The following suggestions are not intended to be prescriptive or comprehensive. Always refer to the documentation accompanying your printer before attempting any preventive maintenance on the machine.

• Vacuum around inside occasionally to prevent a build-up of loose paper particles.
  
• Make sure that any belts used are at the proper tension.
  
• Clean the paper and ribbon paths periodically. Use a dry lint-free cloth. Plastic gloves will protect your hands from ink residue build-up.
  
• Clean the corona wires and rollers on a laser.
  
• Do not lubricate any moving parts, except as directed by your owner's manual.
  
• Try to maintain a narrow range of temperature and humidity around printers. Some printer components may be sensitive to environmental changes.
  

Preventing Problems with Laser Printers

• Toner cartridges can open in transit and create a mess. Always ship them in their protective sealed packaging and separately from the printer.
• Be sure to take the time to clean the corona wire and the roller every time you change the print cartridge.
• Laser printers need to dissipate a lot of heat. Give them adequate ventilation.
• Refilled toner cartridges work fine and save money, as long as they have only been refilled once. After that, they can become unreliable. Patronize only reputable vendors that you know refill them only once.
• Be careful when using envelopes and address labels in laser printers that are not intended for laser use. If the glue melts during fusion, there could be expensive damage.

Preventing Problems with Dot Matrix Printers

• Make sure the print head has enough free air around it to dissipate heat. Do not place other electronics too close to it.
• Use good quality ribbons. The cheap ones may use ink that lacks needed lubricants or uses an acid that can hurt your print head over time.
• Do not turn the platen head using the knob when the printer is on. This can damage the stepper motor. A system administrator may wish to use the knob when first loading a new box of paper and then remove it from the machine.
• Dot matrix printer ribbons will dry out eventually if they are not used.
• Some dot matrix printers do not have the strength of impact to deal effectively with multi-part forms.
• Check with the Seiko Epson Corporation before trying to replace the print head on its older dot matrix models. Some of these routinely burned out the main circuit board when the print head failed.
• It is often cheaper to get a standard stepper motor from a local electronics store than to order it by part number from the printer's manufacturer.
• A dot matrix printer has more control of its dot placement up-and-down than right-to-left. Its right-to-left motion is precise to 1/216th of an inch. Vertical spacing is accurate to 1/240th. This will effect the appearance of detailed graphics.

*These are the recommended maintenance for computer printers taken from HP website.