Samsung SCX-4321, SCX-4521F Service Manual
DIGITAL LASER MFP
SCX-4521F Series
SCX-4321/XEV
Basic Model :SCX-4521F
Manual
SERVICE
DIGITAL LASER MFP The keynote of Product
- Machine Life: 50,000Pages
- Cpu: Chorus2
- Device Memory: 16MB
- Resolution: 600*600dpi
- Option: N/A
- Printing Speed: 22ppm/LTR,20ppm/A4
- Print Memory: 10MB
- Print Language: SPL
- Path Type: C-Path
- Cassette Capa.: 150sheets
- Outlet Stacking Capa.: 50sheets
- Toner Cartridge: initial(1K), sales(3K)
- ADF Capacity: 30sheets
- Scan Method: 600 dpi Color CIS
- Copy Speed: SDMC: 22Cpm/Ltr,
SCX-4521F Series
- Interface: USB1.1, IEEE1284
MDMC: 7Cpm/Ltr
ELECTRONICS
* This service manual is a property of Samsung Electronics Co., Ltd.
Any unauthorized use of Manual can be punished under applicable
international and/or domestic law.
* This service manual is also provided on the web, the ITSELF
system Samsung Electronics Co., Ltd.
http://itself.sec.samsung.co.kr
Samsung Electronics Co.,Ltd. Aug. 2005
Printed in Korea.
VERSION NO. : 1.00 CODE : JC-0139H
Contents
1. Precautions
1.1 Safety Warning 1-1
1.2 Safety Caution 1-2
1.3 ESD Precautions 1-4
2. Product Specification
2.1 Product Overview 2-1
2.2 Specifications 2-1
2.3 Model Comparison Table 2-5
3. System Overview
3.1 System Outline 3-1
3.2 H/W Structure and Descriptions 3-7
3.3 S/W Structure and Descriptions 3-19
3.4 Initial Product Installation 3-24
4. Alignment and Adjustments
4.1 Sample Pattern 4-1
4.2 Control Panel 4-2
4.3 Consumables and Replacement Parts 4-4
4.4 LED Status Error Messages 4-4
4.5 Periodic Defective Image 4-5
4.6 How to use DCU 4-6
4.7 Paper Path 4-11
Continued
5. Disassembly and Reassembly
5.1 General Precautions on Disassembly 5-1
5.2 Disassembly and Reassembly 5-2
6. Troubleshooting
6.1 Checking Symptoms 6-1
6.2 Bad discharge 6-4
6.3 Malfunction 6-8
6.4 Bad software environment 6-13
6.5 Bad Image 6-17
7. Exploded Views & Parts List
7.1 Exploded Views and Parts List 7-1
8. Block diagram
8.1 System Block Diagram 8-1
8.2 System Timing Chart 8-2
9. Connection Diagram
9.1 Connection Diagram 9-1
10. Schematic Diagram
10.1 Main Board 10-1
10.2 Connector Circuit Diagram 10-5
10.3 SMPS Circuit Diagram 10-6
10.4 HVPS Circuit Diagram 10-7
Continued
11. Reference Information
11.1 Troubleshooting Tools 11-1
11.2 Acronyms and Abbreviations 11-2
11.3 Selecting printer locations 11-4
11.4 Sample Tests Patterns 11-5
12. Circuit Description
12.1 Engine Controller 12-1
Precautions
Samsung Electronics
Service Manual
1-1
1
1
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, NR
SIKKERHEDSBRYDERE ER UDE AF FUNKTION.
UNDG UDSAETTELSE FOR STR LNING.
ADVARSEL. - USYNLIG LASERSTR LNING N R DEKSEL
PNES. STIRR IKKE INN I STR LEN.
UNNG EKSPONERING FOR STR LEN.
VARNING - OSYNLIG LASERSTR LNING N R DENNA DEL
R PPNAD OCH SP RREN R URKOPPLAD.
BETRAKTA EJ STR LEN. STR LEN R FARLIG.
VARO! - AVATTAESSA JA SUOJALUKITUS OHITETTAESSA
OLET ALTTIINA N KYM TT M LLE LASERS TEILYLLE L KATSO STEESEEN.
Samsung Electronics
Service Manual
Precautions
1-2
1.2 Caution for safety
1.2.1 Toxic material
This product contains toxic materials that could cause illness if ingested.
(1) If the LCD control panel is damaged it is possible for the liquid inside to leak. This liquid is toxic. Contact with the skin
should be avoided, wash any splashes from eyes or skin immediately and contact your doctor. If the liquid gets into
the mouth or is swallowed see a doctor immediately.
(2) Please keep toner cartridges away from children. The toner powder contained in the toner cartridge may be harmful
and if swallowed you should contact a doctor.
1.2.2 Electric Shock and Fire Safety Precautions
Failure to follow the following instructions could cause electric shock or potentially cause a fire.
(1) Use only the correct voltage, failure to do so could damage the printer and potentially cause a fire or electric
shock.
(2) Use only the power cable supplied with the printer. Use of an incorrectly specified cable could cause the cable
to overheat and potentially cause a fire.
(3) Do not overload the power socket, this could lead to overheating of the cables inside the wall and could lead to
a fire.
(4) Do not allow water or other liquids to spill into the printer, this can cause electric shock. Do not allow paper
clips, pins or other foreign objects to fall into the printer these could cause a short circuit leading to an electric
shock or fire hazard..
(5) Never touch the plugs on either end of the power cable with wet hands, this can cause electric shock. When
servicing the printer remove the power plug from the wall socket.
(6) Use caution when inserting or removing the power connector. The power connector must be inserted com-
pletely otherwise a poor contact could cause overheating possibly leading to a fire. When removing the power
connector grip it firmly and pull.
(7) Take care of the power cable. Do not allow it to become twisted, bent sharply round corners or 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.
Precautions
Samsung Electronics
Service Manual
1-3
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
Precautions
1-4
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 10.4kg 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 10.4Kg, 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.
Precautions
Samsung Electronics
Service Manual
1-5
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.
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.
1.4 Super Capacitor or Lithium Battery Precautions
Product Specifications
Samsung Electronics
Service Manual
2-1
2
2
Item Descriptions Remark
Basic Model SCX-4521F(4-in-1 Flatbed MFP)
SCX-4321(3-in-1 Flatbed MFP)
Target User SOHO, Economical(Speed/Price) Customer
Customer Benefits - Compact Size
(Sales Points) - 22ppm/A4, 22ppm/Letter fastest speed in its price class
- Favorite Copy
- ID Card Copy
- Toner Save
Key Specification - up to 22ppm/A4(Up to 22ppm/Letter)
- 150 sheets Multi-Purpose type paper input/50 sheets Paper Output
- 3,000pages toner capacity
- 600dpi Print/Copy Resoulusion
- Samsung Print Language
- 16MB System memory
- 30 ADF
- 33.6 Kbps Fax Modem
- 100 Speed Dial
- 72 Hour Battery Back-up
2. Product Specifications
2.1 Product Overview
Samsung Electronics
Service Manual
Product Specifications
2-2
2.2 Specifications
Product Specifications are subject to change without notice. See below for product specifications.
2.2.1 General Specifications
Item Descriptions (SCX-4321 / SCX-4521F)
Major Features Copier, Print, Scan, Fax(SCX-4521F)
Net Dimension (WxDxH) 438(W)*374(D)*368(H)(17.2x14.7x14.5")
Net Weight(Inc. Toner Cartridge) 10.4kg
CPU Chorus-2 (66MHz)
LCD 2 Line x 16 characters / 2Line x 8 characters(for china and korea)
Toner Save Yes (With toner save button)
I/O Interface USB1.1 (Compatible with USB 2.0), IEEE 1284 Parallel
Network Interface No
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, 4.5A
220 ~ 240 VAC, 50/60 Hz, 2.5A
Power Consumption Sleep Mode : Under 10 W
Standby Mode : 65W
Average : 350 W (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 35 seconds
from Sleep Mode Less than 30 seconds
(Recovery time)
Max. Monthly Print 4,200 pages
Volume Scan ADF: 2,500 pages, PLATEN: 1,700 pages
Average Monthly Print Volume 400 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 16MB
Page Counter Yes
Print Configuration Sheet(System Data) Yes
Items SCX-4321 SCX-4521F
Method Laser Beam Printing Laser Beam Printing
Speed Up to
22ppm
in A4 (
22ppm
in Letter) Up to
22ppm
in A4 (
22ppm
in Letter)
Emulation SPL SPL
Power Save Yes
(Interval option: 5, 10,15, 30, 45 minute)
Yes
(Interval option: 5, 10,15, 30, 45 minute)
Resolution Normal 600 x 600 dpi 600 x 600 dpi
RET - Memory 10MB 10MB
First Print Out From Stand by Approx. 11 seconds Approx. 11 seconds
Time From Cold Status Less than 41 seconds Less than 41 seconds
Duplex Print - WHQL Compliant Window XP Window XP
Printable Area A4: 201.6x288.6mm A4: 201.6x288.6mm
LTR: 207.6x270.6mm LTR: 207.6x270.6mm
Legal: 207.6x347.6mm Legal: 207.6x347.6mm
Folio: 207.6x322.6mm Folio: 207.6x322.6mm
Halftone (Gray Scale) 256 levels 256 levels
Product Specifications
Samsung Electronics
Service Manual
2-3
2.2.2 Print Specifications
Items SCX-4321 SCX-4521F
Compatibility
Twain standard / WIA Standard (Window 2000/XP) Twain standard / WIA Standard (Window 2000/XP)
Scan Method
600dpi Color CIS(Contact Image Sensor) 600dpi Color CIS(Contact Image Sensor)
Module Module
PC Scan Speed Lineart, Halftone 10sec Platen(13sec ADF) 10sec Platen(13sec ADF)
through Platen Gray 23sec Platen (26sec ADF) 23sec Platen (26sec ADF)
Color 300dpi 65sec Platen(70sec ADF) 65sec Platen(70sec ADF)
Resolution Optical 600 x 600 dpi 600 x 600 dpi
Enhanced 4800 x 4800 dpi 4800 x 4800 dpi
Halftone 256 levels 256 levels
Scan Size Max. Document Width Max.216mm (8.5") Max.216mm (8.5")
Effective Scan Length 297 mm (11.7") 297 mm (11.7")
Effective Scan Width Letter/Legal: 208mm(8.2")A4: 202mm Letter/Legal: 208mm(8.2")A4: 202mm
Scan-to Button Yes Yes
Application Yes Yes
Scan Depth Color 24 bit 24 bit
Mono
1bit for Line art, Halftone, 8 Bit for Gray scale 1bit for Line art, Halftone, 8 Bit for Gray scale
2.2.3 Scan Specifications
Samsung Electronics
Service Manual
Product Specifications
2-4
2.2.4 Copy Specifications
Item Descriptions (SCX-4321 / SCX-4521F)
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 4(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)
Items SCX-4321 SCX-4521F
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 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)
2.2.5 T elephone Specificationc
Product Specifications
Samsung Electronics
Service Manual
2-5
2.2.6 Fax Specifications
Items SCX-4321 SCX-4521F
Compatibility - ITU-T G3
Modem Speed - 33.6Kbps
TX Speed - 3sec
Compression - MH/MR/MMR/JPEG
Color Fax - Yes(Tx Only)
ECM - Yes
Resolution Std - 203*98dpi
Fine - 203*196dpi
S.Fine - 300*300dpi
Photo - 203*196dpi
Color - 200*200dpi
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
Samsung Electronics
Service Manual
Product Specifications
2-6
Items SCX-4321 SCX-4521F
Input Capacity and Types 150-sheet Cassette Tray (75 g/ , 20 lbs) 150-sheet Cassette Tray (75 g/ , 20 lbs)
Output Capacity and Types 50-sheet Face Down(75 g/
, 20 lbs) 50-sheet Face Down(75 g/ , 20 lbs)
Manual Tray 1 sheet 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/ ) for 150 sheets, Cassette Tray
16~43lb (60 to 165g/
) for 1 sheet, Manual Tray
ADF Capacity Up to 30 sheets of 20lb(75g/
) paper Up to 30 sheets of 20lb(75g/ ) paper
ADF Document Size Up to Legal Up to Legal
2.2.7 Paper Handling Specifications
2.2.8 Software
Items SCX-4321 SCX-4521F
Compatibility DOS No No
Win 3.x No No
Win 95 No No
Win 98/ME Yes Yes
Win NT 4.0 Yes Yes
Win 2000 Yes Yes
Win XP Yes Yes
Mac Yes (10.3 ) Yes (10.3 )
Linux Yes Yes
Driver Printer SPL SPL
TWAIN Yes Yes
WIA Yes Yes
ScanToPC Yes Yes
PC-FAX No Yes (Send only)
Application RCP Yes Yes
Status monitor No No
SmarThru4 Yes Yes
Product Specifications
Samsung Electronics
Service Manual
2-7
2.2.9 Accessory
Items SCX-4321 SCX-4521F
Quick Setup Guide Yes (include Setup Guide and Function Guide)
Quick User Guide Yes (Korea Only) Yes (Korea Only)
S/W CD ROM
1 CD (Contents; Electronic User Manual, SmarThru, Print Driver, Twain Driver, RCP)
Toner Cartridge 1 EA
Power Cable 1 EA
Telephone Jack No 1 EA
Printer Cable No No
Tray Coner Yes Yes
2.2.10 Consumables
Items SCX-4321 SCX-4521F
Type Single Cartridge Single Cartridge
How to install Front door open and front loading Front door open and front loading
Toner Yield
3,000 pages at ISO 19752 Std. Coverage(Ships with 1,000 pages Starter Toner Cartridge)
Code SCX-4521D3 SCX-4521D3
Level Sensor - -
System Overview
Samsung Electronics
Service Manual
3-1
3
3
3. System Overview
3.1 System Layout
The SCX-4521F/4321 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 chorus2
CPU(ASIC) and 1 Board. Scanner part is composed of ADF and Platen and is connected with Main by
Harness.
ADF ROLLER
Scanner part
Engine Part
ADF-UPPER
PICK-UP ROLLER
EXIT ROLER
WHITE BAR
ADF-GLASS
FEED ROLLER
SCAN UPPERSCAN UPPERSCAN UPPER
ADF-LOWER
COVER OPEN
BIN PATH
Samsung Electronics
Service Manual
System Overview
3-2
3.1.1 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
3.1.2 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)
3.1.3 Driver Ass’y
- Gear driven power unit. The motor supplies power to the paper feed unit, the fuser unit, and the toner
cartridge.
3.1.4 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.
3.1.4.1 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.
3.1.4.2 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.
3.1.4.3 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.
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3-3
3.1.4.4 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.
3.1.4.5 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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STACKER
COVER-M-SIDE R
EXTEND-SMALL
EXTEND-LARGE
TRAY CASSETTE
COVER-M_DEVE
FIXING BKT
SPEKER
COVER-M-SIDE-L
COVER-M_REAR
COVER-M_JAM
COVER-M_MIDDLE
SCAN
UPPER
MOTOR
ASS’Y
SCAN
LOWER
TIMING
BELT
CIS
SLIDER
-CIS
ADF
GLASS
SCAN
GLASS
KEY & OPE
COVER
[Case part figure]
[Scan part figure]
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3.2 Engine H/W Specification
1) Recording Method : LSU(Laser Scanning Unit)
2) Printing Speed : 20ppm
(In continuing printing base Letter, printing pages from 2nd to last during 1min)
3) Recording Density : 600 dpi
4) Cassette Capa. : Cassette ; 150sheets(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 19752 Standard Pattern Printing)
9) First Print Out Time : within 11sec ( Standby )
10) Warming up time : within 35sec (Ambient : 25 °C)
3.2.1 Main Board Control Part
Main control part of SCX-4521F 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 : Chorus2 is the main CPU and is made up on the 16/32bit RISC architecture using ARM7TDMI
core. Main CPU controls the whole system according to the program code which stored in the
Flash-ROM memory.
- Summary of the Key Function Block:
1.8V for internal Core, 3.3V for I/O Pad with 4KByte Cache.
Image Processor included.
On-Chip clock generator with PLL.
Memory and External Bank Control.
DMA Control (5-Channel)
Interrupt Control.
2-port USB Host/1-port USB device(ver 1.1) interface control.
Parallel interface control.
UART(2-Channel)
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Synchronous Serial Interface Control.
A/D Converter(10-bit, 2channel).
General I/O Port control.
Tone Generator.
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 : 2 Mbyte
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 : 16 Mbyte
Access Time : 66MHz based on system bus clock.
Data Backup : 72 Hours
Backup Battery Charging Time : 100hours when completely discharged.
3.2.2 Scan 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
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3) CIS Driving Part
- 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
3.2.3 Fax Modem Part
1) Modem Part
The modem part is consist of FM336(FAX Modem chip), LIU(Line Interface Unit) and modem analog front
end(AFE) functional part.
- The feature of the FM336 modem chip is as below;
Communication Mode : Half Duplex
Modem Method
GROUP 3 : ITU-T V34, V17, V29, V27ter
Tonal Signal : ITU-T T.30
Binary Signal : ITU-T V.21, T.30
Image Transmission Time : 3sec ( ITU-T NO.1 CHART/Memory Tx/ECM )
Data Compress : MH, MR, MMR, JPEG
Modem Speed : 33600 / 28800 / 14400 / 12000 / 9600 / 7200 / 4800 / 2400 bps
Receive Level : 0 ~ -48dBm
Output Level
Adjustable : -6 ~ -15dBm ( 1dBm Step )
Initial Setting : -12dBm
Receive dynamic range:
0 dBmto-43 dBmfor V.17,V.29,V.27 ter and V.21
-9 dBm to -43 dBm for V.34 halfduplex
2) The Gain of the Line signal can be adjusted by setting the register value of the FAX modem chip ,Tx and Rx path
is almost directly connected to the impedance matching transformer of the LIU.
- Adjust Tx Level within Setting Level+0,-2dB range.
- Adjust Rx Level that has the same level as the TIMS out level if possible, and must not exceed the TIMS
out level.
3) Speaker Driving Part
Analog Switch(MC14053BD) makes a path for FAX Tone, Ring, Key click sound and Analog MUX
(MC14051) makes a different signal level so that the the Speaker driver chip(MC34119) can driving the
Speaker with different sound volume.
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3.2.4 Printing Process 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.
3.2.5 Line Interface Part
Line interface part helps the machine connect to the PSTN or PABX Line and is made of almost primary circuit.
Its main function is Line connection, Line state monitoring and TAD interface that enables a extension telephone or
TAD machine to connect to the SCX-4521F machine.
3.2.6 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
OPC Drum
Photo Diode
LD Driver circit
Protector panel
LD(Laser Diode)
Polygon Mirror
Polygon Motor
Motor Driver
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3.3 Deverope Process
- Developing Method : Non magnetic 1 element contacting method
- Toner : Non magnetic 1 element shatter type toner
- Toner Qty:35gf /60gf (1k/3k)
- The life span of toner 1k/3k sheets (ISO 19752 Standard Coverage )
- Toner Residual Sensor : None
- OPC Cleaning : Use the conventional cleaning blade
- Handling of wasted toner : Discard by collecting waste-toner at waste-toner bin.
- OPC Drum Protecting Shutter : None
- Classifying device for toner cartridge: ID is classified by interruption of the frame channel.
- Development Roller type : conductive elastic roller
- Doctor BLADE Type : Regulating toner layer by pressure
- Charge Roller Type : Conductive Roller Contact-Charge
3.3.1 Fuser Specification
1) Heat Lamp
- Heat Lamp Terminal Shape : Terminal Single Type
- Voltage 120 V : 115 5 %, 220 V : 230 5 %
- Capacity : 600 Watt 30 W
- Light Qty Distribution : 140%
- Life : 3000 Hr
2) Thermostat
- Thermostat Type : Non-Contact type THERMOSTAT
- Control Temperature : 150°C 5°C
3) Thermistor
- Thermistor Type : HF-R0060 (SEMITEC 364FL Type)
- Temperature Resistance : 7 k (180 °C)
- SYSTEM Temperature SETTING
Stand by : 165 5°C
Printing : 175 5°C(5 minutes before)
170°C
5°C(5 minutes after)
Overshoot: 200°C or less
Overheat :210°C or less
4) Safety Relevant Facts
- Protecting device when overheating
1st protecting device : H/W cuts off when detecting an overheating
2st protecting device : S/W cuts off when detecting overheating
3st protecting device : Thermostat cuts off the power
- Safety device
The power of Fuser is cut-off after front cover is open.
The overheating safety device for customer
The surface temperature of the Fuser Cover is under 80°C
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3.4 Sanner Part
600dpi Color CIS Module for Flat bed, SCX-4521F uses the CIS scanning method
1) CIS SPEC
- Scanning size : 216 mm ( width for letter-size)
- Light source : LED
- Scanning sensor: CIS 600/300 dpi
- Scanning mode : Color SCAN / Mono SCAN
- MTF : 30% (300 dpi Chart)
- CIS interface : Analog output
- Power supply : 3.3V
- Clock Frequency: 5MHz max.
- Number of output : 1
- LED Current : Red/Green/Blue : 60mA
- Clamp Level : 1.1V
- Connection : 12 pin FFC connector (pitch 1.0mm)
2) Scan Resolution
(a) Transmission
- Normal : Vertial: 3.85 Line/mm, Horizontal: 8 Pels/mm :203 x 98dpi
- Fine : Vertial: 7.7 Line/mm, Horizontal: 8 Pels/mm :203 x 196dpi
- Super Fine : Vertial: 11.8 Line/mm, Horizontal: 11.8 Pels/mm ;300 x 300dpi
(b) When Copy : Vertial: 11.8 Line/mm, Horizontal: 23.6 Pels/mm :600x300dpi(ADF)
Vertial: 23.6 Line/mm, Horizontal: 23.6 Pels/mm :600x600dpi(Platen)
3) Half Tone (Gray Scale) : 256 Levels
4) Scan Line Time
(a) Tx
- Normal : 1.5 ms/Line
- Fine : 1.5 ms/Line
- Super Fine : 1.5 ms/Line
(b) Copy : 1.5 ms/Line
(c) Scan
- Color : 4.5msec/line
- Gray : 4.5msec/line
- Mono : 4.5msec/line
5) Scanning Width
- MAX SCAN WIDTH : 216 mm (8.5 inches)
- Effective Scan Width: 208mm
6) ADF Motor
(a) Motor Spec
- : 24VDC
- : 0.6A(Peak)
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7) Motor Driver speed & method
(a) FAX Transmission
- Normal Mode : 2000 pps
- Fine Mode : 1000 pps
- Super Fine Mode : 667 pps
(b) Copy Job : 667 pps, 2-2
- max(30sheets) : 50gf
- min(1sheets) : 20gf
8) Document Detect sensor
(a) Type : Photo interrupt
(b) Position : ADF PBA
(c) LED - max current : 50mA
- max voltage : 3.3V
(d) Output - Logic "H" : No Paper
- Logic "L" : Paper
(e) Lever-Sensor DOC : ADF Lower Torsion Spring
9) Regi Detect sensor
(a) Type : Photo interrupt
(b) Position : ADF PBA
(c) LED - max current : 50mA
- max voltage : 3.3V
(d) Output - Logic "H" : No Paper
- Logic "L" : Paper
(e) Lever-Sensor DOC : ADF Lower Torsion Spring
10) Document Scan sensor
(a) Type : Photo interrupt
(b) Position : ADF PBA
(c) LED : - Max current : 50mA
- Max Voltage : 3.3V
(d) Output - Logic "H" : Off(No Position), No Paper
- Logic "L" : On (Doc Position), Paper
(e) LEVER - SENSOR SCAN : Scan Lower Torsion Spring
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3.5 OPE(Operational Panel Equipment)
1) Ope Panel
OPE Panel has a MICOM Chip on it and communicates with Main CPU using Serial communication
Line(SIO). OPE Panel consists of Micom, Key Matrix Part, LED Driving Part and LCD Part.
2) Key Description
3) LCD Part
- Number of Characters : 16 Characters x 2 line
Clock, Date display
System Status display
Alarm, Error Message display
Function Dialog Message display
No Part Feature Function
1 Common 3*4Key Dialing and Option Input
Start Starting Fax/Copy Job
Stop/Clear Cancel Current Job/Return to default
Menu Option select
Upper Level Return to upper level menu
Enter Option select/Execute
Next menu or Next option item
Previous menu or Previous option item
2 Save Toner Save TONER SAVE MODE select
3 Copy Reduce/Enlarge Select ZOOM ratio when copy
No.of Copies Select the number of copies
Original Type Change Copy Modes(Text,Text/Photo,Photo)
Darkness
Change the Darkness of the Copied image (Light/Normal/Dark)
Favorite Copy Select one of the predefined Copy templates.
4 Fax Resolution STANDARD>FINE>SUPER
FINE>PHOTO>COLOR
Phone Book Search the user defined Phone number.
Broadcasting When sending FAX data to many place in the same time.
On Hook Dial On Hook Dial
Redial / Pause Last number Redial / Pause
5 Scan Scan to select [scan to PC], [scan to FAX], [scan to E-mail] function.
U1
U3
12.0MHz
U8
U9
U12
U10
U7
U5
(IC-DRAM/
512K x 16Bit)
(IC-POSI, ADSUST REG)
(IC-CMOS LOGIC, INVER TER)
(IC-MOTOR DRIVER)
(IC-VOLTAGE COMP)
(IC-CLOCK GENERATOR)
(IC-EEPROM/256x12Bit)
(IC-POSI, FLXED REG)
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3.6 SMPS & HVPS
It is the power source of entire system. It is assembled by an independent module, so it is possible to use for
common use. It is mounted at back of the machine. Power part is divided by two independent PBAs - SMPS PBA
and HVPS PBA. SMPS PBA supplies the DC power for driving the system and supplies the AC power to the fuser.
SMPS has two output channels : +5V and +24V. HVPS PBA supplies High voltage to the developer part to make a
printing image on the paper. High voltages applied to the MHV, THV, DEV, SUPPLY.
3.6.1 SMPS
1) AC Input
- Input Rated Voltage : AC 220V ~ 240V / AC 110V ~ 127V
- Input Voltage fluctuating range: AC 180V ~ 270V / AC 100V ~ 135V
- Rated Frequency : 50/60 Hz
- Frequency fluctuating range : 47 ~ 63 Hz
- Input Current : Under 4.0Arms / 2.5Arms
(But, the status when lamp is off or rated voltage is inputted/outputted )
2) Rated Output Power
3) Consumption Power
NO Items CH1 CH2 Remarks
1 CHANNEL +5V +24.0V
2 CONNECTOR PIN CON 2 CON 2 Jam cover switch
5V PIN : #5pin 24V PIN: #2, #3, #4 included
GND PIN: #6pin GND PIN: #7pin
3 Rated Output +5V ± 5%(4.75 ~ 5.25V)
+24V -10%/+15%(21.6V ~ 27.6V)
4 Max. Output current 0.8 A 2.5 A
5 Peak Loading current 1.0 A 2.7 A
within 1ms Duration
6 RIPPLE NOISE Voltage 100mVp-p or less 500mVp-p or less
7 Maximum output 2.5W 36W
8 Peak output 4W 55.2W 1ms
9 Protection for loading Fuse Protection or Shutdown Fuse Protection or Shutdown
shortage and within 1.5A ~ 3.0A range. within 3.5A ~ 4.5A range.
overflowing current
NO Item CH1(+5V) CH2(24V) System
1 Stand-By 0.6 A 1.3 A AVG : 65Wh
2 Printing 0.8 A 1.9 A AVG : 350Wh
3 Sleep-Mode 0.5 A 0.3 A AVG : 10Wh
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