Printer Faults - Vertical White Stripes

Vertical stripes are usually coming from one of the rollers making up the printer. White stripes - missing bits in print down the page - tend to point to particular rollers - mainly the developer and transfer roller.

Developer Roller.

The developer roller carries toner to the photoconductive drum. If the developer has a fault insufficient toner will arrive leaving a white stripe in areas that should be black. Developer rollers have a bit of a tendency to get this fault. Many developers have a strong magnet inside them and if a fragment of metal gets into the machine it will be attracted to the developer and then get stuck between it and the doctor blade. The developer roller is commonly aluminium or conductive plastic and the particle wears a groove.

Transfer Roller.

Damage to the transfer roller from a paper-clip or suchlike is a possibility. If the transfer roller is damaged it will tend not to pull toner across from the drum in that area.

OPC Damage.

Damage to the OPC such as scoring of its surface is most likely to create black lines down the page. Contamination of its surface might create white marks.

Can't Write to the OPC.

On print-black lasers something may be obstructing the laser path.

On an LED printer part of the page not printing suggests a misseated print-head connector or a segment of the drive electronics has failed.

If physical examination doesn't make it evident whether the optical path, developer roller or transfer roller is to blame try a stop test. Examine the print cartridge drum by looking inside the cartridge shutter. Try deliberately obstructing the laser path to see if that changes the fault.