Samsung SCX 4200-XAX Troubleshootin

Troubleshooting

Samsung Electronics

Service Manual

6-1

6. Troubleshooting

6.1 Printing Problems – Causes and Solutions

6.1.1 Vertical Black Lines and Bands

• Description

1. Straight thin black vertical lines occur in the printing.

2. Dark black vertical bands occur in the printing.

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Check and Cause Solution

1. Damaged developer roller, deformed Doctor-blade in the Toner cartridge.

2. Scratched surface of the charge roller in the toner cartridge.

1. Replace the toner cartridge and test again.

2. Replace the toner cartridge and test again.

6.1.2 Vertical White Line

• Description White vertical voids in the image.

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Check and Cause Solution

1. 1. Contamination of the window or internal lenses of LSU mirror.

2. Foreign object inside the toner cartridge or low toner.

3. Foreign object, contamination or burr on the edge of the toner cartridge window.

4. If the fuser is defective, voids occur periodically at the top of a black image.

5. Contamination of the OPC drum.

1. Clean the LSU window with recommended cleaner (IPA) Clean the window with a clean cotton swab. If dirt is inside the LSU – replace LSU.

2. Replace the toner cartridge.

3. Clean the exposure window.

4. Open the front cover and check the ribs that correspond to the position of the voids. Remove if found.

5. If the problems are not solved, replace the toner cartridge.

Samsung Electronics

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Troubleshooting

6-2

6.1.3 Horizontal Black Bands

• Description

1. Dark or blurry horizontal stripes occur in the printing periodically. (These may occur at regular intervals down the page.)

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Check and Cause Solution

1. Bad contacts on the toner cartridge high voltage terminals.

2. The rollers in the toner cartridge may be contaminated. Charge roller = 37.8 mm Supply roller = 44.9 mm Develop roller = 35.2 mm Transfer roller = 45.3 mm

1. Clean all HV terminals on the cartridge and on the set frame. Ensure all toner or paper dust particles are removed.

2. Clean the right Gear that has relatively small tooth gap on the OPC.

3. If the problem persists replace the toner cartridge.

6.1.4 Black/White Spot

• Description

1. Dark or blurry black spots occur periodically in the printing.

2. White spots occur periodically in the printing.

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Check and Cause Solution

1. If dark or blurry black spots occur periodically, the rollers in the Developer may be contaminated with foreign matte or paper particles. ( Charge roller : 37.8 mm interval

OPC drum : 75.5 mm interval)

2. If faded areas or voids occur in a black image at intervals of 75.5 mm, or black spots occur elsewhere, the OPC drum surface is damaged.

3. If a black image is partially broken, the transfer voltage is abnormal or the transfer roller's life has expired.

1. Print several OPC cleaning Mode Prints and then run the Self-test 2 or 3 times.

2. 75.5 mm repetition: Examine the surface of the OPC drum and carefully clean with a soft, lint free cloth. If unsuccessful replace the cartridge.

37.8mm repetition: Replace the toner cartridge

3. The transfer roller guarantees 50,000 sheets printing. If the roller's life is expired, replace it.

Note. Cleaning the inside of the set to

remove excess toner particles or paper dust will reduce the occurrence of this problem..

Troubleshooting

Samsung Electronics

Service Manual

6-3

6.1.5 Light Image

• Description The printed image is light, with no ghost.

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Check and Cause Solution

1. Toner Save mode enabled

2. Develop roller is contaminated or the toner cartridge is almost empty.

3. Ambient temperature is below than 10°C.

4. Bad contact caused by dirty terminals on the toner cartridge or set.

5. Abnormal output from the HVPS. (Run EDC mode – see sections 6.1.2 and 6.1.3)

1. Ensure the Toner Save mode is off. Check set and driver settings.

2. Replace the toner cartridge and try to print out again.

3. Wait 30 minutes after printer is powered on before you start printing.

4. Clean the cartridge and set contacts. Generally clean dirt from inside the set.

5. Replace the HVPS if the problems are not solved by the above four instructions.

6.1.6 Dark Image or a Black

• Description The printed image is dark.

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Check and Cause Solution

1. No charge voltage in the engine board.

2. Charge voltage fault due to bad contact between toner cartridge and set contacts.

3. VD0 signal of the Main PBA is Low state.

1. Check the state of the connector which connects the engine board and HVPS.

2. Clean the high voltage charge terminals.

Note if 1 and 2 do not resolve the problem

and the problem persists replace the HVPS.

3. Replace the LSU Unit or Main PBA.

Samsung Electronics

Service Manual

Troubleshooting

6-4

6.1.7 Uneven Density

• Description Print density is uneven between left and right.

Check and Cause Solution

1. The pressure force on the left and right springs of the transfer roller is not even, the springs are damaged, the transfer roller is improperly installed, or the transfer roller bushing or holders are damaged.

2. The life of the Toner cartridge has expired.

3. The toner level is not even on the toner cartridge roller due to the damaged blade or low toner.

1. Replace both the left and right bush and spring assemblies.

2. Replace the toner cartridge and try to print out

3. Gently shake the toner cartridge and try printing again. If the problem persists replace the toner cartridge.

6.1.8 Background

• Description Light dark background appears in whole area of the printing.

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Check and Cause Solution

1. Printing large quantities of low coverage (2%) pages or the printer has not been used for a long time.

Is a recycled toner cartridge be used?

Has the life span of the toner cartridge ended?

Is the movement(Up and Down) of the transfer roller smooth?

5. Is the HVPS normal?

1. The toner cartridge is basically designed to print 3,000 sheets with 5% image. If it prints more than 3,600 sheets with 2% coverage, a background can occur.

2. The A/S is not guaranteed if using a recycled toner cartridge.

Note try shaking the toner cartridge gently

from side to side. If the problem persists replace the toner cartridge.

3. Replace the toner cartridge when its life is expired.

4. Clean the transfer roller bushes.

5. Clean the high voltage charge terminals. If this does not resolve the problem replace the HVPS.

Troubleshooting

Samsung Electronics

Service Manual

6-5

6.1.9 Ghost (1)

• Description Ghost occurs at 75.5 mm intervals of the OPC drum in the whole printing.

Digital Printer

75.5 mm

Check and Cause Solution

1. Bad contacts caused by contamination from toner particles between high voltage terminal in the main body and the electrode of the Toner cartridge.

2. Bad contacts caused by contamination from toner particles between high voltage terminal in the main body and the one in the HVPS board.

3. The life of toner cartridge is expired.

4. Transfer roller life (50,000 sheets) has expired.

5. Low ambient temperature (below 10°C).

1 and 2. Clean all HV contacts, If problem persists replace the HVPS.

If problem still persists replace the Main PBA

3. Replace the toner cartridge and try to print out.

4. Check the transfer roller lifetime and replace it.

5. Wait about 30 minutes after power on before using printer.

6.1.10 Ghost (2)

• Description

Ghost occurs at 75.5mm intervals of the OPC drum in the whole printing. (When printing on card stock or transparencies using manual feeder)

Digital Printer

75 mm

Check and Cause Solution

When printing on card stock, thicker than normal paper or transparencies, such as OHP, a higher transfer voltage is required.

Ensure that the correct paper type is selected in the printer driver or application software. Remember to set back to normal paper after use.

Samsung Electronics

Service Manual

Troubleshooting

6-6

6.1.11 Ghost (3)

• Description Ghost occurs at 64 mm intervals.

Digital Printer

64 mm

Check and Cause Solution

1. Disassemble the fuser and remove any contamination on the rollers. Clean any contamination from between the Thermistor and the Heat roller. (Caution: Take care not to deform the rollers.)

Fuser contamination.

6.1.13 Stains on the Face of the Page

• Description The background on the face of the printed page is stained.

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Check and Cause Solution

1. Toner leakage due to improperly sealed toner cartridge.

1. Replace the toner cartridge.

2. If the transfer roller is contaminated, run PC Cleaning Mode Print 2 or 3 times and then perform Self-Test 2 or 3 times to remove contamination.

6.3.12 Ghost (4)

• Description A White ghost occurs in a black image printing at 35.2mm intervals.

Digital Printer

35.5 mm

Check and Cause Solution

1. Problem in the toner cartridge, replace the toner cartridge and try to print out again.

2. Check the HVPS supply voltage. Clean all HV terminals on the cartridge and on the set. Replace the HVPS if the problem persists.

1. The life of the developer may be expired.

2. Abnormal output from the HVPS. (Run EDC mode – see sections 6.1.2)

Troubleshooting

Samsung Electronics

Service Manual

6-7

6.1.14 Stains on Back of Page

• Description The back of the page is stained at 45.3 or 75.3 mm intervals.

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Check and Cause Solution

1. 45.3mm : Transfer roller is contaminated.

2. 75.3mm : Pressure roller is contaminated.

1. Perform the OPC Cleaning Mode Print 2 or 3 times. Run Self-Test to remove the contamination from the transfer roller.

Note. Replace the transfer roller if

contaminated severely.

2. Disassemble the fuser and clean the H/R(Heat Roller) and P/R(Pressure roller). Check and clean the area between the H/R and the Thermistor. (Caution: Take care not to deform the rollers.)

6.1.15 Blank Page Print out (1)

• Description Blank page is printed.

Check and Cause Solution

Bad ground contacts in OPC and/or toner cartridge.

1. Check if the Ground-OPC or the OPC Ground Zener diode are defective or open circuit. (set inside left side).

2. Remove contamination of the terminals on the toner cartridge and the unit.

6.1.16 Blank Page Print out (2)

• Description

1. Blank page is printed.

2. One or several blank pages are printed.

3. When the printer turns on, several blank pages print.

Check and Cause Solution

1. Abnormal solenoid.

1. Perform the engine self test using TECH Mode to check if the Solenoid is normal. If the problem persists replace the main PBA

Samsung Electronics

Service Manual

Troubleshooting

6-8

6.2.1 White Copy

• Description

Blank page is printed out when copying.

6.2 Copy Problems

6.2.2 Black Copy

• Description

Black page is printed out when Copying.

Check and Cause Solution

1. Check for CIS problem on the Main PBA.

2. Check shading profile.

1. Check the CIS harness is properly connected.

2. Redo shading profile in the tech mode.

Check and Cause Solution

1. Check the Scanner Cover is properly closed.

2. Check shading profile.

3. Check white/black reference voltage on Main PBA. e.q

• CIS_SI, CIS_CLK at CN8

• Or Check the FFC

1. Room light can pass through a thin original.

2. Redo shading profile in the tech mode.

3. Replace CN8 if it is defective.

• CN8-Pin6(CIS-SI)

• CN8-Pin7(CIS-CLK)

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