Thank you for your feedback

Lexmark MS71x, MS81x, MX71x, & MX81x – A Black Line of Toner Can Be Seen Down the Page or Part of the Page Is Covered in Toner

Document ID:SO7520

Usergroup :External
05/08/14 Properties  


Sunlight into printer; Black line down page; How to install fan cover; Poor print quality; Vertical streaks; Leaking toner; Vertical line appears on printed page; Continuous line from top to bottom of the page


What you will see

Single or multiple vertical lines of toner appear on the page, or also one side of the page will be black. See examples below:

Click Image to Enlarge
Example of print defect due to light exposure.



Possible causes

NOTE: Click the link to view resolution below.



Recommended solution

Reseat the toner cartridge

The toner cartridge or Imaging Unit (IU) may not be seated correctly. This type of print quality issue can often be resolved by just reseating the supplies. When installing the supplies, make sure the left and right sides of the cartridge/IU are in all the way. The cartridge/IU should click into place when correctly installed.


Bright light/sunlight entering the printer

Light can enter the printer through the vent for the fan inlet. If too much light gets inside the area pointed to by the red arrow in the image below, the printer may exhibit the print quality issues described in this document. Hence, it is recommended to position the right-hand side of the printer away from bright light, especially sunlight.

Click Image to Enlarge

 If, however, the printer cannot be moved or relocated, a cover can be added to the fan inlet vent to help block light from entering the printer.

NOTE: For information on how to obtain this cover piece – Part Number: 41X0053 – please contact Lexmark Technical Support. See 'Contacting Lexmark' at the end of this document for details. The subsequent section will show you how to properly install the fan cover.


How to Install Fan Cover on a Lexmark MS71x, MS81x, MX71x, & MX81x

NOTE: This part is customer-installable without the use of any tool. No dismantling of the printer is required when installing it.

Step Action Click Image to Enlarge

Familiarize yourself with the cover piece. The cover can only be installed one way. The correct orientation is marked on the back with an arrow and the word "UP".

2 Install the bottom of the cover onto the hooks on the bottom of the vent.
3 Rotate the top of the cover into place and secure the cover at all four latch points. Make sure the cover is securely installed.


Contacting Lexmark

If you require additional assistance, please close this window and locate  Get In Touch with Lexmark! for contact information. NOTE: When calling for support, you will need your printer model/machine type and serial number (SN). If you need help locating these, click here.

Please be near the products described in this article to expedite the support process and reduce callbacks.


Please enter the email address you would like to send a copy of this page to.