HP Laserjet 4100 “Jitter”

Question

One of the HP LaserJet 4100s in my office has a problem that is hard to describe. I'll link some scans of the pages it prints below so that you can see exactly what is going on. My best guess is that it is printing vertical lines in the wrong order.

Here is a list of things I've already done to solve the problem, none of which seems to have had any effect at all:

1. The printer asked for a maintenance kit, so I purchased and installed the requested kit per the provided instructions. The maintenance kit included a fuser, so note that the fuser has been replaced.

2. I messed around in the printer settings and changed things like pitch, font, etc. None of which worked. After all of that, I reset the settings back to factory defaults.

3. I've replaced the toner just for the heck of it, with no improvement in print quality.

4. I tried printing configuration pages from the printer itself with the data cable detached, and the problem persisted. This tells me that drivers are not the issue.

Here are links to scanned versions of my printer output. There is nothing wrong with the scanned images, they represent the printed pages well:

Cleaning page:

Configuration page:

Answer 1

It sounds/looks like a fuser problem, but if you changed it and it made NO difference then that's kind of weird. :)

A user or two on FixYourOwnPrinter.com have a few ideas on tracking it down:

Do a half test. Put a sheet of paper on the manual feeder and run a self test from the menu. When the sheet is about 2/3 of the way in, open the top cover to stop the printer. Remove the toner and look at the image below. If it is distorted look at the remaining image on the drum of the toner cartrdige to see if it is distorted. If the image is ok, the fuser is the most likely cause. If the image is distorted and the toner drum is the same, it is most likely the high voltage or laser/scanner optics.

Answer 2

It looks like an optical fault or a fault with the opto mechanics - ie: the scanner mechanism is not running correctly so the laser scan pattern is distorted. A lot of that stuff is not user serviceable but you could check that the portal through which the laser beam shines is clean/clear and that the gears and cogs that drive the rotating bits (fuser, OPC drum and anything user replaceable that rotates) are not fouled with a bit of paper or anything that will stop smooth rotation. After that, it's a strip-down by someone who knows the printer.

Answer 3

It looks like a drive system problem. Have you verified that you installed the correct fuser and that the drive link between the fuser and the paper feed system (gear driven I'm sure) is correct? It may be that the fuser and drive system aren't meshing, causing the drive system to "jump" which would affect anything driven by the same drive "train", such as the drum. fuser, and paper feed.