Oki B840dn User Manual - page 71

Troubleshooting > 71

P

RINT

QUALITY

PROBLEMS

Before consulting a service representative regarding a print quality problem, check the 

table below to see if there is a solution, or something you might have overlooked.

SYMPTOM

PROBLEM

SOLUTION

Blank sheets printed.

Image drum cartridge 

not properly installed.

Reinstall image drum cartridge.

Empty toner cartridge.

Replace with a new EP toner cartridge.

Entire page prints 

faintly.

Empty toner cartridge. 

Pages get fainter when 

toner is used up.

Replace with a new EP toner cartridge.

LED array is dirty.

Clean LED array.

Page has grey 

background.

Static electricity, 

generally from dry 

environments, causes 

toner to stick to 

background.

Change paper to a smoother laser bond or 

use a humidifier.

Page prints all black.

Hardware problem.

Contact service.

Oblong area of faint 

print appears on 

each page.

Drop out caused by 

using paper exposed to 

high humidity.

Change paper stocks, check paper storage 

environment or use a dehumidifier; check 

toner level.

Vertical white 

streaking or faint 

areas on page.

Toner is low and does 

not distribute properly, 

or the drum is worn out.

Replace with a new EP toner cartridge.

Contact service.

LED array is dirty.

Clean LED array.

Vertical black lines.

Hardware problem.

Contact service.

Fuzzy print.

LED array is dirty.

Clean LED array.

Faded print.

Toner low.

Replace with a new EP toner cartridge.

Smeared or blotched 

print.

Dirty rollers; toner 

dropped inside printer or 

image drum problem.

Replace with a new EP toner cartridge.

Contact service.

Printed page is light/

blurred.

Is toner low?

Replace with a new EP toner cartridge.

Is paper meant for laser 

printers?

Use recommended paper.

LED array is dirty.

Clean LED array.

Bold characters and 

dark lines are 

smeared.

Toner is low.

Replace with a new EP toner cartridge.

Print is darker than 

usual.

Darkness setting is too 

high.

Change darkness setting.

Pages curl 

excessively.

Printing on wrong side 

of paper.

Turn paper over in tray. (Note arrow on 

paper package). Install paper print side 

down in tray.

Moisture in paper. 

Improper storage.

Avoid storing paper in areas of excessive 

temperature and humidity. Store paper in 

protective wrapping.

High humidity.

Recommended operating humidity: 20-

80%.