Brother MFC 9420CN User Manual

							Chapter C
C - 16
Improving the print quality
If you are having problems with print quality, please do a test print first (Menu/Set, 4, 2, 3).
If the problem appears on the printout, then match it to one of the examples below and follow the 
recommendation. If the problem does not appear on the test print, please check driver settings 
and the interface cables as the problem may not lie with the machine.
Examples of poor print qualityRecommendation
White lines or bands or ribbing 
across the page■Check that the machine is on a solid level surface.
■Check that the back cover is closed properly.
■Check that the toner cartridges are installed properly.
■Shake the toner cartridges gently.
■Check that the transfer roller is installed properly.
■Replace the transfer roller. (See Replacing the transfer roller on page C-39.)
Colors are light or unclear on the 
whole page■Check that the recommended paper was used. (See Recommended paper on 
page 2-1.)
■Change the paper to freshly unpacked paper, and then check that the problem 
is solved.
■Check that the back cover is closed properly.
■Shake the toner cartridges gently.
■Clean the laser glass. (See Cleaning the laser glass on page C-24.)
■Turn off Toner Save. (See Toner Save on page 3-7.)
White streaks or bands down the 
pageClean the laser glass. (See Cleaning the laser glass on page C-24.)
Identify the missing color and replace that toner cartridge. (See Replacing a toner 
cartridge on page C-29.)
The toner has probably reached the end of its life.
However, when you see a white vertical line on the toner roller, try the following 
procedure.
■Cut a sheet approx. 1.97 in. x 1.97 in. (50 mm x 50 mm) out of a transparency 
film. 
■Insert the film about 2.54 in. (10 mm) into the gap between the toner roller and 
the blade.
■Slide the film and pull it out as shown below.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
 
						

							Troubleshooting and routine maintenance
C - 17
C
Colored streaks or bands down the 
page■Identify the color and replace that toner cartridge. (See Replacing a toner 
cartridge on page C-29.)
■Replace the OPC belt cartridge. (See Replacing the OPC belt cartridge 
(OP-4CL) on page C-33.)
Colored lines across the page■Clean the registration roller, the paper pick-up roller, the transfer roller guide 
and the exit roller. (See Cleaning to prevent paper jams on page C-22.)
■If the problem continues, identify the color and replace that toner cartridge. 
(See Replacing a toner cartridge on page C-29.)
White spots or hollow print■Change the paper to freshly unpacked paper.
■Check that the recommended paper was used. (See Recommended paper on 
page 2-1.)
■Check that the room temperature is higher than 50 °F (10 °C)
Completely blank or some colors 
are missing■Check that the back cover is closed properly.
■Check that the front cover is closed properly.
■Identify the missing color and check that the toner cartridge is installed 
properly. 
■Replace the toner cartridge. (See Replacing a toner cartridge on page C-29.)
■Replace the OPC belt cartridge. (See Replacing the OPC belt cartridge 
(OP-4CL) on page C-33.)
Colored spots or Toner stain■Identify the color causing the problem and replace the toner cartridge. 
(See Replacing a toner cartridge on page C-29.)
Examples of poor print qualityRecommendation
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
 
						

							Chapter C
C - 18
Toner scatter or toner stain■Identify the color causing the problem and replace that toner cartridge. 
(See Replacing a toner cartridge on page C-29.)
■Replace the OPC belt cartridge. (See Replacing the OPC belt cartridge 
(OP-4CL) on page C-33.)
The color of your printouts is not 
what you expected■Check that the toner cartridges are installed properly.
■Check that the toner cartridges are not empty. (See Toner empty message on 
page C-29.)
■Perform the calibration. (Menu/Set, 4, 4)
■Adjust the color by using the custom setting in the driver. Colors the machine 
can print and colors you see on a monitor are different. The machine may not 
be able to reproduce the colors on your monitor.
■Check to make sure the recommended paper was used. (See Recommended 
paper on page 2-1.)
All one color Replace the OPC belt cartridge. (See Replacing the OPC belt cartridge (OP-4CL) 
on page C-33.)
Shade on the transparency■Change to the recommended type of transparency, and then check that the 
problem is solved.
■Check that the media type mode is selected properly.
Color mis-registration■Check that the OPC belt cartridge is installed properly.
■Check that the cleaning roller is installed properly.
■Replace the OPC belt cartridge. (See Replacing the OPC belt cartridge 
(OP-4CL) on page C-33.)
■Replace the cleaning roller. (See Replacing the transfer belt cleaner on 
page C-37.)
Uneven density appears 
periodically across the page■Check that the toner cartridges are installed properly.
■Check that the OPC belt cartridge is installed properly.
■Check that the cleaning roller is installed properly.
■Check that the back cover is closed properly.
■Check that the fusing unit is installed properly.
■Replace the OPC belt cartridge. (See Replacing the OPC belt cartridge 
(OP-4CL) on page C-33.)
Examples of poor print qualityRecommendation
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
 
						

							Troubleshooting and routine maintenance
C - 19
C
Missing image at edge■Check that the toner cartridges are installed properly.
■Check that the OPC belt cartridge is installed properly.
■Identify the color causing the problem and replace the toner cartridge. 
(See Replacing a toner cartridge on page C-29.)
■Replace the OPC belt cartridge. (See Replacing the OPC belt cartridge 
(OP-4CL) on page C-33.)
Wrinkle■Change to a recommended type of paper, and then check that the problem is 
solved. (See Recommended paper on page 2-1.)
■Check that the back cover is closed properly.
■Check that the transfer roller is installed properly.
■Check that the fusing unit is installed properly.
■Replace the fusing unit. (See Replacing the fusing unit on page C-35.)
Mixed color image■Check that the front cover is closed properly.
■Check that the toner cartridges are installed properly.
■Check that the transfer roller is installed properly.
■Replace the toner cartridges. (See Replacing a toner cartridge on page C-29.)
Insufficient  gloss Check that the recommended paper is being used. (See Recommended paper on 
page 2-1.)
Offset image Check that the recommended paper is being used. (See Recommended paper on 
page 2-1.)
Poor fixing■Check that the recommended paper is used. (See Recommended paper on 
page 2-1.)
■Check that the media type mode is selected properly.
■Check that the release lever of the fusing unit is set properly.
■Replace the fusing unit. (See Replacing the fusing unit on page C-35.)
Poor fixing when printed on thick 
paperSet the machine to thick paper mode through the control panel or the printer driver. 
(See the Software User’s Guide on the CD-ROM.)
Examples of poor print qualityRecommendation
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
ABCDEFGHIJKLMNOPQRSTUVWXYZ. 0123456789. abcdefghijklmnopqrstuvwxyz.
 
						

							Chapter C
C - 20
Setting Dial Tone Detection
Setting the dial tone to Detection will 
shorten the dial tone detect pause.
1Press Menu/Set, 0, 5.
2Press ▲ or ▼ to select Detection or 
No Detection.
Press Menu/Set.
3Press Stop/Exit.
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.
Press Menu/Set.
3Press Stop/Exit.
Note
■Basic reduces the modem speed to 9600 
bps. Unless interference is a recurring 
problem on your phone line, you may 
prefer to use it only when needed.
■Normal sets the modem speed at 14400 
bps.
■High sets the modem speed at 33600 bps 
■When you change the Compatibility to 
Basic, the ECM feature is not available. 
Routine maintenance
We recommend cleaning the following parts 
of the machine every 20,000 printed pages or 
every 12 months:
■Paper guides of the paper tray
■Registration roller
■Paper pick-up roller
■Transfer roller unit
■Transfer roller guide
■Exit roller
■Laser unit
■Laser glass
Initial Setup
5.Dial Tone
Miscellaneous
1.Compatibility
CAUTION
If toner scatters and your hands or clothes 
get dirty, immediately wipe or wash it off 
with cold water.
 
						

							Troubleshooting and routine maintenance
C - 21
C Cleaning the outside of the 
machine
Clean the outside of the machine as 
follows:
1Pull the paper tray completely out of the 
machine.
2Wipe the outside of the machine with a 
soft cloth to remove dust.
3Remove anything that is stuck inside 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.
CAUTION
■Use neutral detergents. Cleaning with 
volatile liquids such as thinner or 
benzine will damage the outside 
surface of the machine.
■Do not use cleaning materials that 
contain ammonia.
■Do not use isopropyl alcohol to remove 
dirt from the control panel. It may crack 
the panel.
 
						

							Chapter C
C - 22
Cleaning the scanner glass
Lift the document cover. Clean the scanner 
glass and white plastic above it with isopropyl 
alcohol on a soft lint-free cloth.
In the ADF unit, clean the white plastic bar 
and the scanner glass strip under it with 
isopropyl alcohol on a lint-free cloth.
Cleaning to prevent paper 
jams
When you clean the inside of the machine, 
pay attention to the following:
White Plastic
Scanner 
glass
Document 
Cover
Glass Strip
White 
Plastic Bar
WARNING
■The fusing unit and the parts around it 
are hot! Never touch the shaded areas 
shown below.
■Be careful not to inhale the toner.
CAUTION
■When you clean parts inside the 
machine, use a clean, dry soft, lint-free 
cloth. Do not use Isopropyl alcohol.
■If your clothes are smeared with toner, 
wipe off the toner with a dry cloth. 
Immediately wash your clothes in cold 
water to avoid stains.
■Never touch or clean the transfer roller 
because print quality may be adversely 
affected.
 
						

							Troubleshooting and routine maintenance
C - 23
C
1Turn off the machine’s power switch. 
Unplug the telephone line cord first, and 
then unplug the power cord from the AC 
power outlet. Open the back cover of the 
machine.
2Clean the registration roller and the 
paper pick-up roller with a dry soft, 
lint-free cloth to prevent paper jams.
3Clean the transfer roller unit and the 
transfer roller guide with a dry soft, 
lint-free cloth to prevent paper jams.
WARNING
■Be careful you do not break the 
actuator while cleaning the registration 
roller and paper pick-up roller.
■Make sure you do not put too much 
pressure on the registration roller and 
paper pick-up roller. This could 
damage them and cause poor print 
quality.
 
						

							Chapter C
C - 24
4Clean the exit roller. This will help to 
prevent paper jams at the paper exit and 
dirt from appearing on your printouts.
5Close the back cover.
6Plug the machine’s power cord back into 
the AC power outlet first, and then plug 
in the telephone line cord. Turn on the 
machine’s power switch.
Cleaning the laser glass
1Turn off the machine’s power switch. 
Unplug the telephone line cord first, and 
then unplug the power cord from the AC 
power outlet.
2Open the scanner unit.
3Open the inside cover so that it latches 
under the scanner unit.
4To release the lock, push the green belt 
cartridge lock levers that are on both 
sides inwards.
5Remove the OPC belt cartridge from the 
machine.
 
						

							Troubleshooting and routine maintenance
C - 25
C
6Place the OPC belt cartridge on a flat 
surface and cover the shiny green OPC 
belt with a piece of paper to prevent 
exposing it to light.
7Open the front cover of the machine.
8Take all the toner cartridges out of the 
machine.
9Clean the surface of the laser unit with a 
dry soft, lint-free cloth.
0Open the laser glass cover.
AClean the surface of the laser glass with 
a dry soft, lint-free cloth.
BClose the laser glass cover.
CPut all the toner cartridges and the OPC 
belt cartridge back in the machine. Do 
not try to push or lock the new toner 
cartridge in. It must rest loosely in the 
guide rails.
DClose the front cover and the inside 
cover, and then close the scanner unit.
EPlug the machine’s power cord back into 
the AC power outlet first, and then plug 
in the telephone line cord. Turn on the 
machine’s power switch.
CAUTION
■Do not touch the OPC belt surface with 
your hands.
■Do not expose the OPC belt cartridge 
to bright room light or sunlight (a light 
source of 74.3 footcandles or 800 lux) 
for more than two minutes to avoid 
damaging the belt.
WARNING
Do not use volatile liquids such as thinner 
or benzene for cleaning the laser glass. 
This might cause poor print quality.