PC Hardware

Laser Printer Ghosting

The term ghosting is used to describe unwanted images that are produced on the printed page at regular intervals. This usually occurs when the drum is not fully discharging or is being saturated with excess toner. One remedy is to print one or two totally black pages; this will pull the toner off on the drum and onto the paper. If the problem persists, try using a new toner cartridge (if the toner is part of the cartridge assembly). If those steps fail, the printer will require servicing by a trained technician, who is able to adjust the internal settings that regulate toner levels during printing.

Printing on Transparencies

When printing on transparencies, use only materials approved for laser printers. Laser printers generate far more heat than other types of printers-using the wrong material can cause serious damage.

Printing on transparencies can be hazardous to the printer. Improper material might melt and damage the internal components of a laser printer.

Printer's Hardware Problems

Most laser printers offer the ability to print a page or more of diagnostic and configuration information. If you suspect a hardware problem, print these sheets. Check for status lights, menu warnings, or error messages. The manual should list steps to be taken in troubleshooting the common problems that are indicated by the printer's display. The variety of error codes that exist, the result of different options on printers, even from the same vendor, makes a detailed listing beyond the scope of this volume and beyond the skills required for the exam. Refer to the printer's manual for details concerning codes for a given printer.

Lesson Summary

The following points summarize the main elements of this lesson:

  • Dot-matrix, ink-jet, and laser printers are the most widely used printers today.

  • As a computer technician, you can expect to encounter printing problems.

  • The key components of a laser printer are the power supply, photosensitive drum, eraser lamp, primary corona, laser, transfer corona, logic circuits, paper transport, and fuser.

  • Laser printing involves several steps: preparing the drum, imaging the page in memory, placing toner, and heating that toner to fix it on the page.

Next Lesson 2: Modems

Once an expensive and complicated option, the modem is now an integral part of the modern PC, thanks to the popularity of the Internet, faxes, and e-mail.

After this lesson, you will be able to:
  • Define how modems transmit data.

  • Define the difference between serial and parallel data transfer.

  • Install a modem.

  • Troubleshoot basic modem and communication problems.

  • Set up and test a modem.

Estimated lesson time: 45 minutes