SAMSUNG ML5100AXEU Service Manual

LASER PRINTER

ML-5100A

SERVICE Manual

LASER PRINTER

CONTENTS

1. Precautions

2. Specifications

3. Disassembly and Reassembly

4. Troubleshooting

5. Exploded Views and Parts List

6. Electrical Parts List

7. Schematic Diagrams

ELECTRONICS

P/N. JC68-00073A Rev. 1.00

1. Precautions

1-1 Safety Precautions

Read each caution carefully:

1.Do not use this printer near water or when exposed to inclement weather.

2.Do not place this printer on an unstable cart, stand or table; the product may fall, causing serious damage to the product.

3.Slots and openings in the cabinet are provided for ventilation. To ensure reliable operation and to protect the printer from everheating, do not block or cover any of these openings. Do not place the printer in an enclosure unless the enclosure provides adequate ventilation.

4.Never push objects of any kind into the printer through the cabinet ventilation slots as they may touch dangerous high voltage points, create short circuits, cause a fire, or produce an electrical shock. Never spill liquid of any kind on the printer.

5.Do not place the printer in a location where someone may trip on the cords.

6.Select a work surface that is large enough to hold the printer.

7.Position the printer within six feet of the computer and within five feet of an electrical outlet.

8.Operate this printer using the power source (110V, 220V, etc) indicated on the marking label. If you are not sure of the type of power source available, consult your dealer or local power company.

9.If you need to use an extension power cord with this printer, make sure that it uses a three-wire grounded cord and that the total ampere ratings for all of the products using the extension do not exceed the extension cord ampere rating. Also, make sure that the total of all products plugged into the wall outlet does not exceed 15 amperes.

10.Do not allow anything to rest on the power cord or data communications cable.

11.Unplug this printer from the wall outlet before cleaning. Do not use liquid cleaners or aerosol sprays. Use a damp cloth for cleaning.

12.Do not touch the surface of the photo-sensitive drum as marks or scratches may impair print quality.

13.Do not expose the drum unit to direct light for prolonged periods.

14.Use only standard papers, OHP films, and approved envelopes. Feed OHP films though the manual feed slot only. See specifications for approved papers and envelopes.

15.Other than replacing consumables such as paper and toner, refer all questions to qualified service personnel.

WARNING :

NEVER OPERATE AND SERVICE THE PRINTER WITH THE PROTECTIVE COVER REMOVED FROM LASER/SCANNER ASSEMBLY. THE REFLECTIVE BEAM, ALTHOUGH INVISIBLE, CAN DAMAGE YOUR EYES.

Samsung Electronics

1-1

Precautions

1-2 Servicing Precautions

Note :

Requirements for AC power are described on the label affixed to the rear of the printer. Check the AC voltage rating requirement before use.

1.Before disassembly, pull the power plug from the AC power connector.

2.To avoid spilling toner inside the machine, do not turn the printer over or on its side before removing the developer cartridge.

3.Faulty installation of DRAMs may cause permanent damage to the Laser Printer.

4.Use only+5V power for video controller-related circuitry.

5.When replacing parts, use only the same type of part as the original. Replacing components with a second vendor’s part may cause faulty operation.

6.Check the insulation between the blades of the AC plug and accessible conductive parts (examples : metal panels and input ports).

7.Insulation Checking Procedure:

Disconnect the power cord from the AC power source. Connect an insulation resistance meter (500V) to the blades of the AC plug.

The insulation resistance between each blade of the AC plug and accessible conductive parts (see left) should be greater than 1 megaohm.

8.Never defeat any of the B+ voltage interlocks. Do not apply AC power to the unit (or any of its assemblies) unless all solid-state heat sinks are correctly installed.

9.Always connect a test instrument’s ground lead to the instrument chassis ground before connecting the positive lead; always remove the instrument’s ground lead last.

1-3 ESD Precautions

Some semiconductor (“solid state”) devices are easily damaged from static electricity. Such components commonly are called Electrostatically Sensitive Devices (ESDs); examples include integrated circuits (ICs), Large-Scale Integrated circuits (LSIs), some field-effect transistors, and semiconductor chip components. The following techniques will reduce the occurrence of component damage caused by static electricity:

CAUTION : Be sure the power is off to the chassis or circuit board, and observe all other safety precautions

1.Immediately before handling any semiconductor components assemblies, drain the electrostatic charge from your body by touching a known earth ground. Alternatively, wear a discharging wrist strap device. (Be sure to remove the strap before applying power to the unit under test to avoid potential shock.)

2.After removing ESD-equipped assembly, place it on a conductive surface such as aluminum foil to prevent accumulation of an electrostatic charge.

3.Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ESDs.

4.Use only a ground-tip soldering iron when soldering or desoldering ESDs.

5.Use only anti-static solder removal device. Some solder removal devices are not rated as “antistatic;”these can accumulate sufficient electrical charge to damage ESDs.

6.Do not remove a replacement ESD from its protective package until you are ready to install it. Most replacement ESDs are package with leads that are electrically shorted together by conductive foam, aluminum foil or other conductive materials.

7.Immediately before removing the protective 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.Minimize body motions when handling unpackaged replacement ESDs. Motion such as your clothes brushing together, or lifting a foot from a carpeted floor can generate enough static electricity to damage an ESC.

9.Handle ICs and EPROMs carefully to avoid bending a pin.

10.Pay attention to the direction of parts when mounting or inserting them on a PCB.

11.Components can be permanently damaged if heated for longer than necessary while welding. All components are susceptible to heat damage.

1-2	Samsung Electronics

2. Specifications

2-1 General

Emulation	PCL5e,PCL6
Interface	Centronics IEEEP1284 compatible bi-directional (Nibble, Byte, ECP)
	USB (Universal Serial Bus)
Print Speed	8 PPM (A4 Size, 5 % Character Pattern)
Print Method	Non-impact Electrophotography, Laser Beam
Resolution	600 X 600 DPI
Memory	Standard: 4 Mb
	Expandable up to 36 Mb
Operating Environment	Temperature : 5 ~ 32.5 oC,
	Humidity: 20 ~ 85 % RH
Storage Environment	Temperature : -20 ~ 40 oC,
	Humidity: 10 ~ 95 % RH
Weight	Net : 7.5 kg (max.),
	Gross : 10 kg (max.)
Dimension	345 (W) X 365 (D) x 224 (H) mm
Certification & Compliance	CE, TUV, SEMKO, NEMKO, DEMKO, C-tick
	FCC, UL, CSA, CDRH, CB, EPA

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2-1

Specifications

2-2 Electrical

Input Voltage	USA : AC 100~127 V , 50/60 Hz ± 3 Hz (Normal : 115V)
	EUROPE : AC 200~240 V , 50/60 Hz ± 3 Hz (Normal : 230V)
DC Output Voltage
Line Regulation	24 V ± 3 %
	5 V ± 2 %
Load Regulation	24 V - 3 %/+10 %
	5 V ± 3 %
Ripple Noise	24 V : 120 mV (Peak 400 mV)
	5 V : 50 mV (Peak 100 mV)
Over Current Protect	24 V :	2.7 A ± 10 %		(by C't )
	5 V :	1.5 A ± 10 %		(by C't )
Power Consumption	Max. 450 W		Everage: 200 W
	Power Save Mode: Less than 15W
Warming Up Time	20 seconds or less
First Print Time	Idle mode : 17 seconds or less
	Power Save mode : 30 seconds or less
Acoustic Noise	Standby : 33 dB or less
	Sleep Mode: Background level
	Operating : 50 dB or less
Reliability
Insulation Resistance	10 Mohm or less (at DC 500 V)
Dielectric Strength	AC 1500 V (DC 2100 V), 10 mA
Ground Continuous	0.1 ohm or less
Voltage DIP	Rated voltage ± 15 %
AC Impulse Noise	AC 1000 V 10, 100, 200, 400, 1000 ns
Leakage Current	3.5 mA or less
Surge	0.5 ~ 4 kV,		0.25 ~ 2 kA
Ozone Emission	0.1 ppm or less (8 hours)
Top Cover Open	Isolating the input power of the LSU, high voltage part, and fuser
Overcurrent Protect	Fuse inside the Engine Controller
Fusing System
Trouble Sensing	The temperature doesn't rise to the specific temperature within a
	specific time. Fuser error occurs if the temperature is too high.
Overheat Sensing	240 ~ 250 oC		(The thermostat cuts off the Fuser from the power.)
Thermistor Open Sensing	Without the initial temperature change of the Fuser
Source of Light	Laser Diode (LSU)
Developer
Developing	Non-magnetic contact developing
Charging	Conductive roller charging
Density Adjustment	Dark, Medium
Transfer System	Pre-transfer by LED & conductive roller
Fusing System	Temperature & Pressure
Ozone Emission	0.02 PPM or less (8 hours)

2-2	Samsung Electronics

Specifications

2-3 Print Quality

Conditions
Paper	Normal paper (75 g/m2)
Environment	Temperature : 20 ~ 25 oC, Humidity : 40 ~ 60 % RH
Print Quality
Image Density	min. 1.3
Background	max. 1.0
Uniformity	max. 0.2 (including continuous print)
Fusing	min. 80 % (all black)
Start Position	Top : x ± 3 mm, Side : y ± 3 mm (from left)
Skew	Top : max. ± 1.5 mm/200 mm
	Side : max. ± 1.5 mm/250 mm
Orthogonality	± 1.0 mm
Horizontal Scan	± 0.5 mm/208 mm
	(Bowed Line Skew : S600,0909 pattern)
Special Paper Exception	Image Density : min. 1.0 (envelope)
	Fusing : min. 70 %	(all black, envelope/OHP/postcard)
Paper Jam	1/2,000 or less
Paper Curl	First : 16 mm or less	(10 sheets)
	After Cooling: 12 mm or less (10 sheets)

2-4 Option

Toner Cartridge
Type	One-cartridge type
Life Span	Built-in toner cartridge : 5,000 pages at 5 % coverage
	Optional toner cartridge: 5,000 pages at 5 % coverage
	Note: Its duration may last longer under Econo mode.
Memory (ML-5100A only)	Memory RAM: 4,8, 16, 32 Mb (memory is expandable to 36 Mb)

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2-3

Specifications

2-5 Paper

Input Paper Size

Paper Type	Size	Feeding Source
A4	210 x 297 mm	Paper Tray or Manual feeder
Letter	216 x 279 mm	Paper Tray or Manual feeder
B5 (ISO)	176 x 250 mm	Paper Tray or Manual feeder
Executive	184 x 267 mm	Paper Tray or Manual feeder
Folio	216 x 330 mm	Paper Tray or Manual feeder
Legal	216 x 356 mm	Paper Tray or Manual feeder
Com-10 Envelope	105 x 241 mm	Manual feeder only
Monarch Envelope	98 x 191 mm	Manual feeder only
DL Envelope	110 x 220 mm	Manual feeder only
C5 Envelope	162 x 229 mm	Manual feeder only
C6 Envelope	114 x 162 mm	Manual feeder only
A5 Envelope	148 x 210 mm	Manual feeder only
Transparency	A4 or Letter	Manual feeder only
Label paper	A4 or Letter	Manual feeder only
*Others	Width: 75-216 mm, Length: 125-356 mm	Paper Tray or Manual feeder

Feeding Source	Paper tray and manual feeder
Paper Weight	60 ~ 163 g/m2 (16 ~ 28) , Cardstock/other : 24 ~ 43 lb
Input Paper Capacity	Paper tray:	150 sheets,	Manual feeder : 1 sheet at a time
Paper Stacker Capacity	Face down :	100 sheets,	Face up : 1 sheet
Paper Limitations	-Adhesive label sheets specifically designed for laser printers
	-Transparencies specifically designed for laser printers
	-Envelopes with peel-off adhesive strips or more than one fold-over flap
	to seal must have adhesive compatible with the heat and pressure of the
	printer’s fusing process.
Unacceptable Papers	-Paper with embossed lettering, perforations, or rough texture
	-Paper with which color was added after the paper was made
	-Paper forms whose ink is not for laser printing

2-4	Samsung Electronics

3. Disassembly and Reassembly

3-1 Removal Procedures

Cautions:

•Be sure to unplug the power cord whenever you are working on the printer with one of the covers removed.

•Be sure to remove the toner cartridge before you repair parts.

Releasing Plastic Latches

Many of the parts are held in places with plastic latches. The latches break easily; release them carefully. To remove such parts, press the hook end of the latch away from the part to which it is latched.

3-2 Face-Up Cover and Front Cover

1.Place your fingers on both sides of the face-up cover, push the cover, and pull it down.

2.Bend the cover slightly to release the tabs at the end, then remove the cover.

Samsung Electronics

3-1

Disassembly and Reassembly

3. Open the front cover with hand.

4.Remove a screw securing the front cover to the main frame.

5.Unlatch the front cover, then remove the front cover.

3-2	Samsung Electronics

Disassembly and Reassembly

3-3 Panel Board and Board Cover

1.Before you remove these parts, you should remove:

-Face up cover and Front cover (see page 3-1)

2.From the front cover, remove two screws, then remove the board cover.

Panel board

Board cover

3-4 Transfer Roller

1. Open the front cover with hand.

3.To remove the transfer roller, pull up the tab to release the roller, then take it out.

2. Remove the transfer roller cap.

Cap

Samsung Electronics

3-3

Disassembly and Reassembly

3-5 Top Cover and Rear Cover

1.Before you remove these covers, you should remove:

-Face up cover and Front cover (see page 3-1)

2.Remove three screws.

3.Unlatch the tabs on the left and right side end of the cover, then take out the rear cover.

4. Remove two screws, and remove the top cover.

Unlatch the tabs at both sides to remove the cover.

3-6 Side Covers (Left, Right)

1.Before you remove these side covers, you should remove:

-Face up cover and Front cover (see page 3-1) -Top cover and Rear cover (see page 3-4)

2.Remove two screws on the back of the covers.

3.Unlatch the left and right side covers, and remove them.

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Disassembly and Reassembly

3-7 SMPS/Engine Control Board

1.Before you remove the board, you should remove:

-All covers (see pages 3-1, 3-4)

2.Turn the printer upside down.

3.Remove three screws securing the shield, then remove the shield.

4.Unplug all the connectors from the SMPS, then take out the SMPS and the engine board.

SMPS and

Engine board

Shield

3-8 Control Board

1. Before you remove the control board, you should remove:

-All covers (see pages 3-1, 3-4)

2. Unplug all the connectors from the control board,	Control Board
remove three screws, and take out the control
board.

Samsung Electronics

3-5

Disassembly and Reassembly

3-9 Joint Board

1.Before you remove the joint board, you should remove:

-All covers (see pages 3-1, 3-4) -SMPS (see page 3-5)

2.Unplug all connectors from the joint board, remove three screws, then remove the joint board.

3-10 Sensor Board

1.Before you remove the sensor board, you should remove:

-All covers (see pages 3-1, 3-4) -SMPS (see page 3-5)

2.Remove two screws, unplug all connectors from the sensor board, then remove the board.

3-6	Samsung Electronics

Disassembly and Reassembly

3-11 Gear Bracket

1. Before you remove the gear bracket, you should remove:

-All covers (see pages 3-1, 3-4)

2. Remove six screws securing the gear bracket, unplug the connector from the motor, then remove the gear bracket.

3-12 Motor

1. Before you remove the motor, you should	Motor
remove:
-All covers (see pages 3-1, 3-4)
-Gear bracket (see page 3-14)

2. Remove three screws, then remove the motor.

Gear bracket

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3-7

Disassembly and Reassembly

3-13 HVPS Board

1.Before you remove the HVPS board, you should remove:

-All covers (see pages 3-1, 3-4)

3.Unplug the connector from the HVPS board, then remove the board.

2. Remove five screws from the HVPS board.

High voltage electrodes

HVPS board

Note: When you reassemble the HVPS board, make sure that the high voltage electrodes are placed correctly.

3-14 LSU

1. Before you remove the LSU, you should remove: -All covers (see pages 3-1, 3-4)

2. Unplug two connectors, remove five screws, then take out the LSU.

LSU

3-8	Samsung Electronics

Disassembly and Reassembly

3-15 Fuser

1.Before you remove the fuser, you should remove: -All covers (see pages 3-1, 3-4)

2.Remove one screw securing the wire cap at the left side of the frame, unlatch the cap, then remove the cap.

4. Unlatch the tabs using a proper tool.

Wire cap

Unlatch these tabs.	5. Slide the fuser in the direction of arrow and take
	it out.

3. Remove four screws.

Samsung Electronics

3-9

Disassembly and Reassembly

3-16 Upper Frame

1.Before you remove the upper frame, you should remove:

-All covers (see pages 3-1, 3-4) -Gear bracket (see page 3-14) -HVPS board (see page 3-16)

2.Remove six screws, then remove two screws securing the solenoid.

3. Unlatch the front end of the frame, then lift it up.

Solenoid

3-17 Pressure Roller

1.Before you remove the roller, you should remove:

-All covers (see pages 3-1, 3-4)

-All boards (see pages 3-3, 3-5, 3-6, 3-8) -Upper frame (see page 3-10)

-Fuser (see page 3-9)

2. Remove the roller.

3-10	Samsung Electronics

Disassembly and Reassembly

3-18 Pickup Roller

1.Before you remove the pickup roller, you should remove:

-All covers (see pages 3-1, 3-4)

-All boards (see pages 3-3, 3-5, 3-6, 3-8) -Upper frame (see page 3-9)

2.Remove one screw, pull the pick-up bushing slightly toward you, then rotate it clock-wise.

3.Remove the E-ring at the right end of the roller.

4.Remove a pin passing through a shaft to take out the pick-up roller, then push the roller shaft to the right. Lift the left side of the roller, then take it out.

3-19 Installing SIMM

1.Before you install SIMM, make sure that printer power is off, all cables are unpluged. The toner cartridge is also to be removed.

2.Turn the printer upside down, and remove all screws securing the shield cover, then remove the shield cover.

Samsung Electronics

3-11

Disassembly and Reassembly

3. Locate the SIMM connector on the control board.

4.Hold the SIMM with the connection points and insert the SIMM all the way into the connector at 30o angle .

5. Push it firmly until it snaps into place.

Make sure both metal clips on the connector are fastened and the two pins on the connector are pushed through the holes on the SIMM.

Note: When you disassemble the SIMM, push out on the metal clips at each end of the connector and pull it toward you.

6. Reassemble the shield cover.

3-12	Samsung Electronics

4. Troubleshooting

4-1 Abnormal Image Printing and Defective Roller

If abnormal image prints periodically, check the parts shown below.

No	Roller	Abnormal image period	Kind of abnormal image
1	OPC Drum	94.3mm	White spot
2	Charge Roller	37.7mm	Black spot
3	Supply Roller	40.0mm	Horizontal density band
4	Develop Roller	46.1mm	Horizontal density band
5	Transfer Roller	47.1mm	Black side contamination/transfer fault
6	Heat Roller	56.1mm	Black spot and fuser ghost
7	Pressure Roller	56.2mm	Black side contamination

4-2 Print Quality

4-2-1 No Image

No image?	NO
YES
Self test	NO
pattern prints?

YES

Check connection to computer or replace controller.

Self testing		NO
is possible via
DCU?
	YES

Take out the cartridge and prepare the tester for electronic connection.

Is the OPC

terminal of machine NO well-connected

to Frame?

YES

A on next page

Re-test after replacing the conector or controller board.

Repair or replace the GND terminal.

Does the				Check the path between
video data line to		NO		video controller, engine board
LSU transit to High/Low				and HVPS. Repair or replace
when printing?				the defective component
	YES			or board.

The mirror in LSU might be misplaced so the light path to the OPC deviates ->Repair or replace LSU or remove any defective matters in the machine.

Samsung Electronics

4-1

Troubleshooting

A
		NO
Transfer
voltage OK? (on the
transfer roller
shaft)
	YES	Are the
					NO
		connection terminal					Repair or replace terminal.
		and connection
		correct?
				YES

Replace HVPS or repair defective component.

Developing

NO

NO

(-300V) and supplying

Is the connection

Repair or replace terminal.

(-500V) voltage

terminal OK?

are

OK?

YES

YES

Replace HVPS or repair

defective component.

Sealing tape	NO
is removed from the
cartridge?
YES

Does the

counter indicate over NO the toner's guarranty

life?

YES

Remove the tape.

Transfer roller might be out of its location. -> Locate the roller into its place.

This could occurrs when the power of LSU is low or the density is low due to the obstacles on the window -> Replace LSU or clean the window.

Replace the toner cartridge.

4-2	Samsung Electronics

									Troubleshooting
4-2-2 All Black
				Does the
All black in									Check the path among video
		NO	video data line to LSU				NO		controller, engine board,
printing area?			transit to High/ Low when						HVPS, LSU for the shortage
				printing?
									or open. -> Repair or replace
	YES				YES				the boards.
				Replace LSU.

Is transfer		NO
voltage supplied				Repair or replace HVPS.
from HVPS?
	YES

Is the		NO
				Replace LSU.
Hsync/ signal received
in LSU?
	YES

Transfer part's contact is bad. -> Repair or replace toner cartridge.

Samsung Electronics

4-3

Troubleshooting

4-2-3 Vertical White Line (Band)

			Check if the				The ribs in fuser or toner on the
							roller may invoke the image
White line		NO	printout is still has the		NO		problem. -> Replace the fuser
missing definitely?			same problem even right after				cover or the defective part.
			passed through the
			transfer roller.				The image is originally black or the
	YES						black part is far close to the top.
				YES			-> Use the pattern which has the
							image below bigger than 10mm
							from the top.

Dirt of dust stuck onto the window of internal lens of LSU -> Clean it or replace LSU.

Preventive obstacles through the path between OPC of developer and LSU prevent the path -> Remove the obstacles.

Toner material might be stuck to blade in the developer inside and it prevents toner supply -> Replace the developer.

Check both if the toner cartridge's counter is over its guaranty and amount of the toner material.

-> Replace the toner cartridge.

4-4	Samsung Electronics

4-2-4 Dark Image

NO	'Dark' selected
	via RCP?
	YES
	Change to
	'Normal' and test.
	Same at 'Normal'?	NO
	YES
	Works	NO
	correctly with
	-300V of Bias
	voltage?
	YES
	Works	NO
	correctly after
	replaced LSU?
	YES

The power of LSU is set high or internal problem. -> Replace LSU or adjust volume.

Troubleshooting

END

Repair or replace the defective component.

Toner over supply due to the adjustment fault of metering blade in developer.

-> Replace developer.

Samsung Electronics

4-5

Troubleshooting

4-2-5 Background

Recommended	NO		Print 20 to 30 pages using
paper used?			the recommended paper.

YES

- Adjust voltage or

NO

Transfer,

YES

Same

problem

NO

replace HVPS.

charge and developing

END

- Repair or replace

voltage are OK?

occurs?

after checking the

terminals' contacts.

YES

Operating/

NO

Dirt or

NO

storage atmosphere is

dust around the

Replace the

too high temperature

charge roller?

toner cartridge.

/humidity?

YES

YES

Solve the problem under the recommended condition (10-32 degree Centigrade).

Clean the charge roller

or replace step-up device /terminal after check.

Check terminals or contacts and 'Guide-Deve Spring'
are misplaced.	NO
-> Repair or replace transfer roller etc.			Work OK?

Check if the LED of PTL in front of the transfer roller

is on when it presses the top cover switch on purpose. YES -> If not, replace PTL.

Internal blade or suppying part of the developer is defective. -> Replace the toner cartridge.

4-6	Samsung Electronics

4-2-6 Ghost

Replace PTL assembly.

Check HVPS contacts and HVPS's selfoutput.

-> If failed, repair/replace HVPS.

Troubleshooting

	Is it regular		NO	Is it regular		NO	Is it regular
							interval of 47mm?
	interval of 94mm?			interval of 46mm?
							(as transfer roller
							interval)

YES

YES

NO	PTL lamp
	works OK?
		YES

				Developing
	NO	Transfer		/suppying voltage
				normal? (-300V/
		voltage is set to
				-500V)
		standard?
			YES		YES
				Irregularity of NIP
				between rollers in
				developer.
				-> Replace developer.

YES

A specific part of the transfer roller has ruined or its resistance value is changed. -> Replace transfer roller.

Transfer roller cannot force regularly due to the gears eccentricity of transfer roller. -> Replace the defective component.

NO

-Repair or replace HVPS .

-Check and repair or replace the terminal contacts.

Bias voltage		NO
is OK? (-300V)
	YES

Operating/storage NO temperature is too low or

not recommended paper used?

YES

Use the machine with recommended paper and at normal condition.

Adjust the Bias

voltage or replace

HVPS.

There may be a problem in toner layer control in toner cartridge.

-> Replace the developer.

Samsung Electronics

4-7

Troubleshooting

4-2-7 Black Dot

Is it regular			NO	When taking			NO	Bad image
				out the cartridge,				removes by
interval of 38mm?
				toner leaks?				scratching?
	YES				YES				YES

	NO			The problem
				randomly occured
				due to the toner
				fallen. -> Clean the
				machine.

The problem occured since the obstacles stuck to charge roller. -> Replace developer and C/R.

Toner leaks and toner material dropped onto the paper. -> Replace the developer.

Check toner is stuck onto the P/R or H/R in fuser. -> Clean it or replace.

4-2-8 Horizontal Band

NO

Black band?

YES

	The black		NO
	band has regular
	interval?
		YES

NO

94mm interval?

YES

The OPC is damaged due to the irregular transfer voltage of HVPS.

-> Repair/replace HVPS.

-> If the same problem persists, replace the developer.

	Black band		NO
	is far about 10mm	from
	white band?

Problem of internal contacts in OPC.

-> Replace developer.

This occurs when no Hsync/ at LSU.

-> Replace LSU.

The OPC is damaged under the direct sunlight for around 5 minutes. -> If the same problem persists in 10 hours, replace the developer.

Does it appear					Problems of terminal contact,
			NO		transfer voltage supplying,
at every 56.1mm		at			and transfer roller's due to the
specific place?					charge roller is ruined (38mm).
					-> Repair/replace HVPS,
	YES				developer.

Heat roller is ruined. -> Replace the roller.

4-8	Samsung Electronics