PC Hardware

Ink-Jet Printers

Ink-jet printers have replaced dot-matrix printers, in the low-end market, and thermal wax printers for the low-end color market. Many computer manufacturers and large computer stores offer an ink-jet printer as part of a computer-system package deal.

Ink-jet printers spray ink onto paper in order to form images. They produce good-quality printing and-compared to dot-matrix and wax printers-they are relatively fast. They also require little maintenance beyond cleaning and ink-cartridge replacement. What makes them so attractive is their ability to easily produce color as well as standard black-and-white images.

When installing a new ink-jet cartridge or replacing the cartridge on an existing ink-jet printer, follow the instructions carefully! The cartridge is not just a simple ink container. It must be properly pressurized, and there are sensors on the unit (small metal plates) that must line up with contacts on the cartridge transport. Read the product manual for details.

When recommending an ink-jet printer, the cost of printing as well as the cost of the printer itself should be considered. The cartridges are usually more expensive per page than those for a laser printer.

You might find it cost-effective to equip an office with more than one kind of printer. Many offices have a heavy-duty, high-speed, black-and-white laser printer for text printing, an aging dot-matrix printer for forms and labels, and a color ink-jet printer for graphics. It is also common to find several printers available on the local office network.

If a printer fails to operate, the first step in determining the source of the problem is to decide if the problem lies with the printer or with the computer. The best place to start is at the printer, with a visual inspection. Look for simple issues, like a tray out of paper or a paper jam. Most printers have either an LED (light-emitting diode) panel or lights that warn of common problems.

If visual inspection of the printer does not turn up an obvious fault, proceed to the printer's self-test program. In most cases, you can initiate this routine by holding down a specified combination of control keys on the printer (check the owner's manual for diagnostic procedures) while you turn it on. If a test page prints successfully, the problem is most likely associated with the computer, the cabling, or the network. The following table lists some typical problems encountered with ink-jet printers and their possible causes.

Symptom Possible Cause
Power is on but device does not print. Printer is not online. Printer is out of paper.
Printer won't go online after user has replaced ink cartridge. Cartridge is installed incorrectly. Printer cable is disconnected.
Printer is plugged in, but all indicator lights are off and the printer appears to be dead. Check the drive mechanisms and motors for signs of binding. They might need to be replaced. Fuse is blown. (Check the power supply's fuse and replace with one of the same type and rating, if necessary.)
Print head does not print. Ink reservoirs are empty. (Check the ink supply and replace the ink cartridge as necessary.)
Paper does not advance. Paper-handling hardware is jammed. (Check the control panel to confirm that the printer is online. If so, you will need to inspect the paper-handling motor and gear train. You can do this by setting the printer offline and pressing down the form-feed button.)

Laser Printers

The laser printer has become the dominant form of computer output device, with models ranging from personal, low-volume desktop printers to behemoths that fill half a room and serve hundreds of users, churning out reams of pages every day.

All laser printers follow one basic engine design, similar to the ones used in most office copiers. They are non-impact devices that precisely place a fine plastic powder (the toner) on paper. Although they cost more to purchase than most ink-jet printers, they are much cheaper to operate per page, and the "ink" is permanent. (Most ink-jet images are, at best, water-resistant.)