Lanier 6720 When printing the pages come out streaked in line with direction of paper travel

Most likely a page was scanned with 'white out' (Liquid Paper), still wet on the page. As the page feeds over the scanner, (a narrow strip of glass that runs across the width of the page along the feed path) the wet liquid paper comes off on the glass as a thin line and dries. Thereafter, when copying, the scanner light does not go through the liquid paper streak and the result when printed is a thin vertical line that runs the full length of the page.

If this is your problem: follow the path that the paper travels when sending a fax or making a copy, until you find the scanner (narrow glass strip). Take a clean, soft cloth and a small amount of methylated spirit (or white spirit) and remove the now dried Liquid Paper from the glass. Clean the whole strip ensuring that the glass is left clean and dry.

Problem could be on the Glass or Mirrors.
Also could be the blk drum unit

Print out a counter page.
If the line is present clean the charge roller in the drum unit

If it is not present clean the glass and mirrors

Good Luck

Most likely a fax has been sent or a page copied with 'white out' (Liquid Paper), still wet on the page. As the page feeds over the scanner, (a narrow strip of glass that runs across the width of the page along the feed path) the wet liquid paper comes off on the glass as a thin line and dries. Thereafter, when copying, scanning or sending a fax, the scanner light does not go through the liquid paper streak and the result when printed is a thin vertical line that runs the full length of the page. If this is the cause you will also find that faxes you send to other people will also have this line (although faxes you receive are not affected by this problem with your machine).

To fix the problem: follow the path that the paper travels when sending a fax or making a copy, until you find the scanner (narrow glass strip). Take a clean, soft cloth and a small amount of methylated spirit (or white spirit) and remove the now dried Liquid Paper from the glass. Clean the whole strip ensuring that the glass is left clean and dry.

Most likely a fax has been sent or a page copied with 'white out' (Liquid Paper), still wet on the page. As the page feeds over the scanner, (a narrow strip of glass that runs across the width of the page along the feed path) the wet liquid paper comes off on the glass as a thin line and dries. Thereafter, when copying, scanning or sending a fax, the scanner light does not go through the liquid paper streak and the result when printed is a thin vertical line that runs the full length of the page.

If this is your problem: follow the path that the paper travels when sending a fax or making a copy, until you find the scanner (narrow glass strip). Take a clean, soft cloth and a small amount of methylated spirit (or white spirit) and remove the now dried Liquid Paper from the glass. Clean the whole strip ensuring that the glass is left clean and dry.

Make sure that all the paper trays have the correct size and direction (portrait or landscape) in both the copier and print driver.

Sounds like some of the magenta toner is left behind on the drum. The only way to fix it is to get a new cartridge.

Hi xander4265:
I
Streaks in direction of paper travel
There are dark lines running along
the page in the direction of paper
travel from the leading edge to the
trailing edge (B-size print shown).
The printer displays no error code.
Note A-size prints are processed
through the printer with the short
edge of the print parallel to the
direction of the paper path --
making horizontal print artifacts
parallel to the shot edge of the
print.
B-size prints are processed
through the printer with the long
edge of the print parallel to the
paper path -- making horizontal
artifacts parallel to the long axis
of the print.
1. Check the end of life for each of
the consumables by printing the
supplies usage page. From the front panel’s Printable Pages Menu, select
Print Supplies Page.
2. Run the solid fill test pages; From the front panel’s Printable Pages Menu,
select Service Pages, then select Print Solid Fill Pages. If the missing bands
only occur in a single primary color, replace the print cartridge of the affected
color.
3. Swap print cartridges and run another test print.
Note Under some circumstances, streaking may occur in the margin of
SRA3-size paper. This is due to the edges of the paper extending
beyond the end of the imaging components. print-quality in the
margins of SRA3 paper is not guaranteed.
4. Inspect the Accumulator Belt cleaner; replace the cleaner, if necessary.
5. Run the Remove Print Smears routine. From the front panel’s Support Menu,
select Improve Print-Quality?, then select Remove Print Smears.
6. Replace the Developer Housing Assembly (RRP 27, on page 7-171).
7. Remove the print cartridge and (with a flashlight) check for debris along the
edge of the developer housing.
3041-42
Leading Edge
hope that this will help you.

If streaking is occurring only at the bottom of the page (i.e. the last area to print as the paper is fed beneath the print head), the problem may be due to improper curl of the paper. Many inkjet printers (Canon especially), rely on a slight curl of the paper so that it is "bowed" when it travels beneath the print head.

To see if this is the problem, gently roll a sheet of paper so that the print side is on the outside of the roll. When you place the paper in the feed area, it should have a very slight bow so that the center of the print side is slightly raised off the surface, while the edges are on the surface.

Also, make sure you use only OEM (Canon) cartridges. There is not a single "compatible" cartridge in the world that won't screw up your Canon print head. Take my word for it (and I DON'T work for Canon), you must use only Canon cartridges.

Check your photo conductor (drum) unit. This is often caused by an old or light damaged unit.