### Original link: http://mediamatrix.org/pp.htm#d681d
Courtesy David Roscoe

# Printer Problems

Though we live in the computer age, we continue to use paper, a lot. We often need to get paper copies of something in our computer. So when something goes wrong with the printer, that is a serious Computer Problem.

Most of my printer problems were annoying, but temporary, and showed no physical evidence of any cause. But one of my printer problems was very different.

In late summer of 2004 my printer began jamming badly. Every page jammed near the rear of the printer. This problem did not go away, and the printer was useless.

I investigated and discovered that the paper was jamming because rollers at the back of the printer had been damaged.

The above image is a side rear view of two printers. Their rear output trays have been folded down to expose the 5 rollers each that transport printed pages out of the printing mechanism.

- The printer on top is my printer that jammed. It is an HP LaserJet 6MP,

- The printer underneith is a mechanically identical HP LaserJet 6P that I got to canabalize for parts.

The above image is a close up of the rear of the parts printer. It shows 2 white plastic rollers and 3 black rubber rollers, all in good condition.

The above image is a close up of the rear of the printer that jammed. The 2 white rollers are fine. But the 3 black rollers are severly damaged. They were soft, sticky, and deformed. No page could go past them without sticking, jamming, and being marked with black stripes, one from each black roller.

The black rubber roller on the far left was the worst. It was more of a blob than a roller. It was so soft that the nearby white roller had pressed a groove into it.

I contacted several companies to ask about this roller problem. Nobody had seen it before. One of them said that the rubber rollers could have been damaged that way by somebody applying "rubber rejuvinator" to them. But I had never applied anything to them, and I was the only person with access to the printer.

I did some research on HP printers and learned that these rollers do not normally wear out or fail. They are not part of widely available "roller kits" recommended for refurbishing these printers after 100,000 printed pages. This makes the roller damage more remarkable, because:

- the jamming printer with the bad rollers had printed less than 14,000 pages;
- the parts printer with the good rollers had printed almost 51,000 pages.

I concluded that my roller damage was the result of sabotage.