A black line on the back, down the center of a printed sheet

Sir/Madam

If your printed pages have a horizontal line in the text or graphics (as shown in the illustration below) or blank text, some of the nozzles may be clogged and need to be cleaned

Go to Section 2 for instructions on how to print the Alignment Check sheet and adjust the print alignment.

Section 1: Checking the print quality and cleaning the print head

1. Print a Print Quality Check Sheet.
   
   
   1. Press Menu.
   2. Press the UP OR DOWN ARROW key or the dial pad to choose Ink Management and press OK.
   3. Press the UP OR DOWN ARROW key or the dial pad to choose Test Print and press OK.
   4. Press the UP OR DOWN ARROW key or the dial pad to choose Print Quality/Alignment and pressOK.
   5. Press Color (Colour) Start. The machine begins printing the Print Quality Check Sheet.
2. Closely examine the Print Quality Check Sheet. Each of the four colors is represented by a slanted square pattern made up of individual blocks. The colors should appear in the following order from left to right: Black - Yellow - Cyan - Magenta.
3. Compare the print quality of the Check Sheet you just printed with the three examples listed below:
   
   (A) One or more complete blocks of colors are missing:

(B) Most of the short diagonal lines are missing from one or more color blocks:




(C)Some parts of the short diagonal lines are missing from one or more color blocks:

1. The display will then ask you if the print quality is OK for black. Press the DOWN ARROW key or 2 to choose Nofor black with the problem.
2. The display will then ask you if the print quality is OK for Color. Press the DOWN ARROW key or 2 to chooseNo for color with the problem.
3. The display will then show Start Cleaning? Yes No.
   Press the UP ARROW key or 1 to choose Yes and the machine will start cleaning the color ink cartridges.
4. When the machine completes cleaning the print head, press Color (Colour) Start. Another Print Quality Check Sheet will print.
5. Repeat the cleaning and the quality check process following the Step 4-7.
6. Compare the second or third Print Quality Check Sheet with the first one you printed in step1:

9. Compare the second or third Print Quality Check Sheet with the first one you printed in step1:

• If the print quality on the first Check Sheet matched Example (A) or (B) and you do not see any improvement on the second or third Check Sheet, please contact Brother Customer Service from "Contact Us."

• If the print quality on the first Check Sheet matched Example (A) or (B) and you see some improvement on the second or third Check Sheet but it's not perfect, repeat the cleaning and the quality check process three more times (totally five times). If you do not see any further improvement after that, please contact Brother Customer Service from "Contact Us."

• If the print quality on the first Check Sheet matched Example (C) and you do not see any improvement on the second or third Check Sheet, repeat the cleaning and the quality check process three more times (totally five times). If you still do not see any improvement, please contact Brother Customer Service from "Contact Us."

10. Press Stop/Exit.

Section 2: Checking the Print Alignment

1. Press Menu.
2. Press the UP OR DOWN ARROW key or the dial pad to choose Ink Management and press OK.
3. Press the UP OR DOWN ARROW key or the dial pad to choose Test Print and press OK.
4. Press the UP OR DOWN ARROW key or the dial pad to choose Print Quality/Alignment and press OK.
5. Press Black (Mono) Start or Color (Colour) Start. The machine begins printing the Alignment Check Sheet.
6. By reviewing this Check Sheet, you can determine if the alignment needs adjustment.
7. Examine the 600 dpi and 1200 dpi test prints on the Alignment Check Sheet. If the number 5 sample of both the 600 dpi and 1200 dpi most closely matches the 0 sample, press the UP ARROW key or 1 to choose Yes.
   If one of the other samples is a better match for the 0 sample, press the DOWN ARROW key to choose No. The display will then prompt you to choose the sample that most closely matches the 0 sample for 600 dpi and then 1200 dpi.
8. Press Stop/Exit.

If the print quality continues to be poor, go to Section 1 to clean the print head.


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Try cleaning the charge wire. Move the lime green plastic handle from one side of the image unit to the other in the groove. If this doesn't work you'll need a new image unit.$$$$$. note: Make sure green handle is moved completely to the right when finished or black line will occur.

If the line is on the back, you need to have the machine cleaned, absorbers replaced and a mylar sheet installed so that doesn't happen again. Ink thats supposed to go to the absorber is coming back up on the rollers.

Thats because the ink is overflowing the ink absorber and coming up thru the bottom of the machine. You need a shop to replace the absorbers and install a mylar shield so that doesn't happen again.

Clean the nozzles, align the print heads, turn it off for about an hour. You may need to do this twice, but it works for me.

Try this:
Checking the print quality:

1. Press the Ink or Ink Management key on the control panel.
2. Press the up or down navigation key to select TEST PRINT and press Menu/Set or Set.
3. Press the up or down navigation key to select PRINT QUALITY and press Menu/Set or Set.
4. Press Color (Colour) Start. The MFC/DCP begins printing the Print Quality Test Sheet.
5. By reviewing this Test Sheet, you can determine if the print quality needs improvement.
6. Closely examine the print quality of the four color blocks that are formed by short diagonal lines on the Test Sheet.
   If all lines are clear and visible, press 1 (YES) and press Stop/Exit.
   If you can see missing short lines, press 2 (NO) and go to Step 7.
7. The display will then ask you if the print quality is OK for black and three colors. Press 2 (NO) for black or three colors with the problem.
8. The display will then show START CLEANING? 1.YES 2. NO.
   Press 1 (YES) and the MFC will start cleaning the color ink cartridges.
9. After the cleaning is finished, press Color (Colour) Start. The MFC/DCP will print another Print Quality Test Sheet.
10. If you can see missing short lines in any of the four color blocks press 2 (NO) and repeat the quality check and cleaning process. Repeat this procedure at least 5 times if print quality remains a problem. If short lines are still missing after the fifth cleaning and test print, replace the necessary ink cartridges. If the print quality of the 4 color blocks is OK, press 1 (YES).

Setting the Alignment:

1. Press the Ink or Ink Management key on the control panel.
2. Press the up or down navigation key to select TEST PRINT and press Menu/Set or Set.
3. Press the up or down navigation key to select ALIGNMENT and press Menu/Set or Set.
4. Press Black (Mono) Start or Color (Colour) Start. The MFC/DCP begins printing the Alignment Check Sheet.
5. By reviewing this Test Sheet, you can determine if the alignment needs adjustment.
6. Examine the 600 DPI and 1200 DPI test prints on the Alignment Check Sheet. If the number 5 sample of both the 600 DPI and 1200 DPI most closely matches the 0 sample, press 1 (YES).
   If one of the other samples is a better match for the 0 sample, press 2 (NO). The display will then prompt you to select the sample that most closely matches the 0 sample for 600 DPI and then 1200 DPI.
7. Press Stop/Exit.
   If I could be of further assistance, let me know. If this helps or solves the issue, please RATE it.
   Thanks, Joe
   

I’m happy to assist further over the phone at https://www.6ya.com/expert/joe_8b8c2cd6ce148309

Is there any debris under the printhead nozzle plate?

Check if the charge corona cleaner is pushed all the way to the end. If not, it will leave a black bar on all images.

Is the paper you are using a bond paper and a little heavy. The line is most likely comming from the fusing ass'y. Are you running it LTR size? Try runing it LTR-R size. It will not put as much fores on the fuser and it will run a little slower. Also try the by-pass. Or try to run some Blank White pages though it to clean the fusing ass'y. You also may need to rebiuld or replace the fusing ass'y.

REPLACE THE PHOTOCONDUCTER DRUM OR CLEANINGBLADE ASSY MOST LIKELEY JUST NEEDS NEW CLEANING BLADE