by a radiator; made fragile by direct exposure to sunlight; or pinched and
shorted out by the weight of desks, chairs, computers, and other devices.If you have any doubt about the quality or serviceability of an external cable,
try substituting a known-good replacement.Is the device properly connected to a working telephone jack?
Test a conventional dial-up modem by plugging in a known-good standard
telephone to the socket and see if you receive a dial tone. While you’re at it,
try dialing the number to reach your ISP; you should hear the beeps and
squeals of the modem at the other end of the line trying to communicate with
your laptop. If the phone line is dead, then you know you’ve got something to
discuss with the telephone company and not a problem with either your
modem or your laptop.If your incoming phone line seems to be dead, you can find out if the problem
is within your home or office by locating the phone company’s network inter-
face. This is usually a small gray or black box at the point where the phone
cable comes in from the pole or an underground vault. Your phone company
should be able to assist you in locating it and instructing you on how to open
the box and plug a working telephone into the home or office side of the con-
nection; if no signal is there, then you know the problem belongs to the
phone company.On the other hand, if your phone works at the network interface, that tells you
something is wrong with the internal wiring of your home or office. That prob-
lem belongs to you to fix or to hire someone to troubleshoot. If the problem is
on your side, you may be able to save yourself the not-inconsiderable cost of a
visit by an electrician or a telephone technician by disconnecting every phone
device in your home or office. (Devices include phones, fax machines, answer-
ing machines, and possibly burglar, fire, and other types of alarms.)Connect a simple phone to the jack nearest the interface; if you have a dial
tone, bring that same phone to each and every jack to try them. If you find a
dead jack, you may have located a problem with that jack or the wiring that
leads to it; a short in either could, in certain circumstances, add a hum to the
line or bring down the entire system.If all of the jacks are live, you can then reconnect each of the various devices.
Check each one for a dial tone and other functions before moving on to the
next. You may find that reconnecting one device may add a hum or shut down
the system because of a short in its cable, an internal short, or a failure of an
electronic circuit within.Certain wireless phone systems are susceptible to interference. You might be
amazed to find out all of the various sources of radio frequency (RF)energy
in a home or office. They include things like microwave ovens, garage door234 Part IV: Failing to Communicate