Brother 7820 N Manual

Troubleshooting and routine maintenance11 - 16
11
Improving the print quality
Examples of poor print qualityRecommendation
Faint
Check the machine’s environment. Conditions such as humidity, high 
temperatures, and so on may cause this print fault. (See  Choosing a location on 
page 1-2.)
If the whole page is too light,  Toner Save mode may be on. Turn off  Toner Save 
mode in the machine’s menu setting or in the printer Properties of the driver. 
(See  Toner Save  on page 2-6 or  Advanced tab in the...

Chapter 11
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All black
Clean the primary corona wire on the drum unit. (See  Cleaning the corona wire on 
page 11-24.)
If the print quality has not improved, install a new drum unit. (See  Replacing the 
drum unit (DR-2000)  on page 11-28.)
White Spots on black text and 
graphics at 78.5 mm 
intervals
Black Spots at 78.5 mm   intervals
Cleaning the drum unit
Dust, paper powder, glue, and so on may stick to the surface of the photosensitive 
drum (OPC) and cause black or white spots to appear on...

Troubleshooting and routine maintenance11 - 18
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Black toner marks across the page
Make sure that you use paper that meets our specifications. (See  About paper on 
page 1-9.)
If you use label sheets for laser printers, the glue from the sheets may sometimes 
stick to the OPC drum surface. Clean the drum unit. (See  Cleaning the corona wire 
on page 11-24.)
Do not use paper that has clips or staples because they will scratch the surface of 
the drum.
If the unpacked drum unit is in direct sunlight or...

Chapter 11
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Curl or wave
Check the paper type and quality. High temperatures and high humidity will cause 
paper to curl.
If you don’t use the machine very often, the paper may have been in the paper tray 
too long. Turn over the stack of paper in the paper tray. Also, fan the paper stack 
and then rotate the paper 180° in the paper tray.
Wrinkles or creases
Make sure that paper is loaded properly.
Check the paper type and quality. (See  About paper on page 1-9.)
Turn over the stack of paper in...

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11
Compatibility
If you are having difficulty sending or 
receiving a fax due to possible interference 
on the phone line, we recommend that you 
adjust the Equalization for compatibility to 
reduce the modem speed for fax operations.
1Press Menu/Set , 2, 0, 1.
2Press ▲ or ▼ to select Basic or 
Normal (or High*) (*MFC-7820N only).
Press  Menu/Set .
3Press Stop/Exit .
Note
■Basic reduces the modem speed to 9600 
bps. Unless interference is a recurring...

Chapter 11
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9Pack the drum unit and toner cartridge 
assembly, AC power cord and printed 
materials in the original carton as shown 
below:
0Close the carton and tape it shut.
Routine maintenance
Cleaning the outside of the 
machine
Clean the outside of the machine as 
follows:
1Pull the paper tray completely out of the 
machine.
CAUTION
The drum unit contains toner, so handle it 
carefully. If toner scatters and your hands 
or cloths get dirty, immediately wipe or 
wash it off with cold water....

Troubleshooting and routine maintenance11 - 22
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2Wipe the outside of the machine with a 
soft cloth to remove dust.
3Remove any paper that is in the paper 
tray.
4Wipe the inside and the outside of the 
paper tray with a soft cloth to remove 
dust.
5Re-load the paper and put the paper tray 
firmly back in the machine.
Cleaning the scanner glass
Turn off the machine’s power switch and lift 
the document cover. Clean the scanner glass 
and the white plastic surface underneath  the 
document cover with...

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Cleaning the laser scanner 
window
1Before you clean the inside of the 
machine, turn off the machine’s power 
switch. 
Unplug the telephone line cord first, and 
then unplug the power cord from the 
electrical socket.
2Open the front cover and pull out the 
drum unit and toner cartridge assembly.
3Gently clean the laser scanner window 
by wiping it with a clean soft dry lint-free 
cloth. Do not use isopropyl alcohol.
CAUTION
■Do  not use isopropyl alcohol to clean 
the laser scanner...

Troubleshooting and routine maintenance11 - 24
11
4Put the drum unit and toner cartridge 
assembly back into the machine.
5Close the front cover.
6Plug the machine’s power cord back into 
the electrical socket first, and then plug 
in the telephone line cord.
Turn on the machine’s power switch.
Cleaning the corona wire
We recommend placing the drum unit and 
toner cartridge assembly on a cloth or large 
disposable paper to avoid spilling and 
scattering toner.
1Open the front cover and pull out the...

Chapter 11
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Replacing the toner cartridge 
TN-2000
The toner cartridge can print  up to 2,500 
pages. When the toner cartridge is running 
low, the LCD shows 
Toner Low. Actual page 
count will vary depending on your average 
type of document (i.e., standard letter, 
detailed graphics).
Note
It is a good idea to keep a new toner cartridge 
ready for use when you see the 
Toner Low 
warning.
Discard the used toner cartridge according to 
local regulations, keeping it separate from 
domestic waste....