Brother MFC 8420 User Manual
Have a look at the manual Brother MFC 8420 User Manual online for free. It’s possible to download the document as PDF or print. UserManuals.tech offer 331 Brother manuals and user’s guides for free. Share the user manual or guide on Facebook, Twitter or Google+.
TROUBLESHOOTING AND ROUTINE MAINTENANCE 22 - 19 White Spots on black text and graphics at 94 mm (3.7 in.) intervals Black Spots at 94 mm (3.7 in.) intervalsIf the problem is not solved after printing a few pages, the drum unit may have glue from label stock on the OPC drum surface. Clean the drum unit as follows: 1 Position the print sample in front of the drum unit, and find the exact position of the poor print. 2 Turn the drum unit gear by hand while looking at the surface of the OPC drum. Do not touch the photosensitive drum with your fingers. 3 When you have located the mark on the drum that matches the print sample, wipe the surface of the OPC drum with a cotton swab until the dust or paper powder on the surface comes off. Do not try to clean the surface of the photosensitive drum with a sharp object, such as a ball-point pen, and so on. The drum unit may be damaged. Put in a new drum unit. (See Re pl ac in g the drum unit on page 22-34.) Examples of poor print qualityRecommendation 94 mm (3.7 in.) 94 mm (3.7 in.) 94 mm (3.7 in.) 94 mm (3.7 in.) Photosensitive drum
22 - 20 TROUBLESHOOTING AND ROUTINE MAINTENANCE Black toner marks across the pageThe drum unit may be damaged. Put in a new drum unit. (See Replacing t h e d r um u ni t on page 22-34.) Make sure that you use paper that meets our specifications. (See About paper on page 2-1.) 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 drum unit on page 22-27.) 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 room light, the unit may be damaged. White lines across the pageMake sure that you use paper that meets our specifications. A rough surfaced paper or thick print media can cause the problem. Make sure that you select the appropriate media type in the printer driver. The problem may disappear by itself. Try printing multiple pages to clear this problem, especially if the printer has not been used for a long time. The drum unit may be damaged. Put in a new drum unit. (See Replacing t h e d r um u ni t on page 22-34.) Lines across the pageClean the inside of the printer and the primary corona wire in the drum unit. (See Cleaning the drum unit on page 22-27.) The drum unit may be damaged. Put in a new drum unit. (See Replacing t h e d r um u ni t on page 22-34.) Black lines down the page Printed pages have toner stains down the page.Clean the primary corona wire of the drum unit. Make sure the primary corona wire cleaner is at the home position ( ▲). The drum unit may be damaged. Install a new drum unit. (See Replacing t h e d r um u ni t on page 22-34.) The toner cartridge may be damaged. Put in a new toner cartridge. (See Replacing the toner cartridge on page 22-28.) Make sure that a torn piece of paper is not inside the printer covering the scanner window. The fixing unit may be smudged. Call Customer Service. White lines down the pageYou may clear the problem by wiping the scanner window with a soft cloth. (See Cleaning the printer on page 22-26.) The toner cartridge may be damaged. Put in a new toner cartridge. (See Replacing the toner cartridge on page 22-28.) Page skewedMake sure the paper or other print media is loaded properly in the paper tray and that the guides are not too tight or too loose against the paper stack. Set the paper guides correctly. If you are using the manual feed tray (or the multi-purpose tray). (See How to load paper on page 2-5.) The paper tray may be too full. Check the paper type and quality. (See About paper on page 2-1.) Curl or waveCheck the paper type and quality. High temperatures and high humidity will cause paper to curl. If you don’t use the printer very often, the paper may have been in the paper tray too long. Turn over the stack of paper in the paper tray. Also, try fanning the paper stack and then rotating the paper 180° in the paper tray. Try printing using the straight-through output path. (See How to load paper on page 2-5.) Examples of poor print qu a lit yRecommendation ABCDEFGH abcdefghijk ABCD abcde 01234 ABCDEFGH abcdefghijk ABCD abcde 01234 ABCDEFGH abcdefghijk ABCD abcde 01234 ABCDEFGH abcdefghijk ABCD abcde 01234 ABCDEFGH abcdefghijk ABCD abcde 01234 A B C D E F G H a b c d e f g h i j k ABCD abcde 01234
TROUBLESHOOTING AND ROUTINE MAINTENANCE 22 - 21 Wrinkles or creasesMake sure that paper is loaded properly. Check the paper type and quality. (See About paper on page 2-1.) Try printing using the straight-through output path. (See How to load paper on page 2-5.) Turn over the stack of paper in the tray or try rotating the paper 180° in the input tray. The drum unit is a consumable item and it is necessary to replace it periodically. Examples of poor print qualityRecommendation B DEFGH abc efghijk ACD bcde 134
22 - 22 TROUBLESHOOTING AND ROUTINE MAINTENANCE Packing and shipping the MFC Whenever you transport the MFC, use the packing materials that came with your machine. If you do not pack t he MFC correctly, you may void your warranty. 1Turn t he MFC power swit ch off. 2Unplug the MFC from the telephone wall jack. 3Unplug the MFC from the AC outlet. Lock the Scanner Lock 4Push the Scanner Lock Lever down to lock the scanner. This lever is located on the left of the scanner glass. Caution Damage caused to your MFC by failure to lock the scanner before moving and shipping may void your warranty. 5Open the front cover. Scanner Lock Lever
TROUBLESHOOTING AND ROUTINE MAINTENANCE 22 - 23 6Remove the drum unit and t oner cartridge assembly. Leave the t oner cartridge installed in the drum unit. 7Place the drum unit and toner cartridge assembly into the plastic bag and seal the bag. 8Close the front cover. Fold down t he face-down output tray flap. Remove t he telephone line cord. 9Wrap the MFC in the plastic bag and place it in t he original carton with the original packing material.
22 - 24 TROUBLESHOOTING AND ROUTINE MAINTENANCE 10Pack the drum unit and t oner cartridge assembly, telephone line cord, AC cord and printed materials in the original carton as shown below: 11Close t he carton and tape it shut. If you are returning the MFC to Brother as part of the Exchange Service, pack only the MFC. Keep all separate parts to use with your ‘Exchange’ machine.
TROUBLESHOOTING AND ROUTINE MAINTENANCE 22 - 25 Routine maintenance Cleaning the scanner Turn the MFC power switch off and lift the document cover. Clean the scanner glass and glass strip with dry clot h and the white film with isopropyl alcohol on a lint free cloth. If t he screen still displays a scanner error, call Brother Customer Service for assistance at 1-800-284-4329 (in USA) or 1-877-BROTHER (in Canada). White Film Document Cover Glass strip White film
22 - 26 TROUBLESHOOTING AND ROUTINE MAINTENANCE Cleaning the printer Caution ■Do not use isopropyl alcohol to remove dirt from the cont rol panel. It may crack the panel. ■Do not use isopropyl alcohol to clean the laser scanner window. ■Do not touch t he scanner window with your finger. ■The drum unit contains toner, so handle it carefully. If toner scatters and your hands or clothes get dirty, immediately wipe or wash it off with cold water. 1Turn t he MFC power swit ch off and open the front cover. 2Remove the drum unit and toner cartridge assembly. WARNING Just af ter you have used the MFC, some internal part s of the machine are extremely HOT! When you open the front cover of the MFC, never touch the shaded parts shown in the diagram below. 3Gently clean the scanner window by wiping it with a clean soft dry cloth. Do not use isoproply alcohol. Front view HOT! Laser Scanner Window
TROUBLESHOOTING AND ROUTINE MAINTENANCE 22 - 27 Cleaning the drum unit We recommend placing the drum unit and toner cart ridge assembly on a cloth or large disposable paper to avoid spilling and scattering toner. 1Clean the primary corona wire inside the drum unit by gent ly sliding the blue tab from right to left several t imes. 2Return the blue tab and snap it into the Home position (▼). Caution If t he blue tab is not at Home posit ion (▼), printed pages may have vertical stripes. 3Reinstall the drum unit and toner cartridge assembly into the MFC. (See Replacing the drum unit on page 22-34.) 4Close the f ront cover. 5Plug in the power cord first, then the telephone cord. Corona Wire Tab Home Position(▼)
22 - 28 TROUBLESHOOTING AND ROUTINE MAINTENANCE Replacing the toner cartridge The MFC can print up to 6,500 pages using a high yield toner cartridge. When the toner cartridge is running low, the LCD shows Toner Low. The MFC is supplied with a standard toner cartridge that must be replaced after approximately 3,300 pages. Actual page count will vary depending on your average t ype of original (i.e., standard let ter, detailed graphics). Discard the used toner cart ridge according to local regulations, keeping it separate from domestic waste. Be sure to seal the toner cartridge tightly so toner powder does not spill out of the cartridge. If you have questions, call your local waste disposal office. We recommend that you clean the MFC when you replace the toner cartridge. It is a good idea to keep a new toner cartridge ready for use when you see the Toner Low warning.