Common Mechanical Failures on Laser Printers

By Elizabeth Mott

Mechanical failures with a laser printer often require expert attention.
i Creatas/Creatas/Getty Images

Problems with laser printers often stem from poor-quality paper or empty, failing or damaged toner cartridges. But like any complex piece of electronic hardware, a laser printer can ship with or develop mechanical problems. If your laser printer continues to malfunction or to produce poor-quality output even after you load suitable paper and replace consumables, your troubleshooting efforts may point to mechanical failures in the device itself.


Toner consists of a mixture of powdered plastic and coloring agents, as well as other substances that enhance its bond with paper. That bond owes its strength and permanence to the fuser mechanism, which melts toner onto the surface of each page. A fuser that fails to operate correctly can lead to printer output that fails to bond thoroughly. In these cases, the page image flakes or brushes away when you touch it. Fuser failures can relate to insufficient heat production or the buildup of excess toner on fuser parts.

Guides & Rollers

From the point at which paper enters the printer to its exit into the output tray, each sheet makes its way through the output process via guides and rollers that pull and push it. Rollers can harden as they age, reducing their ability to use friction to manipulate paper. Stray toner from leaky cartridges or the byproducts of the output process can build up on the surfaces of the rollers and cause them to leave marks on the paper. Dirty guides can leave marks on the edges of sheets. Crooked guides can cause misfeeds that lead to paper jams.


Laser printers' internal mechanisms rely on a multitude of gears to propel paper through the printing path and to activate other parts of the printing mechanism. Nicked gear teeth can lead to paper misfeeds and to misprints caused by paper that fails to reach the proper location in the printing process at the right time. Broken gears can cause the printer to fail to load paper because the paper-moving machinery can't operate.


Whether they fold down or flip out to provide temporary support for manually fed paper, pull out and push in to load larger paper quantities or function like drawers for ream-at-a-time loading, properly functioning paper trays feed output supplies one sheet at a time. Worn parts can produce situations in which multiple sheets try to enter the printer simultaneously, resulting either in a paper jam or a misfeed in which parts of the printed image of a single page end up printed on more than one sheet.