Voice Terminals Jack Test - AT&T Merlin 820 Service And Maintenance Manual

Trouble on More Than One Voice Terminal
TEST C: 2-LINE/5-TERMINAL EXPANSION MODULE TEST
Do this test only if other tests have determined that the trouble was caused by the
control unit or the expansion module. The trouble must also appear on more than
one voice terminal. Also, you will need more than one expansion module to perform
this test. If you have only one expansion module, call your equipment supplier for
help. Figure 1 shows which lines (A, B, C, etc...) are present on each expansion
module. Also, by matching your voice terminal intercom number with the Voice
Terminals jack number on the control unit, you can use Figure 1 to determine
which voice terminal is connected to which Voice Terminals jack.
Caution: Turning off the power to the control unit will interrupt nor-
mal service to all outside lines.

Voice Terminals Jack Test

Add to your notes the Voice Terminals jack numbers of the jacks on
Step 1.
which the trouble appears.
Caution: If the line cords and terminal cords are not properly
labeled, then you should label them now. Each modular
line cord should be labeled at both ends with the letter
of the Tel. Co. Lines that it is connected. Also, each
modular terminal cord should be labeled at both ends
with the number of the Voice Terminals jack that it is
connected.
Disconnect all of the modular terminal cords and modular line cords from
Step 2.
both the expansion module on which the trouble appears and an expansion
module with no trouble.
Place the control unit On/Off switch in the Off position. If an auxiliary
Step 3.
power unit is used, unplug it from the ac outlet.
Warning: Remove control unit ac power (using the control unit
On/Off switch) before inserting or removing an expan-
sion module. If you are using an auxiliary power unit,
unplug it from the ac outlet.
Step 4. Switch the expansion module on which the trouble appears and the expan-
sion module with no trouble.
Step 5. Connect the modular line cords back into the expansion modules. To
determine where to connect the cords, match the line cord labels to the
Tel. Co. Lines jack letters on the faceplate (see Figure 34).
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