CompTIA A+ Certification All-in-One Exam Guide

Flashing is a lot like upgrading the system BIOS, which you learned about in
Chapter 5, “Firmware.” Upgrading the firmware can help fix bugs, add new
features, or update the fonts in the printer.
Of particular importance is the printer’s RAM. When the printer doesn’t
have enough RAM to store the image before it prints, you get a memory
overflow problem. Also, some printers store other information in the RAM,
including fonts or special commands. Adding RAM is usually a simple job—
just snapping in a SIMM or DIMM stick or two—but getting the right RAM
is important. Call or check the printer manufacturer’s Web site to see what
type of RAM you need. Although most printer companies will happily sell
you their expensive RAM, most printers can use generic DRAM like the kind
you use in a computer.
Ozone Filter The coronas inside laser printers generate ozone (O 3 ).
Although not harmful to humans in small amounts, even tiny concentrations
of ozone will cause damage to printer components. To counter this problem,
most laser printers have a special ozone filter that needs to be vacuumed or
replaced periodically.
Sensors and Switches Every laser printer has a large number of sensors and
switches spread throughout the machine. The sensors are used to detect a
broad range of conditions such as paper jams, empty paper trays, or low toner
levels. Many of these sensors are really tiny switches that detect open doors
and so on. Most of the time these sensors/switches work reliably, yet
occasionally they become dirty or broken, sending a false signal to the
printer. Simple inspection is usually sufficient to determine if a problem is
real or just the result of a faulty sensor/switch.
3-D Printers
3-D printers (Figure 26-12) use melted material to create prints of threedimensional
objects. The most common 3-D printers use plastic filament on
spools (see Figure 26-13). Some 3-D printers enable you to print with
multiple colors.