Trouble With Indicator Lights, Speaker, Or Ringing - AT&T Merlin 820 Service And Maintenance Manual

C. Trouble with Indicator Lights, Speaker, or Ringing
Hold the T/P switch on the left side of the voice terminal in the T (test)
Step 1.
position.
IF
All red and green lights flash
alternately and a tone sounds con-
tinuously,
The red and green lights appear
dim,
There is any other pattern of
lights and tone; for example, all
red and green lights flash alter-
nately but the tone does not sound
at all or the tone does not sound
continuously. Another example is
that some red and green lights
flash alternately or the tone
sounds continuously,
Step 2. Unplug the voice terminal on which the trouble appears from its modular
terminal cord and switch it with a working voice terminal (see Figure 4).
The intercom number of the working voice terminal should be five greater
or five less than that of the voice terminal with trouble. (This is done to
make sure your voice terminals are connected to different expansion
modules.) Also, add to your notes the intercom numbers of the voice ter-
minals switched (for example, "voice terminal with trouble-Intercom 10,"
"voice terminal known to be working-Intercom 15").
Basic Trouble Tests
THEN
The voice terminal operation
appears to be normal. Since the
test is inconclusive, go on to the
"General Tests."
Go on to the "General Tests" sec-
tion to see if you need an auxiliary
power unit.
The trouble is caused by either the
voice terminal, control unit, expan-
sion module, or cord/cable connec-
tions between them.
Go on to Step 2.
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