Printer Streaks? The Mark on the Page Names the Part

Every page you print has a line down it in exactly the same place. Or your black comes out banded and thin. Either way you have run the cleaning cycle already. Probably more than once. And the page still comes out wrong.

Burning paper and ink on the same bad page is a miserable way to spend an evening. I would like to save you the rest of it.

Most advice hands you one list for every printer and every kind of mark. But a white line and a black line have opposite causes.

So sort by what you can see on the paper. The mark names the part.

Before anything: which kind of printer is this?

The two types share nothing mechanically. So this decides everything below.

An inkjet sprays liquid ink through tiny nozzles. Its faults are clogged nozzles and dried ink. Cleaning cycles are the right tool.

A laser printer uses toner, a drum and a corona wire. Its faults are dirt, scratches and worn parts. Head cleaning does not apply, because there is no head.

Not sure? Look at what you buy for it. Cartridges of liquid ink mean inkjet. A big plastic cartridge of powder, often with a separate drum unit, means laser.

Inkjet: gaps, banding or a missing color

Look for missing detail rather than an added line. Bands of pale, patchy coverage. Or one color absent from a picture you know should have it.

Documented by HP: run the printhead cleaning cycle two to three times in a row, from HP Smart or the printer's own control panel, under Settings, then Printer Maintenance, then Clean Printhead.

⚠️ Two or three times in a row, then stop. Every cycle uses ink. Twenty of them on a nearly empty cartridge makes things worse, not better.

Documented by HP for the next step: clean the copper-colored contacts on the cartridge and the matching contacts inside the printer with a lint-free cloth lightly dampened with distilled water, then let everything dry for five minutes before putting it back.

Reported by an adviser on Microsoft's boards, and it is neat diagnosis worth borrowing. Blue printing with red streaks through it points at the magenta head, not the blue one.

The blue you see is mixed from two inks. Only one of them is misbehaving.

Ours, and marked as ours: print a nozzle check page rather than judging on a document. It puts each color down as a solid block and a set of fine lines. A gap shows up plainly instead of hiding in your document.

Laser: a white line running down the page

White means ink is missing along that line. Something is blocking the light or the toner from reaching the paper.

Documented by Brother on its white lines page, which names three causes: "dirty or clouded laser glass, dust or glue on the drum surface, or use of non-genuine Brother toner."

The laser glass is the part nobody thinks to clean. It is a thin strip of glass inside your machine, sitting above the drum unit.

⛔ Brother is emphatic about how to clean it. Its instruction is to "clean the laser glass with a DRY cloth" and it says in capitals: "DO NOT use isopropyl alcohol or any liquid to clean the glass."

That matters, and I nearly missed it myself. Alcohol is exactly what you are told to use on the drum a few paragraphs later. Same machine, two parts, opposite instructions.

Brother's stopping point is clear too: "If the vertical white lines continue, the toner cartridge must be replaced." So there is a point where you stop cleaning and start buying.

Laser: a black line running down the page

Black means something is adding toner along that line. That is the opposite of your last problem, and it points somewhere else entirely.

Documented by Brother: it is "usually caused by foreign material inside the machine (paper dust, glue from labels or envelopes, paper clips, staples, etc.) sticking to or damaging the surface of the drum."

Note what is on that list. Envelope glue and label adhesive. Run sheets of labels through a laser printer lately? That is a likely history for this fault.

To find it, take out the drum unit. Turn the gear at its edge by hand and watch the whole surface go past you.

Brother says to gently wipe the marked area "with a lint-free cloth or cotton swab lightly moistened with isopropyl (rubbing) alcohol", then let it evaporate completely before reassembling.

⚠️ Found a scratch or a nick rather than a deposit? Stop cleaning. Brother says physical damage in the drum surface means the drum needs replacing. Rubbing at a scratch only makes it worse.

The stripe you can give yourself while fixing this

⭐ Here the cleaning step itself can hand you the exact fault you are trying to remove.

Both of Brother's procedures have you clean the corona wire. You slide a small tab along the top of the cartridge, back and forth. That part is straightforward.

Then Brother says this, and almost nobody repeats it: "Be sure to return the green tab to the Home position. The arrow on the tab must be aligned with the arrow on the drum unit. If not, your printed pages may have a vertical stripe."

So a tab left even slightly off center gives you a vertical stripe down every page.

⭐ Read that again if you have cleaned this printer before. If your streak started after a cleaning rather than before it, go and look at that tab first. It is a ten second check and it is free.

When cleaning has stopped being the answer

Both manufacturers name a point at which you stop trying. Knowing it saves an evening, in the same way that knowing when to stop on a computer that will not turn on does.

Brother's rule for a black line: replace the drum if black lines are still there after at least two full manual cleaning cycles, or if the drum surface has any physical damage.

Brother's rule for a white line: if the white lines continue after cleaning, the toner cartridge must be replaced.

Ours, and marked as ours: the cheapest real test is a spare part, not another cleaning cycle. Borrow a drum or a cartridge from an identical machine for one page. You will know in a minute what an hour of cleaning cannot tell you.

What is worth doing on the computer, and what is not

Very little of this is a Windows problem, and it is worth being blunt about that. If your printer will not print at all, a printer that says it is offline is a different page entirely.

Two things are worth doing and both are free. Set print quality to Best in the print dialog, and match the Paper Type to what is actually in the tray. Firmware updates occasionally fix genuine banding faults too.

⚠️ Reinstalling the driver will not remove a physical streak. It gets suggested constantly.

Print the printer's own internal test page, with no computer involved. Same mark? Then the computer cannot be the cause.

That internal test page is the most useful thing here. It takes the driver, the cable and Windows out of the picture. One step.

Status: written 21 August 2026. Brother documents a corona wire tab left off its home position as a cause of a vertical stripe, so the standard cleaning can create the fault it is meant to cure.

Why does my printer print lines down the page?

The color of the line tells you which part. On a laser printer a white line points at dirty laser glass, dust on the drum or non-genuine toner. A black line points at foreign material stuck to the drum, often glue from labels or envelopes. On an inkjet it is usually blocked nozzles.

Why does my printer still streak after cleaning the printhead?

Because cleaning cycles only address blocked nozzles, and not every streak is a blocked nozzle. Check the cartridge contacts with a lint-free cloth and distilled water, print a nozzle check to see exactly which color is failing, and stop after two or three cleaning cycles rather than repeating them.

Can cleaning a laser printer cause a stripe?

Yes. Brother's own instruction warns that if the corona wire tab is not returned to its home position, with the arrows aligned, printed pages may have a vertical stripe. If your streak appeared after you cleaned the printer, check that tab before anything else.

When should I replace the drum instead of cleaning it?

Brother gives two triggers: any physical damage such as scratches or nicks in the drum surface, and black lines that survive at least two full manual cleaning cycles. For white lines that persist after cleaning, it is the toner cartridge rather than the drum.

The Short Version

• Inkjet and laser share no mechanism, so decide which you have before following any advice.
• A white line on a laser points at laser glass, drum dust or non-genuine toner.
• A black line points at foreign material on the drum, often glue from labels or envelopes.
• Brother says clean the laser glass DRY, and never with alcohol, though the drum does want alcohol.
• A corona wire tab left off its home position causes a vertical stripe on every page.
• The printer's own internal test page proves whether the computer is involved at all.

Where to Next

Print the printer's internal test page before anything else on this list. If the mark is there, no driver, cable or Windows setting can be the cause. That saves you the entire software half of the internet's advice.

Printing nothing at all rather than printing badly? Try a printer that says it is offline instead, which is a queue problem rather than a parts one.

And if the mark on your page does not match any of the four here, describe it in the comments and I will tell you what I would check. The shape of the mark really does name the part.