384 MB		P2055dn (128/ 384 MB)		32 / 288 MB
(Std/Max)					P2055d (64/ 320 MB)
Emulation	PCL6/5e, PS3		PCL6/5e, PS3		PCL6		PCL6/PS3
MP/Cassette	50 / 250		50 / 250		50 / 250		50 / 250
SCF	520 sheets		520 sheets		500 sheets		550 sheets
Duplex	Std.		Std.		Std.		Std.
Toner Yield	7K/ 15K		2K/ 5K / 10K		2.3K/ 6.5K		3.5K / 9K
Interface	•	High speed USB	•	High speed USB	•	High speed USB	•	High speed USB
		2.0		2.0		2.0		2.0
	•	Ethernet	•	Ethernet	•	Ethernet	•	Ethernet 10/100
		10/100/1000 Base		10/100/1000 Base		10/100/1000 Base		Base TX
		TX		TX		TX (P2055dn)
Noise	52dB		52dB		55dB		53dB

2-7	Copyright© 1995-2011 SAMSUNG. All rights reserved.

2. Product Specifications

2.2. Product Description

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

2.2.1. Front View

1Output tray

2Control panel

3Control board cover

4Front cover

5Paper level indicator

6Optional tray

7Tray 1

8Multi-purpose tray

9Multi-purpose tray paper extension

10Paper width guides on a multi-purpose tray

11Output support

Copyright© 1995-2011 SAMSUNG. All rights reserved.

2-8

2. Product Specifications

2.2.2. Rear View

1	Network Port
2	USB port
3	USB port 2* (ML-3753ND only)
4	IEEE 1284 parallel connector power supply jack
5	Power-switch
6	Power receptacle
7	Duplex unit
8	Rear cover
9	Tray back cover

* Two USB ports allow you to connect a printer to two separate computers. Printer drivers need to be installed on both computers for this operation. Double connections from a printer to a single computer through the USB ports can result in serious damage to the printer and computer.

2-9	Copyright© 1995-2011 SAMSUNG. All rights reserved.

2. Product Specifications

2.2.3. Paper Path

The following diagram displays the path the paper follows during the printing process.

Copyright© 1995-2011 SAMSUNG. All rights reserved.		2-10

2. Product Specifications

2.2.4. System layout

This model consists of the Engine parts, Hardware and Firmware. The engine parts consists of the mechanical parts comprising Frame, Duplex, Toner cartridge, Drive unit, Transfer roller, Fuser, Cassette. The Hardware part consists of the main control board, power board, operation panel, PC Interface.

1LSU (Laser Scanning Unit)

2Toner Cartridge

3Regi. Roller

4MP

5Feed Roller

6Pick-Up Roller

7Cassette

8Duplex Unit

9Fuser

10Exit Roller1

11Exit Roller2

2-11	Copyright© 1995-2011 SAMSUNG. All rights reserved.

2. Product Specifications

2.2.4.1. Feeding Part

It consists of a cassette, an MP tray for supplying different types of media (envelope, label, special paper) and parts related to paper feed initialization.

1) Cassette

The paper trays consist of the Main trays, Optional trays (SCF), and one Multi-Purpose (MP) tray. The basic cassette is located on front side of the machine and allows feeding of common paper. Paper size is set using the Size Guides in each tray. Adjust the Paper length/width guides to match the paper size.

2) Pick up / Retard (Reverse) roller

When pickup takes place, the pickup roller rotates to separate and transport the paper. The pickup roller rotates when the pickup clutch is activated. The reverse roller serve to make sure that a single sheet of paper is moved to the paper path, and the paper is moved as far as the registration roller by the work of the feed roller. The following is a diagram of the pickup section :

3) Registration roller

It is used as an anti skew device, and to setup proper registration timing with that of the toned image on the drum. It also is used for jam detection to ensure paper has left the paper tray.

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2-12

2. Product Specifications

4) MP Tray

The multi-purpose tray can hold special sizes and types of print material, such as postcards, note cards, and envelopes. It is useful for single page printing on letterhead or colored paper. It uses 3 rollers feeding method to feed 50 sheets of general papers.

5) Duplex Unit

It has paper transferring function, paper guide function, jam removing 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.

6) Option Cassette

It is the same method with the main cassette, and the capacity is 520 sheets. It has a separate driving mechanism. It is designed for a common use with a main cassette.

2-13	Copyright© 1995-2011 SAMSUNG. All rights reserved.

2. Product Specifications

2.2.4.2. Toner cartridge

1) Printing process overview

This mono printing system includes the LSU with a laser beams, a toner cartridge and transfer roller.

This machine uses single toner cartridge and dual laser beams for mono printing. The toner cartridge consists of Drum unit and Development unit. The Drum unit has an OPC drum, cleaning blade.

The OPC drum is charged with a negative voltage by the scorotron and is exposed by the light from the LSU (Laser Scanning unit). The light produced by a laser creates a latent image by discharging on the surface of the OPC drum. The negatively charged toners are attracted to the latent image due to and electric field. The toners (real image) on the OPC drum are moved to the transfer media by the positive bias applied to the transfer roller.

1)Charging the OPC drum : The scorotron gives the drum negative charges.

2)Laser exposure : Light produced by a laser diode irradiates the charged OPC through the lens and mirrors.

3)Development : This machine uses a dual-component development system . The magnetic roller carries negatively charged toner to the latent image on the drum surface.

4)Transfer : The transfer rollers opposite the OPC drums transfer toner from the drums to the transfer media (e.g. paper, OHP film, etc).

5)Cleaning for OPC drum: The cleaning blade removes remaining toners on the drum surface after image transfer to the paper.

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2-14

2. Product Specifications

2) Toner Cartridge

By using the electronic photo process, it creates a visual image. In the toner cartridge, the OPC unit and the developing 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).

•Operation condition : Temp 10~30 , Humidity 20~85% RH

•Developing Method : Non magnetic 1 element contacting method

•Toner : Non magnetic 1 element shatter type toner

•The life span of toner (ISO 19752 pattern / A4 standard)

-Initial toner : 7K

-Sales toner : 7K / 15K

•Toner Residual Sensor : Dot count with CRUM

•OPC Cleaning : Collect the toner by using cleaning blade

•Handling of wasted toner : Collect the wasted toner in the cleaning frame by using cleaning blade

•OPC Drum Protecting Shutter : None

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

aCharge Roller

bDrum OPC

cCleaning Blade

dDoctor Blade

eDeveloper Roller

f Supply Roller

gCharge Cleaning Roller

hAgitator 1

i Agitator 2

2-15	Copyright© 1995-2011 SAMSUNG. All rights reserved.

2. Product Specifications

2.2.4.3. Fuser unit

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

1)Thermostat

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

•Thermostat Type : NonContact type

•Control Temperature : 170 ± 5

2)Thermistor

It is a temperature detecting sensor.

•Temperature Resistance : 7 (180 )

3)Heat roller

The heat roller transfers the heat from the lamp 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)Halogen Lamp

•Voltage : 120 V, 115 ± 5 % / 220 V, 230 ± 5 %

•Capacity : 850 Watt ± 25 W

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2-16

2. Product Specifications

2.2.4.4. LSU (Laser Scanning 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.

OPC Drum

Photo Diode
	Polygon Mirror
	Polygon Motor
LD Driver circit	Motor Driver
LD(Laser Diode)
Protector panel

2-17	Copyright© 1995-2011 SAMSUNG. All rights reserved.

2. Product Specifications

2.2.5. Hardware Configuration

The ML-3750 series Electrical Circuit System consists of the following:

•Main board

•OPE board

•SMPS board

•HVPS board

•SCF board (Optional)

Diagram of the ML-3750 Series Electrical Circuit

The Main Controller controls all modules required to print, that is, LSU, HVPS, SMPS, FAN, Fuser, etc.

The Main Controller receives print data from the host through network or USB Port. It takes this information and generates printable video bitmap data. Engine and Video Controller are not separated.

The Main Controller adopts the Chorus3N (533 MHz) CPU, on board DDR3 memory to perform printing jobs successfully. The OPE Controller displays the status of the system using 16 x 2 line LCD in response to user actions or the Main controller. The HVPS supplies high voltage for developing Process. High Voltage controlled by PWM signal from CPU.

The SMPS makes +5V and +24V DC from 220V or 110 AC.

Copyright© 1995-2011 SAMSUNG. All rights reserved.

2-18

2. Product Specifications

2.2.5.1. Main board

ML-3750 series Main board is composed with below components.

•Chorus3N : To generate the printable video data and control engine Embedded USB2.0 device, Host channel

•System memory - 1CH DIMM PBA DDR3 128MB (Default)

•Giga Ethernet PHY : Network printing

•Serial Flash (16MB) : Program memory

The Main Controller manages an Electro-photography system, controls the Video Data of printing images from Main Board to LSU, provides high-voltages and PWMs, adjusts temperature in the fusing system, reads sensor signals and controls SCF option.

The Main controller also controls OPE and Giga N/W PHY, USB Device.

[Main board diagram]

2-19	Copyright© 1995-2011 SAMSUNG. All rights reserved.

2. Product Specifications

[Main board image]

•Connection

1	HVPS		9	Parallel Option DC supply		17	SMPS Power
2	Paper Empty, Regi, Feed			jack		18	MP
	sensor		10	Debug
						19	LSU
3	OPE
			11	Exit Sensor		20	FAN MAIN
4	CRUM
			12	FAN SMPS		21	DDR3 SODIMM
5	THERMISTOR
			13	Air temperature
6	Outbin Full Sensor & Rear
			14	Main Motor & Clutch
	Cover
			15	SCF
7	N/W
8	USB Device		16	SMPS Signal

•Information

-Part Code : JC92-02469A

-PBA Name : PBA-MAIN

Copyright© 1995-2011 SAMSUNG. All rights reserved.

2-20

2. Product Specifications

2.2.5.2. OPE board

The OPE board is composed of an OPE MICOM(STM8SP103K3MAFTR), two status LED, ECO LED, power LED, four navigation LED, 16x2 line LCD and some keys. OPE communicates with main controller via UART.

[OPE board diagram]

[OPE board image]

•Information

-Part Code : JC92-02468A

-PBA Name : OPE-LCD

2-21	Copyright© 1995-2011 SAMSUNG. All rights reserved.