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Chapter 6 - Troubleshooting
The Modem Dials But Cannot Connect
There can be several reasons the ZBA fails to make a connection. Possibilities include
• lack of a physical connection to the telephone line.
• a wrong dial tone.
• a busy signal.
• a wrong number.
• no modem at the other end.
• a faulty modem, computer, or software at the other end.
• incompatibility between modems.
You can narrow the list of possibilities by using extended result codes. Extended result
codes are enabled by default. If they have been disabled, enter ATV1X4 and press
ENTER while in terminal mode, or include V1X4 in the modem’s initialization string.
When you dial again, the modem will report the call’s progress.
•
If the modem reports
NO DIALTONE
, check that the modem’s telephone line cable is
connected to both the modem’s LINE jack (not the PHONE jack) and the telephone
wall jack. If the cable looks secure, try replacing it. If that doesn’t work, the problem
might be in your building’s telephone installation. To test the building installation, plug
a telephone into your modem’s telephone wall jack and listen for a dial tone. If you
hear a dial tone, your modem might be installed behind a company phone system
(PBX) with an internal dial tone that sounds different from the normal dial tone. In
that case, the modem might not recognize the dial tone and might treat it as an error.
Check your PBX manual to see if you can change the internal dial tone; if you can’t,
change your modem’s initialization string to replace X4 with X3, which will cause the
modem to ignore dial tones (note, however, that X3 is not allowed in some countries,
such as France and Spain).
•
If the modem reports BUSY, the other number might be busy, in which case you
should try again later, or it might indicate that you have failed to add a 9, prefix to the
phone number if you must dial
9
for an outside line.
If you must dial
9
to get an outside line, the easiest way to dial it automatically is to
include it in the modem’s dial prefix, e.g., ATDT9,. Note the comma, which inserts a
pause before the number is dialed. By inserting 9, into the dial prefix, you do not
have to include it in each directory entry.
To change the dial prefix in Windows 98 HyperTerminal, select Call from the Call
menu, click Dialing Properties, and type 9 in the local and long distance boxes in
How I dial from this location.
•
If the modem reports
NO ANSWER
, the other system has failed to go off-hook, or
you might have dialed a wrong number. Check the number.
•
If the modem reports
NO CARRIER
, the phone was answered at the other end, but
no connection was made. You might have dialed a wrong number, and a person
answered instead of a computer, or you might have dialed the correct number but the
other computer or software was turned off or faulty. Check the number and try again,
or try calling another system to make sure your modem is working. Also, try calling
the number on your telephone. If you hear harsh sounds, then another modem is
answering the call, and the modems might be having problems negotiating because
of modem incompatibilities or line noise. Try connecting at a lower speed.