Printer Faults - Vertical Stripes

Vertical stripes are usually coming from one of the rollers making up the printer. If the stripe is continuous and thin that suggests the photoconductive side of things - ie the cartridge. If the stripe is wide and blotchy that might suggest the fuser.

If the printer has a cleaning mode, try that. If not try manual inspection and cleaning. If the mark persists.

Typical causes are:

  • Dirty corona wire if the printer has them. In a Brother printer there is a blue corona wire wiper slide on the drum - slide it back and forth a couple of times to clean the wire. Put it back in the rest position or it will cause a stripe.
  • Photoconductive drum is damaged by scoring. Turn the print cartridge over, open its shutter and look for damage that would match the line seen on the page.
  • Examine the transfer roller - is it damaged (this would more likely lead to a white stripe because the transfer voltage would be missing.)
  • Likewise scoring of the developer roller tends to create white stripes where it fails to present any toner to the OPC.
  • Cleaner blade damage will create a grey stripe. It leaves a bit of the OPC drum with a continual background of toner on it, this will create a vertical grey stripe - there may be a discernible repeat pattern in it.

Thin, straight black lines down the page tend to be bad news. Take the cartridge out, open the flap that covers the OPC drum and look at its surface - is there a continual score line corresponding with what is seen on the page? The score line will tend to be the silver of the aluminium itself. With a write-black laser process the metal surface of the drum always attracts toner. If the surface of the OPC drum is scored it is a write-off, so the cartridge is ruined.

How this happens is a matter of speculation. Grit or metal fragments getting into the paper feed seems possible, once it gets to the cleaner blade it is too big and gets rammed into the drum surface grinding it away.

Metal fragments like paper clips could do the same kind of damage. They might be very attracted to magnets and there is a powerful magnet in the developer.

It is rarely clear what got into a printer to wreck the mechanism; whatever caused the damage usually gets ground up by the roller it is destroying. Human hair quite commonly blocks the waste toner augurs on printers but it doesn't seem to do much other damage.

The position a printer is in might be an issue. Could things like dust and grit fall onto the printer or its paper trays. If so they would be attracted by the electrostatic fields in the machine. Has the cartridge been put down on a surface where it could pick up a staple?

If there is a score line on the OPC drum but it is black then it's worth trying to clean it away with a damp tissue (or if that doesn't work, isopropyl or meths). Greasy materials or adhesive from labels can leave a deposit that the cleaning blade just smears onto the surface.

Scoring in developer and cleaner blades isn't easily curable in most modern printers, they are inside the print cartridge and can't be seen.

Wider stripes

Wide and blotchy vertical marks tend to come from the fuser - either contamination with sticky material such as from envelopes or labels or the hot roller coating or foil is degenerating. If you find contamination of the fuser roller or foil don't try to remove it by scraping, use a damp tissue with water, methylated spirit or isopropyl alcohol.

Wide grey stripes on older printers generally suggest that one of the erase LEDs in the waste toner cleaner has failed.