Samsung ML-5000 Troubleshooting

4. Troubleshooting

4-1 Abnormal Image Printing and Defective Roller

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

Samsung Electronics 4-1

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

Check connection to computer or replace controller.

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

Repair or replace the GND terminal.

Check the path between video controller, engine board and HVPS. Repair or replace the defective component 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.

Self test

pattern prints?

No image?

Self testing

is possible via

DCU?

Is the OPC

terminal of machine

well-connected

to Frame?

Does the

video data line to

LSU transit to High/Low

when printing?

Re-test after replacing the conector or controller board.

A on

YES

4-2 Print Quality

4-2-1 No Image

4-2 Samsung Electronics

Troubleshooting

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.

Transfer

voltage OK? (on the

transfer roller

shaft)

Are the

connection terminal

and connection

correct?

Repair or replace terminal.

Sealing tape

is removed from the

cartridge?

Replace HVPS or repair defective component.

Is the connection

terminal OK?

Replace HVPS or repair defective component.

Repair or replace terminal.

Remove the tape.

Developing

(-300V) and supplying

(-500V) voltage

are OK?

Does the

counter indicate over

the toner's guarranty

life?

Replace the toner cartridge.

YES

4-3

Samsung Electronics

Troubleshooting

All black in

printing area?

Is transfer

voltage supplied

from HVPS?

Is the

Hsync/ signal received

in LSU?

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

Does the

video data line to LSU

transit to High/ Low when

printing?

Replace LSU.

Check the path among video controller, engine board, HVPS, LSU for the shortage or open. -> Repair or replace the boards.

Repair or replace HVPS.

Replace LSU.

YES

4-2-2 All Black

4-4 Samsung Electronics

Troubleshooting

White line

missing definitely?

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.

Check if the

printout is still has the

same problem even right after

passed through the

transfer roller.

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.

The ribs in fuser or toner on the roller may invoke the image problem. -> Replace the fuser cover or the defective part.

The image is originally black or the black part is far close to the top.

-> Use the pattern which has the image below bigger than 10mm from the top.

YES

4-2-3 Vertical White Line (Band)

4-5Samsung Electronics

Troubleshooting

'Dark' selected

via RCP?

Change to

'Normal' and test.

Works

correctly with

-300V of Bias voltage?

Works

correctly after

replaced LSU?

Repair or replace the defective component.

The power of LSU is set high or internal problem.

-> Replace LSU or adjust volume.

Same at 'Normal'?

END

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

-> Replace developer.

YES

4-2-4 Dark Image

4-6 Samsung Electronics

Troubleshooting

Recommended

paper used?

Transfer,

charge and developing

voltage are OK?

Operating/

storage atmosphere is

too high temperature

/humidity?

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

Dirt or

dust around the

charge roller?

Clean the charge roller or replace step-up device /terminal after check.

Work OK?

Internal blade or suppying part of the developer is defective.

-> Replace the toner cartridge.

Check terminals or contacts and 'Guide-Deve Spring' are misplaced.

-> Repair or replace transfer roller etc.

Check if the LED of PTL in front of the transfer roller is on when it presses the top cover switch on purpose.

-> If not, replace PTL.

Print 20 to 30 pages using the recommended paper.

Same problem

occurs?

- Adjust voltage or replace HVPS.

- Repair or replace after checking the terminals' contacts.

END

Replace the toner cartridge.

NO NO

YES

4-2-5 Background

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