Printer Faults - Mono Page Misregistered

Pages sometimes don't print in the expected position and are too high, too low or alternate either way on the page.

Computer Settings

The most likely cause is that the correct paper type is not set up in the default computer settings - ie "US letter" instead of "A4". Find where the default settings and set the paper you normally use.

Computer software tends to default to US settings simply because that has been the biggest market and installation software is mass produced. It can be difficult to find where the default settings are actually lurking. Experience suggests many computers in small offices have the wrong page size set.

Computer driver settings will override the printer settings. The only reason the printer's own setting may be needed is that if a pure text file is sent - from one of the Unixes for instance - then the printer uses its built-in settings to skip the page margins.

Printer Faults

If the settings for pagelength are correct and printing misses the page then the feed mechanism is suspect - possibly the feed or registration rollers. The pickup rollers should be largely disengaged by the time paper has made it to the registration station. Registration rollers themselves are usually a hard material and don't wear much. A significant issue with some printers is the timing of the registration rollers which are probably controlled by a clutch or solenoid. If the clutch slips the page will be late arriving at the print station and the print will be too far down the page. A sign of this being the problem is that the print position is not systematically out; its erratic and sometimes the printer claims there is a paper jam. Another hint is that there is some vertical distortion - character heights vary.

Changing the registration clutch is a moderately frequent repair for persistent misregistration. On almost all printers it will mean removing covers and possibly dismantling part of a cog drive chain.

For some printer models the paper feed station can be bought as a complete unit. This may sometimes be an easier solution to the problem.

Depending on the printer design it is unlikely that printing can be positioned to a tolerance of better than one or two millimetres. Cut sheet feeding inevitably involves some freedom for the sheets to move. Fitting print very precisely into small boxes on a form or pre-printed form letter may not be possible. There may be mention of the vertical print registration in the detailed specification for the printer.