Impact Printer

How does an impact (dot matrix) printer work?

A printed containing a column of metal pins (typically nine or 24) strikes an ink ribbon against the paper, transferring ink through mechanical impact

• The printhead moves horizontally across the page firing combinations of pins to form characters and graphics dot by dot

What is multipart (carbonless) paper?

Paper that consists of multiple layers - the impact from printing simultaneously creates an impression on all layers at once

Where are impact printers still used?

In situations where carbon copies are legally required (multiparty forms)

• For example, invoices, receipts, manifest, custom forms

What is an impact printer ribbon?

Inked fabric loops in a cartridge that loops through the printhead continuously

How do you replace an impact printer ribbon?

1. Power off the printer

2. Open the access cover

3. Slide the old ribbon cartridge out

4. Route the new ribbon cartridge through the old one’s path

5. Make sure the new ribbon sits correctly in front of the printhead pins

6. Close the cover and test print

How do you replace an impact printhead?

1. Power off and allow the printer to cool

2. Disconnect the printhead cable connector

3. Remove mounting screws and slide the print head off the carriage

4. Install the new printer and reconnect cable

5. Run a test print

What are the symptoms of a faulty printhead (pin assembly)?

Missing dots in characters, vertical white streaks, or specific characters always printing incorrectly

What paper can impact printers use?

They can use:

• Single sheet cut paper

• Continuous fanfold (tractor feed) paper with perforated edges and holes for the tractor pins

• Multi pot carbonless forms

What paper considerations applied to impact printers?

• The tractor feed mechanism must be adjusted to match the paper with

• Never use thermal paper in an impact printer - The heat from the printhead will blacken it

• Multi part forms, check the printers maximum copy thickness to avoid pin damage

Maintenance keep an impact printer running reliably?

• Replace the ribbon output fades

• Clean the paper path and platen with a lint free cloth to remove paper dust residue

• Inspect the platen for grooves

• Check tractor feed pins for where or damage

• Lubricate the carriage rail periodically

• Keep the printer covered when not in used to prevent dust