Question about OKI C5100n Laser Printer

1 Answer

Not printing black

I'm having the same problem except I've changed both the toner cartridge and drum and still not printing black. You say to clean the leeds ... um .... not to sound dumb but where in the world is that? Is that the connection areas on the drum? Did that. I gently cleaned the "bar" that hangs down from the lid when you open it. Still not printing black. Adjusted the registration a couple of times. Still not printing black. All other colors printing including the Cyan that says is out. Thank you for your assistance.

Posted by hicksinfo on

  • hicksinfo Jul 01, 2008

    I FINALLY was able to get through to Okidata and they suggested a service person also. The quick fix is to have a service person change the LED's around and if that's the problem it would be $60 - 100 and would take 10 minutes. If it doesn't then the board fix is about $500. Now if I can figure out how to change the LED's myself to figure out if that's the problem that would be cool. Thanks for the reply.



1 Answer

Jose Pais

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert who has answered 20 questions.


    An expert that has over 10 points.


    An expert whose answer got voted for 2 times.

  • Expert
  • 114 Answers

It´s pretty strange but if u replaced both toner and drum, the printer doesn´t give any error u may have the high voltage board damaged, and u can't do much, u must contact a local dealer

Posted on Jul 01, 2008

  • Jose Pais
    Jose Pais Jul 01, 2008

    it´s easy to change it

    and u can just swap with other one

    just remove the flat cable carefully

    good luck



Add Your Answer


Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:


4 black lines at every print

Mostly black lines prints due to problem in the Black toner cartridge. remove the Black toner out and inspect the toner drum, whether are their any black patch on the toner drum. If it so there's a problem in the black toner. Replace a new black toner and check.

My Brother MFC-7420 Printer always prints black lines and splotches down the left side of my paper. This happens whether I'm scanning or printing from my PC. When I looked at my drum, it appears a

If you are seeing vertical streaks/black lines your primary corona wire is dirty and or the fax scanner may be dirty.
1)To clean the corona wire you take the drum unit and toner cartridge and place it on disposable paper to avoid spilling.
2) Clean the primary corona wire inside the drum unit by sliding the blue tab from right to left several times.
3) Return the blue tab and snap it into the home position.
4) Reinstall the drum unit and toner cartridge.
5) Close the front cover.
Caution: if you do not return the blue tab to the home position it may repeat the black lines.

Print copy is very light. Is there an adjustment?

Usually light prints on a Brother just mean a bad toner cartridge, but try these first:
  • Most Brother drum units have a slider that you push back and forth. It's probably blue plastic. Sliding that wipes dust off a charging wire in the drum unit, where cleanliness is essential to getting a clean, dark print.
  • While you have the drum & toner out, look inside the machine for short, shiny steel wires on the inside walls. Those wires contact metal in the drum unit to transfer the high voltages required to get toner onto the paper. Clean those wires and contacts with a little wire brush or even a pencil eraser. Chances are, you've been pulling out your toner/drum assembly while this problem has been bothering you, and that has probably cleaned all the contacts enough.
  • Look at the slot in the top of the drum unit where you can look in and see the drum. The laser shines down through that slot to draw the image on the drum that will eventually be your print. Look up into the top of the chamber where the drum-toner sits, and you'll find a skinny glass window. Gently wipe that clean. Any dust or toner there will lighten your print. Be careful not to knock any of the tiny, black levers that stick up into the bottom of the area. Those are paper sensors, and they have to be delicate, so they can be moved by the paper passing over them.
I expect that none of these will help, and you'll have to get a new toner cartridge. If the old cartridge is still new, take it back to the store along with print samples. Maybe even bring the printer so they can test their toner themselves. They might just swap it for a fresh one; it's worth a try.

My Brother HL 4040cn printer is leaking toner, black and yellow. It leaves spatter spots of these colors on printed pages. The machine does not have any messages. Do you know what this may be from or how...

If you've taken the printer apart and cleaned the belt unit and everywhere else in the paper's path, then it is probably either a bad toner cartridge or the drum. Since it's multiple colors producing splatter, its most likely the drum unit. Try taking the drum out and removing all of the toner cartridges and then clean the drums and corona wires. If its still producing splatter afterward, you've got yourself a bad drum.

Why is there black line printed across the page in 3 different areas when something is printed. I changed the toner catridge.

This is nearly always the fault of the toner cartridge. The previous cartridge may have left toner on the transfer roller and this may have contaminated the new toner cartridge. Take the toner cartridge out and inside the printer under where the toner cartridge goes you will see a felt roller that goes across the printer and has a gear at one end. Wipe this roller with a dry clean lint free cloth, rotating it to make sure it is completly clean.
Check the blue coloured drum on the toner cartridge to see if there is a black line going across it. If so clean it with the same dry clean cloth.
If this does not work then I suggest you buy a genuine toner cartridge and try that.

Black smudges down left side of page

How do I clean white or black spots on printed documents? Description: First make 10 to 15 copies of a blank, white sheet of paper.
If you still see the spots on printed documents after making multiple copies, clean the drum unit as follows:

  1. Remove the drum unit and toner cartridge assembly, and then remove the toner cartridge from the drum unit.
  2. Position the print sample in front of the drum unit so you will know the exact position on the drum that is causing the poor print.
  3. all-ug-19.gif
  4. Turn the black gear on the drum as you check the surface of the OPC drum.
    The OPC drum is photosensitive so do not touch it with your fingers.
  5. all-ug-20.gif
  6. When you find the substance on the drum surface that matches the print sample, gently dab the surface of the OPC drum with a cotton swab that is lightly dampened with isopropyl alcohol.
  7. Note
      • Do not use a scrubbing or wiping motion because this might damage the drum.
      • Do not try to clean the surface of the OPC drum with a sharp object, such as a ball-point pen, because this might cause permanent damage to the drum unit.
  8. If the print quality still has not improved you need to install a new drum.

Sharp Z-70 copier - print outs are mostly black?

Check the dum cleaning blade. Usually the blade becomes weak and does not clean the drum properly. You can either replace just the drum blade or replace the entire drum cartridge.
If the copies are coming out solid black, then either the exposure lamp or the thermal fuse for the exposure lamp is/are burned out.

Installed new toner. Printer prints well, except approx 1 inch of vertical line doesn't print about 1/2 inch from right margin. Have gently shaken cartridge, run a cleaning paper, reiserted cartridge.

Assuming none of your print area margin settings have been changed, it sounds like you may have a defective drum. You can try carefully cleaning the corona wire, a hair thin wire, with a dry cotton swab. Do not touch the drum! The drum is an integral part of the toner cartridge. Return it to the store as defective.

Printer is printing entire page black

  1. clean the cartridge properly.
  2. take the waste toner from waste section
  3. change drum
  4. change chip
  5. do it this i think your probalem is solved
new problem

  • changed black cartridge but print color mixed print out
what i do? send the details to my email
Not finding what you are looking for?
OKI C5100n Laser Printer Logo


Ask a Question

Usually answered in minutes!

Top OKI Office Equipment & Supplies Experts

WTF Chuck.....
WTF Chuck.....

Level 3 Expert

388 Answers


Level 3 Expert

13435 Answers

Alvin Barnabas
Alvin Barnabas

Level 2 Expert

136 Answers

Are you an OKI Office Equipment and Supply Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides