Lexmark C720 SERIES User manual

Using color
Paper handling
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Troubleshooting
Administration
Printing
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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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Solving printing problems 2
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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.
Toneraccumulatesinside 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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Solving printing problems 3
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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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Solving printing problems 4
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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)
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Solving printing problems 5
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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)
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Solving printing problems 6
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Lexmark C720
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)
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Solving printing problems 7
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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/m2) 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)
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Solving printing problems 8
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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)
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Solving printing problems 9
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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)
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Solving printing problems 10
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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)
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Solving printing problems 11
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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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Solving printing problems 12
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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)
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Solving printing problems 13
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Lexmark C720
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)
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Solving printing problems 14
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Lexmark C720
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)
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Solving printing problems 15
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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