Black stains on the printed sheet

what color is the stain? mite need a need a new transfer belt or fusing unit

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/normanj_7893313f0751935f

Ran into this problem myself on a few inkjet models. Check to ensure you've programmed the unit for the type of paper (matte, photo, glossy, etc.) and that your paper matches your machine (most inkjets won't print correctly on laser photo paper). If those are OK, try cleaning your rollers - many newer units have an auto-clean setting. If that doesn't work try this: Unplug your printer. Turning it off is NOT the same thing since many units have a form of stand-by to decrease warm-up time, much like TVs. Take an old, soft T-shirt or other lintless absorbent cloth & dampen it slightly. Hopefully the cartridge holders are off to the side so you can see where the paper feeds through. Gently rub the rollers, changing areas of cloth as they become ink-soaked until they're clean. To check if clean: turn unit back on & put a clean sheet of paper on the glass to copy. I use stick glue (for kids) to put 2 regular pieces of paper together (mimics thickness of photo paper) & use this for the machine to print out my (hopefully) blank page.

Oh, and I wear vinyl gloves to keep my hands from getting stained anytime I work with printer ink. (My doc always gives me a few pair free whenever I come in). Good luck!

Liquid in the washer is better since sheets in the dryer are prone to leaving stains (read back of package about stain warning on every box of softener sheets i have ever seen) also the sheets leave a build up on the thermostats and moisture sensor

While the liquid in the washer softens the clothes and has no build up or staining issues such as the sheets

How is the printer printing black and yellow color? Is it a smudge?

When I print, the pages are smudged with ink. What should I do?
Description: - If smudged stains appear at the top center of the printed page:

• Make sure the paper is not too thick or curled.
  Also, verify that the appropriate paper is being used and that the paper type set in the machine matches the media used.
• Make sure the paper is not curled when you print on the back side of the paper with the Print Odd Pages and Print Even Pages settings.

- If smudged stains appear at the right or left corner of the printed page:

• Make sure the paper is not curled when you print on the back side of the paper with the Print Odd Pages and Print Even Pages settings.

- If smudged stains appear on the reverse side or at the bottom of the page:
NOTE: Illustrations shown below are from the representative product and may differ from your Brother machine.

• Make sure the printer platen is not dirty with ink.
  
  How to clean the machine's printer platen
  
  
  1. Unplug the machine from the AC power outlet.
  2. Lift the scanner cover until it locks securely in the open position.
  3. Clean the machine's printer platen(1) and the area around it, wiping off any scattered ink with a soft, dry, lint-free cloth.
     
     
  4. Close the scanner cover.
     
     
• Make sure you are using Genuine Brother Innobella™ Ink.
  > Brother Genuine Supplies information
  
  
  
• Make sure you are using the paper support flap.
  
  To use the paper support flap, pull out the paper support (1) until it clicks and unfold the paper support flap(2).
  
  

W8101/8102 - Print media position warning

Print media position warning
The paper over the platen lies too near or too far from the carriage home position
when fed into the printer.

Cause>
The paper on the platen was too close to or too far from the carriage home position
side when paper was fed.
<Probable faulty component>
The way in which paper is set, print paper, cassette/cut-sheet feed unit, carriage
unit, encoder sensor unit, linear scale, carriage controller, head controller, system
controller.
<Action>
1. Paper setting check:
Reset the paper if the setting is not correct.
2. Paper check:
Replace the paper when any stains or pre-prints are found.
Straighten or replace the roll media when the roll of paper is ruffled.
3. Cassette unit/cut-sheet feed unit:
Replace the faulty paper feed component when the paper feeding is performed
correctly in all parts except where the error occurred.
4. Check the linear scale:
Visually check the linear scale for abnormal conditions, such as stains or damage.
5. Replace the carriage unit.
6. Replace the head controller.
7. Replace the system controller.

Sensor strip stained for sure...sometimes they get a haze from ink and dont come off, these strips need to be 100% spotless, there is nothing else that gauges position besides the strip and the photocell that reads such, never have I seen it be any other than paper in the path or stained/dirty strip...

If smudged stains appear at the top center of the printed page:

• Make sure the paper is not too thick or curled.
  Also, verify that the appropriate paper is being used and that the paper type set in the machine matches the media used.
• Make sure the paper is not curled when you print on the back side of the paper with the Print Odd Pages and Print Even Pagessettings.

- If smudged stains appear at the right or left corner of the printed page:

• Make sure the paper is not curled when you print on the back side of the paper with the Print Odd Pages and Print Even Pagessettings.

- If smudged stains appear on the reverse side or at the bottom of the page:
NOTE: Illustrations shown below are from the representative product and may differ from your Brother machine.

• Make sure the printer platen is not dirty with ink.
  
  How to clean the machine's printer platen
  1. Unplug the machine from the AC power outlet.
  2. Lift the scanner cover until it locks securely in the open position.
  3. Clean the machine's printer platen(1) and the area around it, wiping off any scattered ink with a soft, dry, lint-free cloth.
  4. Close the scanner cover.
• Make sure you are using Genuine Brother Innobella™ Ink.
  > Brother Genuine Supplies information
  
• Make sure you are using the paper support flap.
  
  To use the paper support flap, pull out the paper support (1) until it clicks and unfold the paper support flap(2).

Cleaning the Interior of the Machine If the interior of the machine becomes dirty, paper printed onto by the machine may get dirty, so we recommend performing
cleaning regularly.
Note: Ensure that the Inner Cover is closed.
1. Press <ON/OFF> to turn on the machine, then remove any paper from the Auto Sheet Feeder.
2.Press the Open button to open the Paper Output Tray, and open up andset the extension by pressing down the hollow on the front side.
3.Prepare a single sheet of A4- or Letter-sized plain paper. Fold it inhalf along the long edge. Unfold the paper, then load it in the AutoSheet Feeder with the open side to the front.
4. Start bottom plate cleaning.

1. Press <COPY>.
   
2. Press <Menu> repeatedly to select [4.MAINTENANCE].
   
3. Use [ ] or [ ] to select [BOTTOM CLEANING], then press <OK>. The sheet of paper is automatically fed in and then out of the machine.

Ifthe printed paper is smudged, clean the inside of the machine again. Ifthe problem remains after performing cleaning again, the protrusionsinside the machine may be stained. Clean them up.
Note:Even if the Cassette is selected as the paper source, paper will be fedfrom the Auto Sheet Feeder. Do not perform any other operation whilethe bottom plate is being cleaned.
Cleaning the Protrusions inside the Machine

If protrusions inside the machine are stained, wipe ink off the protrusions using a swab or the like.


I hope it helps!!!