Working the Board .......................................................................................
A keyboard experiences two possible types of failure: mechanical and
electronic. Let me begin with the mechanical side. A keyboard is a box of
switches; when you press or release a key you are making or breaking con-
tact with a tiny grid of wires beneath. The contact or release is recognized
by a specialized processor that determines the switch location and converts
the signal into a standard scan code for the key. That code is passed along
to the computer’s CPU.On the mechanical side, one of the most common sources of a problem
involves dirt or other foreign substances interfering with the key’s action.
It is also possible that a spring, dome, or foam piece can become damaged.
The other common cause of mechanical failure is unintentional administra-
tion of aqueous, caffeinated, or phosphoric substances. In other words:
spilling water, coffee, or soda on the keyboard.Keyboard Maintenance Department..........................................................
Look at some basic rules for proper keyboard hygiene:Keep your laptop away from food and drink.This is especially
important — and difficult — when you are using the machine on the
seatback table of an airliner.Think about your work habits: Do you sit at the keyboard like Homer
Simpson, with a sugar donut in one hand and a brew in the other?
Cookies, chips, and sandwiches produce crumbs that can fall into the
crevices around keys.
Be especially alert when a flight attendant reaches over to hand a drink
to someone sitting beside you. (This is one reason you might want to
request a window seat if you are planning to use a laptop on a flight.) And
watch out for the spray of sticky soda when a can is opened near you.164 Part III: Laying Hands on the Major Parts
Spongeworthy
The earliest designs for keyboards used individ-
ual switches beneath each key. More modern
(less expensive and generally more reliable)designs use a two-layer, flexible, printed circuit
held apart by rubber domes, spongy foam, or tiny
springs.