Chapter
6
–
Troubleshooting
●
If
you
don’t
get
an
OK
,
the
problem
may
still
be
in
the
communication
software.
Make
sure
you
have
done
whatever
is
necessary
in
your
software
to
make
a
port
connection.
Not
all
communication
programs
connect
to
the
COM
port
automatically.
Some
connect
when
the
software
loads
and
remain
connected
until
the
program
terminates.
Others
can
disconnect
without
exiting
the
program.
The
modem’s
TR
indicator
lights
to
show
that
the
software
has
taken
control
of
the
modem
through
the
COM
port.
●
Your
communication
software
settings
may
not
match
the
physical
port
to
which
the
modem
is
connected.
The
serial
cable
might
be
plugged
into
the
wrong
connector—check
your
computer
documentation
to
make
sure.
Or
you
might
have
selected
a
COM
port
in
your
software
other
than
the
one
the
modem
is
physically
connected
to—compare
the
settings
in
your
software
to
the
physical
connection.
●
If
the
modem
is
on,
the
cable
is
plugged
into
the
correct
port,
the
communication
software
is
configured
correctly,
and
you
still
don’t
get
an
OK
,
the
fault
might
be
in
the
serial
cable.
Make
sure
it
is
firmly
connected
at
both
ends.
●
Is
this
the
first
time
you
have
used
the
cable?
If
so,
it
may
not
be
wired
correctly.
Check
the
cable
description
on
the
packaging
to
make
sure
the
cable
is
the
right
one
for
your
computer.
●
Peripheral
expansion
cards,
such
as
sound
and
game
cards,
might
include
a
serial
port
preconfigured
as
COM1
or
COM2.
The
extra
serial
port,
or
the
card
itself,
may
use
the
same
COM
port,
memory
address,
or
interrupt
request
(IRQ)
as
your
communication
port.
Be
sure
to
disable
any
unused
ports.
●
The
serial
port
might
be
defective.
If
you
have
another
serial
port,
install
the
modem
on
it,
change
the
COM
port
setting
in
your
software,
and
try
again.
●
The
modem
might
have
a
problem
beyond
the
scope
of
this
user
guide.
If
you
have
another
Multi
‐
Tech
modem,
try
swapping
modems.
If
the
problem
goes
away,
the
first
modem
is
possibly
defective.
The
Modem
Cannot
Connect
When
Dialing
There
can
be
several
reasons
the
modem
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
●
poor
line
conditions.
You
can
narrow
the
list
of
possibilities
by
using
extended
result
codes.
Extended
result
codes
are
enabled
by
default.
If
they
have
been
disabled,
include
V1X4
in
the
modem’s
initialization
string,
or
in
terminal
mode
enter
ATV1X4
and
press
E
NTER
.
When
you
dial
again,
the
modem
reports
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
corporate
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.
Multi
‐
Tech
Systems,
Inc.
MT9234ZBA
‐
Series
User
Guide
25
