After changing toner there is a non-printed area about 1/8 inch wide clear across the page and this repeats about every 3 inches. Additional shaking of the cartridge does not help.

My guess would be the fuser. If the lines are consistent its either the fuser or bad toner cartridges.

Run the 1/2 print test.
Print a few pages that have failed previously and as the printer is printing open the cartridge cover(top cover).
Pull out the cartridge and look at the paper down below. If the page looks good, you probably need a new fuser. If the page is messed up you could have a bad transfer roller or another bad toner cartridge.

To determine if the vertical lines appearing on your printed documents are related to a printing or scanning issue, print a test page by pressing MENU, 4 (Printer), 2 (Print Options), 3(Test Print) and COLOR START.
If the vertical lines appear on the Test Print continue to Procedure A:Cleaning the Corona Wires Inside the Drum.
If the vertical lines do NOT appear on the Test Print continue to Procedure B: Cleaning the Scanner Glass.
Procedure A: Cleaning the Corona Wires Inside the Drum:
NOTE: Brother strongly recommends that customers do not use generic drumunits and/or toner cartridges, or refill their Brother toner cartridge. Each Brother laser printer is designed to work at pre-set temperatures that are matched exactly to each of our individual toner formulations. Each individual component is designed to work with the other to ensure quality and reliability. Using non-Brother supplies may affect the hardware performance, print quality and machine reliability. The Brotherlimited warranty does not apply to any problem that is caused by the useof unauthorized third party drum units, toner cartridges or toner.
A1. Power off the Brother machine using the power switch located on the right side of the machine.
A2. Press down on the front cover release lever and open the front coverby pulling it towards you.
A3. Hold the green handle of the drum unit (labeled 1). Lift the drum unit up and then pull it out until it stops.
NOTE: If you cannot pull the drum unit out, make sure that the front cover is fully open.
A4. Remove the toner cartridges one at a time, by holding the handle of the cartridge and lifting it up and out of the drum unit.
Note: We recommend you place the toner cartridge(s) on a clean, flat surface with a piece of disposable paper underneath it in case you accidentally spill or scatter toner.
A5. Lift the white plastic corona wire cover by lifting the tabs locatedon the right and left side of the cover.
A6. Clean the corona wire inside the drum unit by gently sliding the green tab from left to right several times.
Note: Be sure to return the tab to the home position. If you do not, printed pages may have a vertical stripe.
A7. Close the corona wire cover.
A8. Repeat Steps 5 through 7 to clean each of the remaining three coronawires.
A9. Reinstall the toner cartridge(s):
NOTE: Before reinstalling the toner cartridge, shake the toner cartridgeside to side.
Hold the handle of the toner cartridge and slide the toner cartridge into the drum unit. Make sure that you match the toner cartridge color to the same color label on the drum. Fold down the toner cartridge handle once the toner cartridge is in place. Repeat this for all the toner cartridges.
A10. Push the drum unit back into the machine until it clicks into place.
A11. Close the front door and power on the Brother machine.
A12. Print a test page by pressing Menu, 4 (Printer), 2 (Print Options),3(Test Print) and Color Start.
Procedure B: Cleaning the Scanner Glass
B1. For safety reasons, power the Brother machine Off using the power switch located on the right side of the machine.
B2. Lift the Document Cover and clean the following with a lint-free cloth moistened with a non-flammable glass cleaner:
a. Run your fingertip over the scanner glass of the flat bed to check for debris. If you feel debris, clean the entire glass area but concentrating in the area in which you felt the debris. (Caution! Do notpress down on the glass very hard.)
b. Run your fingertip over the scanner glass on the left to check for debris. If you feel debris, clean the entire glass area but concentrating in the area in which you felt the debris.
c. The white plastic pad located on the underside of the Document Cover
d. The white plastic pressure bar located to the left of the white plastic pad.
B3. Close the Document Cover.
B4. Test the machine by making a copy of a blank sheet of paper using the ADF (Automatic Document Feeder) and a copy using the Flat Bed.
a. To make a copy using the ADF, place the document face UP in the ADF, press the COPY mode key located below the LCD display and then COLOR START. If the problem continues,repeat Steps 2b and 2d at least 3 additional times.
b. To make a copy using the flat bed, lift the Document Cover of the flat bed, place the document face down on the scanner glass (make sure the ADF is empty) and close the Document Cover. Press the COPY mode key located below the LCD display and then COLOR START. If the problem continues, repeat Steps 2a and 2c at least 3 additional times.

Try an old toner cartridge if you have one. Does it do it when you use the copier function. Steven 805-520-3003

Take the toner cartridge out, shake it back and forth, and turn it around in a circle a few time. Put it back in the priter, and print. Order a new toner cartridge.

If this is an inkjet printer, ignore this response.

Remove the toner and wipe the small window that's above where the drum unit sits inside. That window gets covered with toner and makes light prints and blank areas.

Look inside where the drum goes, there's a thin window, about 1 inch wide, across the top of where the drum goes, a dry cloth will wipe off toner deposits.

We were having a lot of print quality problems, similar to what you describe. We replaced the drum and it worked fine.

To clear white vertical lines from printed documents follow the steps listed below:

NOTE: The use of non-Brother or generic toner may cause white vertical lines.

Brother strongly recommends that customers do not use generic drum units and/or toner cartridges, or refill their Brother toner cartridge. Each Brother laser printer is designed to work at pre-set temperatures that are matched exactly to each of our individual toner formulations. Each individual component is designed to work with the other to ensure quality and reliability. Using non-Brother supplies may affect the hardware performance, print quality and machine reliability.
The Brotherlimited warranty does not apply to any problem that is caused by the useof unauthorized third party drum units, toner cartridges or toner.

1. First, power OFF the unit for safety. The ON/OFF switch is located on the left, rear side of the unit.

2. Open the scanner cover by pulling the blue lever located below the control panel toward you and lifting the cover. Make sure the cover is completely open.

3. Remove the drum unit by holding each side of the drum by its handles and gently lifting the drum forward (toward) you.

4. Place the drum unit on a drop cloth or large piece of disposablepaper to avoid spilling and scattering the toner. Make sure thedirections and DR-250 stickers are facing you.

5. With the drum removed from the Brother machine, clean the laser glass. The laser glass is located inside the Brother machine where the drum was located. It is a piece of glass, about 1/2 inch wide and approximately 8 inches long, located on the bottom of the inside. Gently wipe the glass with a clean soft DRY cloth. DO NOT use isopropyl alcoholor any liquid to clean the glass.

6. Gently pull up on the mauve lever to turn the toner cartridge toward you until it stops. Remove the toner cartridge from the drum unit by gently sliding it out of the drum unit. ***Handle the toner cartridge carefully. If toner scatters on your hands or clothes, immediately wipe it off or wash it with cold water.

7. Gently rock the toner cartridge from side to side five or six times to distribute the toner evenly inside the cartridge. Then, reset the toner into the drum (be sure it clicks into place). Gently push on the mauve lever to turn the toner cartridge away from you until it stops.

8. With the DR-250 sticker facing you turn the drum upside down. There is a blue tab located on the right side. Slide the blue tab back and forth seven times to clean the corona wire. When finished, make sure the blue tab is locked to the right side of the drum.

9. Reset drum unit in Brother machine. Close the cover securely.

Print the help list to test the unit by pressing the REPORTS key located on the control panel and then (1) on the dial pad.

If the white vertical lines still continue, the drum unit will need to
be replaced.

If the purchase date of the original drum or replacement drum is less than 90 days (within the warranty of the drum), contact Brother Customer Service Center at 1-877-Brother (1-877-276-8437) . The center is open Monday-Friday, 9:00am to 7:00 pm EST, excluding holidays.

try a new toner cartridge

if it doesn't fix your problem then you willneed a new fuser
it is probably delaminated