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Lexmark C720 Troubleshooting Manual

Made by: Lexmark
Type: Troubleshooting Guide
Category: Printer
Pages: 15
Size: 0.34 MB

 

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Using color

Paper handling

Maintenance

Troubleshooting

Administration

Printing

Index

 Solving printing problems

1

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Lexmark C720

Some printer problems are very easy to solve. If your printer is not responding, first make 
sure:

The printer cable is securely attached to the printer and the host computer.

The power cord is plugged into the printer and a properly grounded electrical outlet.

The printer is turned on.

The electrical outlet is not turned off by any switch or breaker.

The printer front, top, and rear doors are completely closed.

All printer options are properly installed.

Once you’ve checked each of these possibilities, turn the printer off and back on. This often 
fixes the problem.

If a message appears on the operator panel display, see 

Understanding printer messages

 

for more information. If the message indicates the printer has a paper jam, see 

Clearing 

paper jams

.

If you are having trouble determining the source of the problem, see 

Print quality problems 

for other suggestions.

 


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Lexmark C720

The information in the following tables may help you solve printing problems. If these 
suggestions do not correct the problem, call for service. You may have a printer part that 
requires adjustment or replacement.

Toner cartridge problems

Problem

Action

You cannot insert a toner 
cartridge into the printer.

Make sure the toner cartridge is aligned properly and is being 
installed in the correct location. See 

Replacing toner cartridges 

for 

more information.

Toner accumulates inside the 
printer.

Replace the toner cartridge that matches the color of the toner that 
has accumulated inside the printer. See 

Replacing toner 

cartridges

 


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Print quality problems

Problem

Action

Print is too light, or printed 
images or characters have 
voids or dropouts.

Make sure the front, top, and rear doors are closed completely.

Make sure you’re using 

recommended paper

 or other 

media

. Use 

media from a new package.

Make sure you have selected the correct 

Paper Type

 setting for the 

media you’re using.

If you suspect a toner cartridge is low on toner, remove the 
appropriate cartridge and gently shake it back-and-forth to distribute 
the toner evenly. Reinsert the cartridge and try printing the job again.

Replace the toner cartridge that matches the color on the page that 
is too light or not present in the void areas. See 

Replacing the toner 

cartridge

 


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Colored lines, streaks, or 
smudges appear on the 
printed page, or print appears 
blurred or unclear.

Replace the toner cartridge that matches the color of the lines, 
streaks, or smudges on the page. See 

Replacing toner cartridges

.

Clean the photo developer discharger. See 

Cleaning the photo 

developer charger.

Make sure the the drum cleaner is fully seated. See 

Replace the 

drum cleaner

.

The page has 100% 
coverage of one color.

Replace the toner cartridge that matches the color on the page. See 

Replacing toner cartridges

.

Print quality problems (continued)

Problem

Action

 


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Lexmark C720

Light lines or streaks appear 
on the printed page.

Remove the toner cartridge that matches the color of the lines or 
streaks and gently shake it back and forth to distribute the toner 
evenly. Reinsert the toner cartridge and try printing the job again.

Replace the toner cartridge that matches the color of the lines or 
streaks on the page. See 

Replacing toner cartridges

If the lines are black, you may need to replace the fuser. See 

Fuser 

and air filter 

for more information.

Light lines or voids appear 
from the top of the page to 
the bottom of the page.

Remove the photo developer cartridge and clean the dust from the 
photo developer cartridge discharger. (See 

Cleaning the photo 

developer charger

.) Reinsert the photo developer cartridge and try 

printing the job again.

The toner cartridge may be low on toner, remove the cartridge, shake 
it, and reinsert it. If the problem still occurs, replace the toner 
cartridge. See 

Replacing toner cartridges

.

Replace the photo developer cartridge. See 

Replacing the photo 

developer cartridge

Print quality problems (continued)

Problem

Action

 


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The page is blank or one of 
the colors is missing.

Replace the toner cartridge that matches the missing color on the 
page. See 

Replacing toner cartridges

.

Toner smears or rubs off the 
page.

Make sure you’re using 

recommended paper

 or other 

media

.

Make sure you have selected the correct 

Paper Type

 setting for the 

media you’re using.

Make sure the rear door is completely closed.

Print quality problems (continued)

Problem

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Lexmark C720

Toner adheres to the back of 
the page.

Make sure the paper size is set properly for the paper length you are 
printing on. Print several pages to clean the transfer roller of excess 
toner.

You may need to replace the fuser. See 

Fuser and air filter 

for more 

information.

Printed materials delivered 
by the postal service arrive 
with ghosting or mirror 
images of the text visible on 
the page.

When preparing printed materials for mailing:

• Use 24 lb (90 g/m

2

) paper.

• Avoid rough paper; select paper with a smoothness from 100 to 

150 Sheffield points.

• Fold sheets with the text facing outward.

• Meter envelopes or use precanceled stamps.

• Place envelopes in trays and deliver to the post office; do not 

drop envelopes into mail boxes or chutes.

Print quality problems (continued)

Problem

Action

 


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Lexmark C720

Quality of printed 
transparencies is inadequate.

Make sure you’re using the recommended Lexmark transparencies. 
See 

Transparencies

 for more information.

When printing transparencies, always set Paper Type to 
Transparency.

Avoid getting fingerprints on transparencies before printing.

Print on the page is skewed.

Make sure the width guides in the paper tray fit snugly against the 
media you loaded. See 

Loading media

 for more information.

Print quality problems (continued)

Problem

Action

 


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Lexmark C720

Quality of printed images is 
inadequate.

If you’re printing low resolution images using PostScript 3 emulation, 
set Image Smoothing On. See 

PostScript Menu

 for more 

information.

A white gap is noticeable 
between color fills.

Make sure the three printer foot pads are resting on a level surface.

Print quality problems (continued)

Problem

Action

 


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Lexmark C720

Colors do not print as you 
expect.

Make sure you have selected the appropriate Color Correction and 
Print Quality values for the job you’re printing. See 

Color Menu

 for 

more information.

Print quality problems (continued)

Problem

Action

 


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Lexmark C720

Other printing problems

Problem

Action

Your job did not print or 
incorrect characters printed.

Make sure 

Ready

 (or 

Power Saver

) appears on the first line of the 

operator panel display before you send a job to print. Press Go to 
return the printer to the ready state. 

If 

Ready Hex

 appears on the operator panel display, you must exit 

Hex Trace mode before you can print your job. To exit Hex Trace 
mode, reset the printer or turn the printer off and back on.

Make sure the printer is not displaying a 

Toner Empty

 message. If it 

is, you cannot print until you replace the specified toner cartridge.

If you’re using a parallel interface, make sure you’re using an IEEE 
1284-compliant parallel cable. We recommend Lexmark part number 
1329605 (10 ft) or 1427498 (20 ft) for the standard parallel port.

If you’re using a Lexmark internal or external network adapter, verify 
it is set up properly and the network cable is securely connected. 
Refer to the documentation that came with your adapter, or the 
network documentation on the Drivers CD for more information.

You cannot print color.

Make sure the Color Correction menu item is not set to Black and 
White.

Make sure you’re using a color printer driver.

Make sure color printing is selected from the printer driver.

 


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Lexmark C720

You cannot print the menu 
settings page.

Make sure the selected paper source holds A4, letter, or legal size 
paper. Make sure the Paper Type setting for the selected source is 
Plain Paper.

You cannot print using the 
LocalTalk port.

Make sure neither LocalTalk Port nor LocalTalk Buffer is set to 
Disabled in the LocalTalk Menu.

Verify the printer is set up correctly in the Macintosh Chooser.

Paper does not feed properly. Make sure you’re using recommended media. If you are using 16 lb 

paper, make sure it has been placed in tray 1 only. Do not use 16 lb 
paper with the duplex unit.

Make sure the adjustable guides in the paper tray are adjusted 
properly for the media you loaded.

Make sure the stack of media does not exceed the maximum stack 
height indicated on the tray.

Other printing problems (continued)

Problem

Action

 


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The printer seems slow to 
print.

If Photo Enhance is On, it may take longer to print some complex 
jobs or jobs formatted for larger paper. You can set Photo Enhance to 
Off and select the 600 dpi setting if you need the job to print faster. 
See 

Photo Enhance

 for more information.

Make sure you select the appropriate Paper Type setting before 
sending a job to print.

If the Paper Type is set to Transparency, the printer adjusts the fuser 
temperature and slows printing to improve the print quality. After 
printing on this media, the printer requires additional time to warm 
the fuser after you select another Paper Type setting (such as Plain 
Paper or Letterhead).

Reduce the complexity of your print job. Eliminating the number and 
size of fonts, the number and complexity of images, and the number 
of pages in a job may increase print speed.

Set Page Protect Off from the Setup Menu. See 

Page Protect

 for 

more information.

Other printing problems (continued)

Problem

Action

 


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You can’t collate a large job.

Reduce the complexity of your print job. Eliminate the number and 
size of fonts, the number and complexity of images, and the number 
of pages.

Add more printer memory. See 

Adding memory

 or refer to the 

Setup Guide for more information.

Install an optional hard disk in your printer. See 

Hard disk

, or refer to 

the Setup Guide for more information.

You get unexpected page 
breaks.

Increase the Print Timeout value in the 

Setup Menu

.

Transparencies curl 
excessively.

Make sure you’re using the recommended Lexmark transparencies. 
See 

Transparencies

 for more information.

Transparencies jam.

Fan transparencies before loading. Make sure you load 
transparencies only in tray 1. See 

Loading transparencies 

for more 

information.

If you just turned the printer on or the printer has been idle for a 
period of time, print on paper before trying to print on transparencies.

Disabling Power Saver may also prevent transparencies from 
jamming after the printer has been idle. See 

Power Saver

 for more 

information.

Other printing problems (continued)

Problem

Action

 


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Lexmark C720

Paper is jammed in the fuser.

Open the fuser unit roller latches and remove the jammed paper. See 

202 paper jam (fuser and output rollers)

 for more information.

You cannot clear the paper 
jam message.

To clear the paper jam messages, you must remove all paper from 
the printer paper path. Check both inside the printer as well as the 
paper source you were using. Paper may jam at the rear of the paper 
tray, remove the tray and look inside for jammed paper. Then open 
and close the rear door and top door and press 

Go

. See 

Clearing 

printer paper jams.

The page that jammed does 
not reprint after you clear the 
jam.

Set Jam Recovery to Auto or to On in the Setup Menu. See 

Auto 

Continue

 for more information.

Part of the printed page was 
clipped or is cut off.

Make sure you have the correct size paper in the paper tray and the 
paper size is set correctly for the paper in the tray.

Make sure auto sensing is On unless you have a legal tray installed 
or are using a paper size that is not supported in auto sensing.

Other printing problems (continued)

Problem

Action