CompTIA A_ Certification All-In-One Exam Guide, Seventh Edition - Michael Meyers [387]
Network Printers
Connecting a printer to a network isn’t just for offices anymore. More and more homes and home offices are enjoying the benefits of network printing. It used to be that to share a printer on a network—that is, to make it available to all network users—you would physically connect the printer to a single computer and then share the printer on the network. The downside to this was that the computer to which the printer was connected had to be left on for others to use the printer.
Today, the typical network printer comes with its own onboard network adapter that uses a standard RJ-45 Ethernet cable to connect the printer directly to the network by way of a router. The printer can typically be assigned a static IP address, or it can acquire one dynamically from a DHCP server. (Don’t know what a router, IP address, or DHCP server is? Take a look at Chapter 23, “Local Area Networking.”) Once connected to the network, the printer acts independent of any single PC. Some of the more costly network printers come with a built-in Wi-Fi adapter to connect to the network wirelessly. Alternatively, some printers offer Bluetooth interfaces for networking.
Even if a printer does not come with built-in Ethernet, Wi-Fi, or Bluetooth, you can purchase a stand-alone network device known as a print server to connect your printer to the network. These print servers, which can be Ethernet or Wi-Fi, enable one or several printers to attach via parallel port or USB. So take that ancient ImageWriter dot-matrix printer and network it—I dare you!
Other Printers
Plenty of other connection types are available for printers. We’ve focused mainly on parallel, USB, FireWire, and networked connections. Be aware that you may run into an old serial port printer or a SCSI printer. Although this is unlikely, know that it’s a possibility.
Practical Application
The Laser Printing Process
The laser printing process can be broken down into six steps, and the CompTIA A+ exams expect you to know them all. As a tech, you should be familiar with these phases, as this can help you troubleshoot printing problems. For example, if an odd line is printed down the middle of every page, you know there’s a problem with the photosensitive drum or cleaning mechanism and the toner cartridge needs to be replaced.
You’ll look into the physical steps that occur each time a laser printer revs up and prints a page; then you’ll see what happens electronically to ensure that the data is processed properly into flawless, smooth text and graphics.
The Physical Side of the Process
Most laser printers perform the printing process in a series of six steps. Keep in mind that some brands of laser printers may depart somewhat from this process, although most work in exactly this order:
1. Clean
2. Charge
3. Write
4. Develop
5. Transfer
6. Fuse
* * *
EXAM TIP Be sure that you know the order of a laser printer’s printing process! Here’s a mnemonic to help: Clarence Carefully Wrote Down The Facts.
Clean the Drum
The printing process begins with the physical and electrical cleaning of the photosensitive drum (Figure 22-12). Before printing each new page, the drum must be returned to a clean, fresh condition. All residual toner left over from printing the previous page must be removed, usually by scraping the surface of the drum with a rubber cleaning blade. If residual particles remain on the drum, they will appear as random black spots and streaks on the next page. The physical cleaning mechanism either deposits the residual toner in a debris cavity or recycles it by returning it to the toner supply in the toner cartridge. The physical cleaning must be done carefully. Damage to the drum will cause a permanent mark to be printed on every page.
Figure 22-12 Cleaning