Samsung SCX-4725FN, SCX-4725F Service Manual

SCX-4725FN/XEP

Basic Model : SCX-4725FN

SERVICE Manual

DIGITAL LASER MFP

The keynote of Product

- Machine Life: 50,000Pages - Cpu: Chorus M

- Device Memory: 32MB

- Resolution: 1200x1200dpi - Option: N/A

- Printing Speed: 24ppm(A4, LTR) - Print Language: PCL

- Path Type: C-Path

- Cassette Capa.: 250sheets

- Outlet Stacking Capa.: 100sheets

- Toner Cartridge: initial(1.5K), sales(3K) - ADF Capacity: 30sheets

- Scan Method: 600 dpi Color CIS

- Copy Speed: SDMC: 22Cpm/Ltr, MDMC: 7Cpm/Ltr

- Interface: USB2.0

SCX-4725FN Series

Contents

1.Precautions

1.1Safety Warning 1-1

1.2Caution for safety 1-2

1.3ESD Precautions1-5

1.4Super Capacitor or Lithium Battery Precautions 1-5

2.Product spec and feature

2.1Product Specifications 2-1

2.1.1Product Overview 2-1

2.1.2Specitications 2-2

2.1.3Model Comparison Table 2-9

2.2System Overview 2-10

2.2.1System Layout 2-10

2.2.2Engine H/W Specification2-14

2.2.3Develope Process2-21

2.2.4Sanner Part 2-22

2.2.5OPE(Operational Panel Equipment) 2-24

2.2.6SMPS & HVPS 2-25

2.2.7 FUSER AC POWER CONTROL

2-27

3.Disassembly and Reassembly

3.1General Precautions on Disassembly 3-1

3.2MP Tray 3-2

3.3Pick Up Roller 3-3

3.4Front Cover 3-3

3.5Cassette Tray 3-4

3.6Rear Cover 3-5

3.7Right Cover 3-6

Continued

3.8Left Cover 3-7

3.9Scan Ass'y 3-8

3.10ADF Housing 3-9

3.11OPE Unit 3-11

3.12Platen Housing 3-12

3.13Middle Cover 3-14

3.14HVPS 3-15

3.15Main PBA3-16

3.16RX Drive 3-17

3.17Fuser Unit 3-18

3.18Engine Shield (With LIU PBA, SMPS) 3-21

3.19LSU 3-22

3.20Paper Path Frame 3-23

3.21CRUM Harness 3-25

4.Troubleshooting

4.1Alignment and Adjustments 4-1

4.1.1User Mode 4-1

4.1.2Tech Mode and Setting 4-4

4.1.3Control Panel 4-13

4.1.4LCD Status Error Message 4-15

4.1.5Engine Test Mode 4-17

4.1.6Paper Path and Clearing Paper Jams 4-19

4.2Troubleshooting4-25

4.2.1Checking Symptoms 4-25

4.2.2Bad discharge 4-28

4.2.3Set Malfunction – Causes and Solutions 4-32

4.2.4Bad Software Environment 4-36

4.2.5Bad image 4-40

4.2.6 Fax & Phone Problems

4-47

4.2.7 Copy Problems 4-51

Continued

4.2.8 Scanning Problems – Causes and Solutions

4-53

4.2.9Toner Cartridge Service 4-54

4.2.10Software Problems – Causes and Solutions 4-56

4.2.11Windows Problems 4-61

4.2.12SyncThru Installation Problems4-62

5.Exploded Views & Parts List

5.1Main 5-2

5.2Cover Housing5-4

5.3Front Cover 5-6

5.4Rear Cover 5-8

5.5Frame Ass'y 5-10

5.6ADF Ass'y 5-12 5.6-3-2 ADF Ass'y Part (Additional) 5-13

5.7 Platen Cover Ass'y

5-16

5.8Platen Ass'y 5-18

5.9OPE Unit 5-20

5.10RX Drive Unit 5-22

5.11MP Tray 5-24

5.12Fuser Unit 5-26

5.13Paper Path Ass'y5-28

5.14 Pick UP Unit

5-30

6.System Diagram

6.1Block Diagram6-1

6.1Connection Dia ram 6-2

Continued

7.Reference Information

7.1Troubleshooting Tool 7-1

7.2Acronyms and Abbreviations 7-2

7.3Selecting printer locations 7-4

7.4Sample Tests Patterns 7-5

Precautions

11. 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 GEÖFFNET.
	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 LASERSTRÅLNING VED ÅBNING, NÅR
		SIKKERHEDSBRYDERE ER UDE AF FUNKTION.
		UNDGÅ UDSAETTELSE FOR STRÅLNING.
ADVARSEL. - USYNLIG LASERSTRÅLNING NÅR DEKSEL
		ÅPNES. STIRR IKKE INN I STRÅLEN.
		UNNGÅ EKSPONERING FOR STRÅLEN.
VARNING		- OSYNLIG LASERSTRÅLNING NÄR DENNA DEL
		ÄR ÖPPNAD OCH SPÄRREN ÄR URKOPPLAD.
		BETRAKTA EJ STRÅLEN. STRÅLEN ÄR FARLIG.
VARO! - AVATTAESSA JA SUOJALUKITUS OHITETTAESSA
		OLET ALTTIINA NÄKYMÄTTÖMÄLLE LASER-
		SÄTEILYLLE ÄLÄ KATSO SÄTEESEEN.

Samsung Electronics	Service Manual	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 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 otherwise 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 recommend 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.

	1-2	Service Manual
		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 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.

Samsung Electronics	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 11.2kg including toner cartridge and cassette. Use safe lifting and handling techniques. Back injury could be caused if you do not lift carefully.

(4) Ensure the printer is installed safely.

The printer weighs 11.2Kg, 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	Service Manual
		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 compa-

rable 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.

1.4 Super Capacitor or Lithium Battery Precautions

1.Exercise caution when replacing a super capacitor or Lithium battery. There could be a danger of explosion and subsequent operator injury and/or equipment damage if incorrectly installed.

2.Be sure to replace the battery with the same or equivalent type recommended by the manufacturer.

3.Super capacitor or Lithium batteries contain toxic substances and should not be opened, crushed, or burned for disposal.

4.Dispose of used batteries according to the manufacture’s instructions.

Samsung Electronics	Service Manual	1-5

Product specification and feature

22. Product specification and feature

2.1 Product Specifications

2.1.1 Product Overview

Item	Descriptions	Remark
Basic Model	SCX-4725FN(4-in-1 Flatbed MFP)
	SCX-4725F(4-in-1 Flatbed MFP)
Target User	SOHO, Economical(Speed/Price) Customer
Customer Benefits	- Compact Size
(Sales Points)	- 24ppm/A4, 24ppm/Letter fastest speed in its price class
	- Favorite Copy
	- ID Card Copy
	- Toner Save
	- up to 24ppm/A4(Up to 24ppm/Letter)
	- 250 sheets Multi-Purpose type paper input/100 sheets Paper Output
	- 3,000pages toner capacity
	- 600dpi Print/Copy Resoulusion
	- Samsung Print Language
	- 32MB System memory
	- 30 ADF
	- 33.6 Kbps Fax Modem
	- 100 Speed Dial
	- 72 Hour Battery Back-up

Samsung Electronics	Service Manual	2-1

Product specification and feature

2.1.2 Specitications

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

2.1.2.1 General Specitications

Item			Descriptions (SCX-4725FN / SCX-4725F)
Major Features			Copier, Print, Scan, Fax(SCX-4725FN)
Net Dimension (WxDxH)			438(W)*374(D)*368(H)(17.2x14.7x14.5")
Net Weight (Inc. Toner Cartridge)			11.2kg
CPU			Chorus-M (300MHz)
LCD			2 Line x 16 characters / 2Line x 8 characters(for china and korea)
Toner Save			Yes (With toner save button)
I/O Interface			USB2.0
Network Interface			Yes
OS Compatibility			Windows 98/Me/NT4.0/2000/XP, Various Linux OS (via USB interface only) including
			Red Hat 8.0~9.0, Fedora core 1~3, Mandrake 9.0~10.2, and SuSe 8.2~9.2, Mac 10.3
Power Requirement			110 ~ 127 VAC, 50/60 Hz, 5.5A
			220 ~ 240 VAC, 50/60 Hz, 3A
Power Consumption			Sleep Mode : Under 12W
			Standby Mode : 70W
			Average : 400W (Print Mode)
Energy Star Compliant			Yes
Power Switch			Yes
Noise		Warm up	49 dBA
		Stand by	35 dBA
		Coping	55 dBA
		Printing	53dBA
Warm up time		from Power On Status	Less than 30 seconds
		from Sleep Mode	Less than 30 seconds
		(Recovery time)
Max. Monthly		Print	10,000 pages
Volume		Scan	ADF: 2,500 pages, PLATEN: 1,700 pages
Average Monthly Print Volume			700 pages
Average Monthly Scan Volume			150 pages
Machine Life		ENGINE	5 years or 50,000 Pages. Whichever comes first
		SCANNER	ADF : 30,000 Pages, Platen : 20,000 Pages
Operation		Temperature	10°C ~ 32 °C (50°F ~ 89°F)
conditions		Humidity	20 % ~ 80 % RH
Approval			Class B
Device Memory			32MB
Page Counter			Yes
Print Configuration Sheet(System Data)			Yes

2-2 Service Manual

Samsung Electronics

Product specification and feature

2.1.2.2 Print Specifications

	Item	Descriptions (SCX-4725FN / SCX-4725F)
Method		Laser Beam Printing
Speed		Up to 24ppm in A4 (24ppm in Letter)
Emulation		PCL
Power Save		Yes(Interval option: 5, 10,15, 30, 45 minute)
Resolution	Normal	1200 x 1200 dpi
	RET	-
Memory		32MB
First Print Out	From Stand by	Approx. 10 seconds
Time	From Cold Status	Less than 30 seconds
Duplex	Print	Manual
WHQL Compliant		Window XP
Printable Area		A4: 201.6x288.6mm
		LTR: 207.6x270.6mm
		Legal: 207.6x347.6mm
		Folio: 207.6x322.6mm
Halftone (Gray Scale)		256 levels

2.1.2.3 Scan Specifications

	Item	Descriptions (SCX-4725FN / SCX-4725F)
Compatibility		Twain standard / WIA Standard (Window 2000/XP)
Scan Method		600dpi Color CIS(Contact Image Sensor) Module
PC Scan Speed Lineart, Halftone		10sec Platen(13sec ADF)
through Platen	Gray	23sec Platen (26sec ADF)
	Color 300dpi	65sec Platen(70sec ADF)
Resolution	Optical	600 x 600 dpi
	Enhanced	4800 x 4800 dpi
Halftone		256 levels
Scan Size	Max. Document Width	Max.216mm (8.5")
	Effective Scan Length	297 mm (11.7")
	Effective Scan Width	Letter/Legal: 208mm(8.2")A4: 202mm
Scan-to	Button	Yes
	Application	Yes
Scan Depth	Color	24 bit
	Mono	1bit for Line art, Halftone, 8 Bit for Gray scale

Samsung Electronics	Service Manual	2-3

Product specification and feature

2.1.2.4 Copy Specifications

	Item	Descriptions (SCX-4725FN / SCX-4725F)
Copy Speed		Up to 22ppm in A4 (22ppm in Letter)
Resolution	Optical	600*600 dpi (Scan:600*600dpi, Print: 600*600dpi)

-Text & Text/Photo mode : 600*300dpi(ADF, Platen)

-Photo mode : 600*600dpi (Platen), 600*300dpi(ADF)

		Enhanced	-
First Copy		Stand by	Approx. 16 seconds(ADF), Approx. 11 seconds(Platen)
Out Time		From Power Save Mode	Approx. 46 seconds(ADF), Approx. 40 seconds(Platen)
		(110V only)
Original Image type selection			Text, Text/Photo, Photo
Zoom Range			25-400%(Platen), 25-100%(ADF)
Multi Copy			1~99 Pages
Preset			[Original(100%)], [A4	A5(71%)], [LGL LTR(78%)], [LGL A4(83%)],
			[A4 LTR(94%)], [EXE	LTR(104%)], [A5 A4(141%)], 25%, 50%, 150%
			200%, 400%, [Custom: 25-400%)]
Darkness Control			3 level (Light, Normal, Dark)
Auto return to default mode			Yes (after 1 minute)- Time out option: 15, 30, 60, 180 sec., Off
Changeable Default mode			Darkness, Original Type, Reduce/Enlarge, No. of Copies
ID Card Copy		2-up	Yes (ADF Only)
		4-up	Yes (ADF Only)
		Collation	Yes (ADF Only)
		Autofit	Yes (Platen Only)
		LD Card Copy	Yes (Platen Only)
		Clone	Yes (Platen Only)
		Poster	Yes (Platen Only)

2-4 Service Manual

Samsung Electronics

Product specification and feature

2.1.2.5 Telephone Specifications

	Item	SCX-4725FN
Handset		No
On hook Dial		Yes
Search		Yes(Phone Book)
1-Touch Dial		10 ea (0~9)
Speed dial		90 locations(10~99)
TAD I/F		Yes
Tone/Pulse		Tone Default, Pulse Changing in Tech Mode
Pause		Yes
Auto Redial		Yes
Last Number Redial		Yes
Distinctive Ring		Yes
Caller ID		No
Extention Phone Interface		Yes
Report & List	Tx/Rx Journal	Yes
Print out	Confirmation	Yes
	Help List	No
	Auto Dial List	Yes
	System Data	List all user setting
Sound Control	Ring Volume	Yes(Off,Low,MED,HIGH)
	Key Volume	Yes(On,Off)
	Alarm Volume	Yes(On,Off)
	Speaker	Yes(On,Off, Comm)

Samsung Electronics	Service Manual	2-5

Product specification and feature

2.1.2.6 Fax Specifications

Item					SCX-4725FN
Compatibility					ITU-T G3
Modem Speed					33.6Kbps
TX Speed					3sec
Compression					MH/MR/MMR/JBIG
Color Fax					Yes(Tx Only)
ECM					Yes
Resolution			Std		203x98dpi
			Fine		203x196dpi
			S.Fine		300x300dpi
			Photo		203x196dpi
			Color		200x200dpi
			Auto Switching		Yes
Scan Speed			Standard		approx. 3sec (ADF)
					approx. 5sec (Platen)
			Fine		approx. 7sec (ADF)
					approx. 8sec (Platen)
			S.Fine		approx. 7sec (ADF)
					approx. 8sec (Platen)
Rx fax duplex print out					No
Multiple page scan speed					7 cpm / Ltr (Standard Resoution Res.)
(Memory Tx.)
Receive Mode					Fax, TEL, Ans/Fax, DRPD
Memory			Capacity		2MB (When Power off Memory Back up)
			Optional Memory		No
			Max locations to store		99 locations
			to 1 Group Dial
			Fax Forward		Yes(On/Off)
			Broadcasting		109 locations(Max locations)
			Cover page		NO
			Delayed fax		Yes
			Memory RX		Yes
Functions			Voice Request		No
			TTI		Yes
			RTI		Yes
			Polling		No
			Earth/Recall		No
			Auto Reduction		Yes
			RDS		Yes
Junk Fax barrier					Yes
Security Receive					Yes
Memory Back-up					Max. 72hours

2-6 Service Manual

Samsung Electronics

Product specification and feature

2.1.2.7 Paper Handling Specifications

Item			SCX-4725FN / SCX-4725F
Input Capacity and Types	250-sheet Cassette Tray (75 g/ , 20 lbs)
Output Capacity and Types	100-sheet Face Down(75 g/		, 20 lbs)
Manual Tray	1 sheet
Media size	A4, A5, A6, Letter, Legal, Folio, Executive, ISO B5, JIS B5, Monarch, Envelope, No.10, DL, C5, C6
	76 x 127 mm (3" x 5") ~ 216 x 356 mm (8.5" x 14")
Media Type	Plain Paper, Transparency, Label, Envelope, Tick, Thin, Bond, Color Paper, Card Stock, Preprinted
Paper Weight	16~24lb (60 to 90g/	), Cassette Tray
	16~43lb (60 to 165g/	) for 1 sheet, Manual Tray
ADF Capacity	Up to 30 sheets of 20lb(75g/		) paper
ADF Document Size	Up to Legal

2.1.2.8 Software Specifications

		Item	SCX-4725FN / SCX-4725F
Compatibility		DOS	No
		Win 3.x	No
		Win 95	No
		Win 98/ME	Yes
		Win NT 4.0	No
		Win 2000	Yes
		Win XP	Yes
		Mac	Yes (10.3 )
		Linux	Yes
Driver		Printer	PCL
		TWAIN	Yes
		WIA	Yes
		ScanToPC	Yes
		PC-FAX	Yes (Send only)
Application		RCP	Yes
		Status monitor	Yes
		SmarThru4	Yes

Samsung Electronics	Service Manual	2-7

Yes (include Setup Guide and Function Guide)

Yes (Korea Only)

3 CD (Contents; Electronic User Manual, SmarThru, Print Driver, Twain Driver, RCP)

1 EA

1 EA

No 1 EA

No No

Yes Yes

SCX-4725FN / SCX-4725F

Single Cartridge

Front door open and front loading

3,000 pages at ISO 19752 Std. Coverage(Ships with 1,000 pages Starter Toner Cartridge)

SCX-4525D3

-

Samsung Electronics

SCX-4725F

SCX-4725FN

Product specification and feature

2.1.2.9 Accessory

Item

Quick Setup Guide

Quick User Guide

S/W CD ROM

Toner Cartridge

Power Cable

Telephone Jack

Printer Cable

Tray Coner

2.1.2.10 Consumables

Item

Type

Toner Yield

Code

Level Sensor

2-8 Service Manual

Electronics Samsung

Manual Service

9-2

	Item	SCX - 4725FN	Brother MFC 7820N	HP LJ 3055	Canon MF 5770
		(Whitney-2 24ppm)

Model Image

		Speed	24 ppm/A4 (25ppm/Ltr)	20 ppm/A4 (20ppm/Ltr)	18 ppm/A4 (19ppm/Ltr)	20 ppm/A4 (21ppm/Ltr)
	Print	Resolution	1200 x 1200 dpi	2400 x 600 dpi	Up to 1200 x 1200 dpi	1200 x 600 dpi quality
		Emulation	PCL6, PS3	PCL6, PS3	PCL6, PS3	GDI
	Copy	Speed	24 ppm/A4 (25ppm/Ltr)	20 ppm/A4 (20ppm/Ltr)	18 ppm/A4 (19ppm/Ltr)	20 ppm/A4 (21ppm/Ltr)
		Resolution	600 x 600 dpi	600 x 300 dpi	600 x 600 dpi	600 x 600 dpi
	Scan	Resolution (Optical)	600 x 2400 dpi	600 x 2400 dpi	Up to 600 dpi	1200 x 2400 dpi
		Modem Speed	33.6 Kbps	33.6 Kbps	33.6 Kbps	33.6 Kbps
	Fax	Memory	Approx. 320 pages	Approx. 600 pages	2 MB (Up to 110 pages)	Approx. 256 pages
		Auto Dial	1-touch 10 / Speed 190	208 Locations	119 Locations	Speed 12 / Coded 100
	Paper	Input Capacity	250 -sheet MP Tray	250 - sheet CST Tray	250 -sheet MP Tray	250sheet CST Tray
		ADF Capacity	30 sheets	35 sheets	50 sheets	50 sheets
		Net Dimension	438 x 374 x 368mm (TBD)	432 x 395 x 294 mm	497 x 406 x 393 mm	486 x 477 x 442mm
	General
		Interface	USB 2.0,	USB 1.1, IEEE 1284,	USB 2.0,	USB 2.0,
			Ethernet 10/100 Base TX	Ethernet 10/100 Base TX	Ethernet 10/100 Base TX	Ethernet 10/100 Base TX
		Type	Single Cartridge	2-piecese Cartridge	Single Cartridge	Single Cartridge
	Cons.	Yield	3 K (Starter 1.5K)	Toner 2,5K/ Drum 12K	2K	2.5 K
				(Starter 1,5K/ 12K)

Table Comparison Model 3.1.2

feature and specification Product

Product specification and feature

2.2 System Overview

2.2.1 System Layout

The SCX-4725FN/4725F is roughly made up Main Control part, Operation Panel part, Scanner part, Line Interface part and Power part. Each Part is separated Module which focus on common and standard design of different kind products. main control part adopting Fax & LBP Printer exclusive Controller is chorus-M CPU(ASIC) and 1 Board. Scanner part is composed of ADF and Platen and is connected with Main by Harness.

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Product specification and feature

2.2.1.1 Feeding section

There is a universal cassette which automatically loads paper and the manual feed which supplies paper single sheet at a time. The cassette has a friction pad which separates paper to ensure single sheet feeding, and it has a sensor, which checks when the paper tray is empty.

- Feeding Method: MP Cassette Type

- Feeding Standard: Center Loading

- Feeding Capacity: Cassette-150 sheets (75g/m2, 20lb paper standard) Manual 1 sheet (Paper, OHP, Envelop, etc.)

- Paper detecting sensor: Photo sensor - Paper size sensor: None

2.2.1.2 Transfer Ass’y

This consists of the PTL (pre-transfer lamp) and the Transfer Roller. The PTL shines a light onto the OPC drum. This lowers the charge on the drum’s surface and improves transfer efficiency.

The transfer roller transfers toner from the OPC drum surface to the paper.

- Life expectancy: Over 50,000 sheets (at 16~30°C)

2.2.1.3 Driver Ass’y

- Gear driven power unit. The motor supplies power to the paper feed unit, the fuser unit, and the toner cartridge.

2.2.1.4 Fixing Part(Fuser)

-The fuser consists of the Heat Lamp, Heat Roller, Pressure Roller, Thermistor, and Thermostat. It fixes toner to the paper using pressure and heat to complete the printing job.

2.2.1.4(a) Temperature-Intercepting Device (Thermostat)

The thermostat is a temperature sensing device, which cuts off the power to the heat lamp to prevent overheating fire when the heat lamp or heat roller overheats.

2.2.1.4(b) Temperature Detecting Sensor (Thermistor)

The Thermistor detects the surface temperature of the heat roller, this information is sent to the main processor which uses this information to regulate the temperature of the heat roller.

2.2.1.4(c) Heat Roller

The surface of the Heat Roller is heated by the Heat Lamp. As the paper passes between the Heat and Pressure rollers the toner is melted and fixed permanently to the paper. The surface of the roller is coated with Teflon. This ensures that toner does not adhere to the roller surface.

Samsung Electronics	Service Manual	2	-11

Product specification and feature

2.2.1.4(d) Pressure roller

The Pressure Roller mounted under the heat roller, it is made of a silicon resin, and the surface of the roller is coated with Teflon. This ensures that toner does not adhere to the roller surface.

2.2.1.4(e) Safety Features

•To prevent overheating

-1st protection device: Hardware cuts off when overheated

-2nd protection device: Software cuts off when overheated

-3rd protection device: Thermostat cuts off mains power to the lamp.

•Safety device

-Fuser power is cut off when the front cover is opened

-LSU power is cut off when the front cover is opened

-The temperature of the fuser cover's surface is maintained at less than 80°C to protect the user and a caution label is attached where the customer can see it easily when the rear cover is opened.

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Product specification and feature

[Case part figure]

STACKER

COVER-M_MIDDLE

COVER-M-SIDE R

COVER-M_JAM

EXTEND-SMALL

EXTEND-LARGE

COVER-M_REAR

TRAY CASSETTE

FIXING BKT

SPEKER

COVER-M_DEVE

COVER-M-SIDE-L

[Scan part figure]

MOTOR

ASS'Y CIS

SCAN

UPPER

SCAN

LOWER

TIMING

BELT

ADF

GLASS

SCAN

GLASS SLIDER -CIS

KEY & OPE

COVER

Samsung Electronics	Service Manual	2	-13

Product specification and feature

2.2.2 Engine H/W Specification

1)Recording Method : LSU(Laser Scanning Unit)

2)Printing Speed : 24ppm

(In continuing printing base Letter, printing pages from 2nd to last during 1min)

3)Recording Density : 1200 dpi

4)Cassette Capa. : Cassette ; 250sheets(75g/ Base), 1-sheet Feeding : N/A((DRIVE Selection : Paper, OHP, Envelop - 1 sheet)

5)Manual Tray : All paper 1 sheet

6)Paper Size : Cassette ,Manual ; Width = 76 ~ 216mm, Length = 125mm ~ 356mm

7)Effective recording size

-A4 :202 x 291 mm

-Letter : 208 x273mm

-Legal : 208 x 350 mm

-Folio : 208 x 325 mm

-TopMargin: 2 2 mm

-Left, Right Margin : 2 2 mm

8)CRU(Toner Cartridge)Life : 3,000pages Printing(A4, ISO Standard Pattern Printing)

9)First Print Out Time : within 11sec ( Standby )

10)Warming up time : within 35sec (Ambient : 25 °C)

2.2.2.1 Main Board Control Part

Main control part of SCX-4725FN is made of ASIC(CPU, Image processor, PC I/F part include, Scan interface part, FAX Modem part and Printing process I/F part. CPU handles the BUS control, I/O interface, scan interface, PC interface and other miscellaneous driver circuit.

1)Main Board

-Main Board has a function of sending Current Image Video Data to LSU of the machine, controlling motor Driving Circuit and monitoring Paper Exit Sensor, Cover Open switch, OPE Panel Inputs.

2)Main Controller

-CPU : Chorus-M is the main CPU and is made up on the 32bit RISC architecture using ARM 920T core. Main CPU controls the whole system according to the program code which stored in the FlashROM memory.

-Operation Frequency : CPU Core -> over 300MHz, System Bus -> 100MHz

-Summary of the Key Function Block:

1.3V for internal Core, 3.3V for I/O Pad with 16KB I-Cache and 16KB D-Cache.

Image Processor included.

On-Chip clock generator with PLL.

Memory and External Bank Control.

DMA Control (16-Channel)

Interrupt Control.

2-port USB Host/1-port USB device(ver 1.1) interface control.

Parallel interface control.

UART(1-Channel)

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Product specification and feature

Synchronous Serial Interface Control.

A/D Converter(10-bit, 8channel).

General I/O Port control.

RTC with calendar function.

S/W Assistant function(Rotator)

-Flash Memory : Stores system program and can be updated to the newer system program code through the PC interface. It stores the FAX Journal List, One Touch dial number, speed dial number, and machine

configuration setup data.

Capcity : 16 Mbyte (NOR Type)

Access Time : 70 nsec

-SDRAM : SDRAM is used for Print Buffer, Scan buffer when scanning, ECM Buffer when FAX Receiving,

and system working memory.

Capacity : 32 Mbyte

Access Time : 166MHz(Max)

Data Backup : 48 Hours

Backup Battery Charging Time : 100hours when completely discharged.

2.2.2.2Scan Part

1)Image Signal Input Part

-Image Signal from CIS has a level of about 1.2V and is goes to ADC of Chorus2. After ADC, CIS analog signal will be converted to 8-bit Digital signal.

2)Image Processing

-On the surface of the original paper, the light from the CIS LED reflected and goes to the CIS Sensor. Then the light is converted to the appropriate voltage suitable for ADC input. Analog signal from CIS sensor is used for ADC input then is converted to 8-bit digital data. Image processor of the Chorus2 will do the Shading correction function at first, then Gamma correction function next. After then, the data goes to different module according to the copy or FAX resolution mode. When Text mode, the image data goes to LAT module, when Photo mode, the image data goes to Error Diffusion module, when PC-Scan mode, the image data goes directly to the PC through DMA access.

Summary of the Image sensor interface is as below;

-Minimum Scan Line Time :1.5ms

-Scan Resolution : 600*600 dpi

-Scan Width : 208mm

-Function

White Shading Correction

Gamma Correction

CIS Interface

256 Gray Scale

3) CIS Driving Part

Samsung Electronics	Service Manual	2	-15

Product specification and feature

-CIS Supply Voltage : +3.3V

-CIS Max frequency : 5MHz

-CISLinetime

Fax/Copy - 1.5ms

PC-Scan - 4.5ms

-White output volt. : Max 0.8V

4)ADF Driving Part : Driving ADF Stepper motor, and the maximum motor speed is 2000PPS.

-MOTOR DRIVER : A3978(Allegro)

-Driving Voltage : 24V DC

-Phase : 2-2 Phase 2000PPS at Quick Scan,

2-2 Phase 1000PPS AT Fine Scan,

2-2 Phase 667PPS AT Super Fine Scan

2.2.2.3 FAX Section

Modem Part

BLOCK DIAGRAM

Implemented by based on Conexant DAA (Data Access Arrangement) Solution, and is roughly composed of two kinds Chip Solution

-CX86710 (SFX336): Existing Modem Chip which adds SSD (System Side Device) for interfacing between LSD and DIB of FM336Plus Core

-CX20493 (LSD) : LIU (Line Interface Unit) Chip which is controlled by SSD and satisfies each PSTN Requirements by modulating internal Configuration with connecting Tel Line.

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Product specification and feature

Modem (SFX336) specification.

2-wire half-duplex fax modem modes with send and receive data rates up to 33,600 bps

V.17, V.34, V.29, V.27 ter, and V.21 Channel 2

Short train option in V.17 and V.27 ter

PSTN session starting

V.8 and V.8bis signaling

HDLC support at all speeds

Flag generation, 0-bit stuffing, ITU CRC-16 or CRC-32 calculation and generation

Flag detection, 0-bit deletion, ITU CRC-16 or CRC-32 check sum error detection

FSK flag pattern detection during high-speed receiving

Tone modes and features

Programmable single or dual tone generation

DTMF receiver

Tone detection with three programmable tone detectors

Receive dynamic range:

0 dBm to -43 dBm for V.17, V.29, V.27 ter and V.21 Channel 2

9dBm to -43 dBm for V.34 half-duplex

Digital speaker output to monitor received signal

Two16-byte FIFO data buffers for burst data transfer with extension up to 255 bytes

V.21 Channel 1Flag detect

V.21 Channel 1Flag detect

+3.3V only operation

Typical power consumption

Normal mode: 264 mW

Samsung Electronics	Service Manual	2	-17

Product specification and feature

Signal Transition of DAA Solution

Line Interface Signal of Tel Line and LSD is Analog Signal.

2)there is A/D, D/A Converter in LSD, so Analog Signal from Tel Line is converted in Digital through A/D Converter in DAA and transfer to SSD by DIB Capacitor

Digital Signal from SSD is converted to Analog by D/A Converter in DAA and transfer to Tel Line

Transformer transfer Clock from SSD to LSD and Clock Frequency is 4.032MHz.

LSD full wave rectifies Clock to use as inner Power supply and also use as Main Clock for DIB Protocol Sync between LSD and SSD. Transformer transfer Clock by separating Primary and Secondary, and

amplifies Clock Level to LSD by Coil Turns Ratio 1:1.16.

Clock

- Clock is supplied by transformer from SSD to LSD, and there is PWROUT to adjust output impedance of Clock

Out Driver is inside SSD and CLKSHIGH Resistor to adjust duty of HLPWR Resistor and Clock.

	CLKP
SSD								LSD
	CLKN
	DIBP
	DIBN

Clock from SSD to LSD has Differential structure of 180 phase difference for Noise Robustness

DIB Data transfer Data from SSD to LSD by Transformer, and also transfer specific data from LSD to SSD.

After transferring data from SSD, RSP is transferred and LSD recognizes RSP and change LSD to output Driver transfer Data to SSD.

DIB Data form SSD to LSD by Transformer has Differential structure of 180 phase difference between DIBP and DIBN for Noise Robustness

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Product specification and feature

2.2.2.4 Line Interface Part

This is Connection Part between system and PSTN(Public Switched Telephone Network), and primary circuit is usually located. Main functions are Line Interface, Telephone Connection and Line Condition Monitoring.

1 Telephone Line Connection

Modular Plug : RJ-11C

LIU PBA Modular Type : 623 PCB4-4

Line Code Length : 2500 50mm

Line Code Color : Black

ON HOOK state Characteristic 1) DC Resistance

DP Dial Mode (Direct Current 30mA) : 50 ~ 300ohm

DTMF Dial Mode (Direct Current 20mA) : 50 ~ 540ohm

2) Ring Sensitivity

Ring detection Voltage : 40Vrms 150Vrms (condition :Current=25mA,Frequency=15Hz) product Margin : 30Vrms 150Vrms

Ring detection Frequency : 15.3Hz 68Hz (condition : Voltage=45Vrms,Current=25mA ) product Margin : 15Hz 70Hz

Ring detection Current : 20mA 100mA (condition : Voltage=40Vrms,Frequency=20Hz) product Margin : over 15mA

3) False Ring Sound

Ring Frequency : 750 Hz + 1020 Hz

Ring interrupt Cycle : On/Off depending on input Ring Signal Cycle.

Samsung Electronics	Service Manual	2	-19

Product specification and feature

2.2.2.5 Printing Part

Printing Process part is made of PC-Interface part, PVC(Priter Video Controller), LSU control part, High Voltage control part and Fuser Unit control part. PC-interface core is included in the Chorus2 ASIC and controls the PCinterface. LSU control part controls the LSU polygon motor, Laser diode, video data output so thatthe printing image can be made up on the OPC Drum.

2.2.2.6 Engine Paper Feeding

1)Feeding Type : MP Cassette Type

2)Feeding Standard : Center Loading

3)Feeding Qty : Cassette 150 sheets (75g/, 20lb paper standard)

4)1 sheet (Paper, OHP, Envelope etc.)

5)Separating Type: Cassette - Friction Pad Type

6)Manual Tray : 1 sheet

7)Driver Type : Driving by Gearing from Main Motor

8)Pick_up Roller Driver : Solenoid

9) Pick up Roller Rubber Material : EPDM+IR =1.3 or more

10)Pick up Velocity : 94.8731mm/Sec (Process : 93.0667mm/sec)

11)Paper detecting Sensor : Photo Sensor

12)Paper Size Sensor : None

13) Paper Separating Pad Material : NBB 52 °, =0.8~1.2

14)Separating Pad Pressure : TBD 150 gf

15)Pick_up Roller RPM : 47.683 RPM

16)Feeding Pressure (Same as Transfer Roller)

17)Paper Exit Type : Face Down

18)Feed Roller Force : TBD Kg.f or more.

19)Spring Feed Tensile Force : TBD gf

20)Feed roller Velocity : mm/sec

21)Feed Roller Material

22)Exit Sensor : Photo Sensor

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