Brother Mfc 8370dn User Manual

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Improving the print qualityC
Examples of poor print 
qualityRecommendation
 
White lines across the page„Make sure that you use paper that meets our specifications. A rough 
surfaced paper or thick print media can cause the problem. (See 
Acceptable paper and other print media on page 14.)
„Make sure that you choose the appropriate media type in the printer 
driver or in the machine’s Paper Type menu setting. (See Acceptable 
paper and other print media on page 14 and Basic tab in the Software...

Troubleshooting and routine maintenance
121
C
 
Page skewed„Make sure that the paper or other print media is loaded correctly in 
the paper tray and that the guides are not too tight or too loose 
against the paper stack.
„Set the paper guides correctly. (See Loading paper in the standard 
paper tray on page 10.)
„If you are using the MP tray, see Loading paper in the multi-purpose 
tray (MP tray) on page 11.
„The paper tray may be too full.
„Check the paper type and quality. (See Acceptable paper and...

122
 
Envelope creases„Make sure that the envelope levers inside the back cover are pulled 
down when you print the envelopes.
 
 
Curled or wavy„Check the paper type and quality. High temperatures and high 
humidity will cause paper to curl.
„If you do not use the machine 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.
Examples of poor print 
qualityRecommendation...

Troubleshooting and routine maintenance
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C
 
Curled„Turn the paper over in the paper tray, and print again. (excluding 
Letterhead paper) If the problem remains, slide the Anti-Curl Switch 
as follows:
1 Open the back cover.
 
2 With one hand, use the tab (1) to lift the roller assembly, then use 
your other hand to slide the Anti-Curl Switch (2) in the direction of 
the arrow.
 
3 Close the back cover.
„Lift up the Output Tray Support Flap (1).
 
„Choose Reduce Paper Curl mode in the printer driver....

124
 
White Spots on black text 
and graphics at 94 mm 
intervals
 
Black Spots at 94 mm 
intervals„Make ten copies of a blank, white sheet of paper. (See Making 
multiple copies on page 78.) If the problem is not solved, the drum 
unit may have glue from a label stuck on the OPC drum surface. 
Clean the drum unit. (See Cleaning the drum unit on page 146.)
„The drum unit may be damaged. Put in a new drum. (See Replacing 
the drum unit on page 153.)
 
Faint„Check the machine’s environment. Conditions such...

Troubleshooting and routine maintenance
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C
 
All black„Clean the corona wire inside the drum unit by sliding the blue tab. Be 
sure to return the blue tab to the home position (a). (See Cleaning the 
corona wire on page 145.)
„The drum unit may be damaged. Put in a new drum unit. (See 
Replacing the drum unit on page 153.)
„The fuser unit may be contaminated. Call your Brother dealer for 
service.
 
Black toner marks across the 
page„Make sure that you use paper that meets our specifications. (See...

126
 
Poor fixing„Open the back cover and make sure that the two blue levers on the 
left and right hand sides are in the up position.
 
„Choose Improve Toner Fixing mode in the printer driver. (See Other 
Print Options (For Windows®) or Print Settings (For Macintosh) in the 
Software User’s Guide on the CD-ROM.)
If this selection does not provide enough improvement, choose 
Thicker Paper in Media Type settings.
Examples of poor print 
qualityRecommendation
ABCDEFGH
abcdefghijk
ABCD
abcde
01234
 

Troubleshooting and routine maintenance
127
C
Setting Dial Tone detectionC
When you send a fax automatically, by 
default your machine will wait for a fixed 
amount of time before it starts to dial the 
number. By changing the Dial Tone setting to 
Detection you can make your machine dial 
as soon as it detects a dial tone. This setting 
can save a small amount of time when 
sending a fax to many different numbers. If 
you change the setting and start having 
problems with dialling you should change...

128
Error and maintenance messagesC
As with any sophisticated office product, errors may occur and consumable items may need to be 
replaced. If this happens, your machine identifies the error or required routine maintenance and 
shows the appropriate message. The most common error and maintenance messages are shown 
below.
You can clear most errors and perform routine maintenance messages by yourself. If you need 
more help, the Brother Solutions Center offers the latest FAQs and troubleshooting tips....

Troubleshooting and routine maintenance
129
C
Cooling Down
Wait for a whileThe temperature of the drum unit 
or toner cartridge is too hot. The 
machine will pause its current 
print job and go into cooling down 
mode. During the cooling down 
mode, you will hear the cooling 
fan running while the LCD shows 
Cooling Down, and 
Wait for a while.Make sure that you can hear the fan in the 
machine spinning and that the exhaust outlet 
is not blocked by something.
If the fan is spinning, remove any obstacles...