AT&T MERLIN Plus System Manual page 185

7-6 Section 7: Troubleshooting the System
SYMPTOM: Trouble with voice terminal lights, speaker, and ringing
(continued).
Possible Cause 3: Cable connections.
Do This
Step 1.
Go to the control unit and
locate the intercom jack for
the malfunctioning voice
terminal and an intercom
jack for a working voice
terminal. Unplug both from
the control unit and replug
each into the other's jack
See if the trouble occurs on
the working voice terminal.
Step 2.
Test each cable in the
wiring run to the previously
malfunctioning voice
terminal by following this
procedure:
a. Connect the wiring run
to a functioning voice
terminal.
b. Replace the first cable in
the wiring run with one
known to be working.
If
The trouble still occurs on
the previously working voice
terminal
The trouble no longer
occurs on the working voice
terminal
The trouble still occurs
The trouble no longer
occurs
Then
The problem is caused by
your control unit. Call your
equipment supplier for
assistance.
The trouble is caused by a
cable (there may be more
than one) in the wiring run
to the malfunctioning voice
terminal. However, check
the previous two causes
for this symptom first. If the
problem persists go on to
Step 2 of this cause.
Check the connection; if
the connections are correct
and secure, remove the
second cable in the wiring
run and replace it with
another Cable that is known
to work properly. If the
problem still occurs, replace
the third cable in the run
and so on until all the cable
in the run has been
replaced. If the problem
still persists, call your local
equipment supplier for
assistance.
The cable was the source of
the problem; discard the
malfunctioning cable.