Brother MFC 8420 User Manual

TROUBLESHOOTING AND ROUTINE MAINTENANCE   22 - 9
WARNING
After you have just used the MFC, some internal parts of the MFC 
are extremely HOT! Wait for the MFC t o cool down before you touch 
the internal parts of the MFC.
6O pen the jam clear cover (fuser cover). Pull the jammed paper 
out of the fuser unit .
7Close the jam clear cover. Close the back out put tray.
HOT!
Back view
Jam Clear Cover
(Fuser Cover)
 

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8Push the lock lever down and take the toner cartridge out of the 
drum unit  assembly. Take out the jammed paper if there is any 
inside the drum unit.
9Put the drum unit assembly back in the MFC.
10Put the paper tray in the MFC.
11Close the front cover.
 

TROUBLESHOOTING AND ROUTINE MAINTENANCE   22 - 11
Paper is jammed in the duplex tray (For MFC-8820D and 
MFC-8820DN)
1Pull the duplex tray and paper tray out of the MFC.
2Pull the jammed paper out of t he MFC.
3Put the duplex tray and paper tray back into the MFC.
 

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■The Jam Duplex message appears if you remove a sheet 
of paper from the Face Down Output Tray after only one side 
has printed.
■If t he Paper Adjustment Lever for Duplex Printing is not set 
correctly for the paper size, paper jams may occur and the 
printing will be out of position on the page.  (See To use 
Automatic Duplexing for fax, copy and print operations  (For 
MFC-8820D and MFC-8820DN) on page 2-10.)
 

TROUBLESHOOTING AND ROUTINE MAINTENANCE   22 - 13
If you are having difficulty with your MFC
If you think there is a problem with the way your faxes look, make a 
copy first. If the copy looks good, the problem is probably not your 
MFC. Check the chart below and follow t he troubleshooting t ips.
DIFFICULTYSUGGESTIONS
Printing or Receiving Faxes
Condensed print  and 
horizontal streaks or the top 
and bottom of sentences are 
cut off.
I f  y ou r c op y l oo ks  go od,  yo u pr ob ab l y ha d a ba d c...

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Vertical black lines when 
sending.If the copy you made shows the same problem, your scanner is dirty. 
(See Cleaning the scanner on page 22-25.)
Handling Incoming C alls
MFC ‘Hears’ Voice as CNG 
Tone.If your MFC is set to Easy Receive ON, it is more sensitive to sounds. 
Your MFC may mistakenly interpret certain voices or music on the line 
as a calling fax machine and respond with fax receiving tones. 
Deactivate the fax by pressing Stop /Exit. Try...

TROUBLESHOOTING AND ROUTINE MAINTENANCE   22 - 15
Printer Difficulties
The MFC does not print. Check the following:
 The MFC is plugged in and the power switch turned On. (See the 
Quick Setup Guide on page 7.) 
 The toner cartridge and drum unit are installed properly. (See 
Replacing the  drum unit on page 22-34.)
 The interface cable is securely connected between the MFC and 
computer. (See the Quick Setup Guide.) 
 Check to see if LCD is showing an error message. (See Error 
messages on page...

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Software Difficulties
Cannot perform ‘2 in 1 or 4 in 1’ 
printing.Check that the paper size setting in the application and in the printer 
driver are the same.
Cannot print when using 
Adobe Illustrator.Try  to reduce  the print resolution.
When using ATM fonts, some 
characters are missing or 
some characters are printed in 
their place.If you are using Windows
® 95/98/98SE/Me, select ‘Printer Settings’  from 
the ‘Start’ menu. Select the properties of...

TROUBLESHOOTING AND ROUTINE MAINTENANCE   22 - 17
Print Quality Difficulties
Printed pages are curled. Thin or thick paper below the standard can cause this problem. Make 
sure you select the Paper Type that suits the media type you use. (See 
Setting the Paper Type on page 4-5 and Media Type on page 12-4.)
Printed  pages  are  smeared. The  Paper Type  setting may be incorrect  for the type of print media you 
are using—OR—The print media may be too thick or have a rough 
surface. (See Setting the Paper...

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Improving the print quality
This section provides information on the following topics:
Examples of poor print 
qu a lit yRecommendation
FaintCheck the printer’s environment. Conditions such as humidity, high 
temperatures, and so on may cause this print fault. (See Choosing a 
location on page ix .)
If the whole page is too light, Toner Save mode may be on. Turn off 
To ne r  Sa ve mode in the printer Properties tab of the driver.
—OR—
If your MFC is not...