AT&T Merlin 820 Service And Maintenance Manual page 77

Trouble on More Than One Voice Terminal
Place the control unit On/Off switch in the On position. If an auxiliary
Step 8.
power unit is used, plug it back into the ac outlet.
Using the voice terminal just connected to the Voice Terminals jack
Step 9.
(the voice terminal intercom number will match the Voice Terminals
jack number), try to make an outside call on each of the outside lines. If
necessary, you can refer to your system directory to determine the tele-
phone number that corresponds to each line (A, B, C, D, E, F, G or H).
IF
The trouble appears on a different
outside line,
The trouble appears on the same
outside line as before,
Step 10. Place the control unit On/Off switch in the Off position. If an auxiliary
power unit is used, unplug it from the ac outlet.
Warning: Remove control unit ac power (using the control unit
Step 11. Switch the expansion modules back to their original position.
Step 12. Return all of the modular terminal cords and line cords to their original
position.
Step 13. Return ac power to the control unit.
Step 14. Read the section on Maintenance Exchange Procedures at the end of this
manual to obtain a replacement for the defective component (either con-
trol unit or expansion module).
Page 74
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.
THEN
Trouble found. It is caused by
the expansion module.
Go on to Step 10.
Trouble found. It is caused by
the control unit.
Go on to Step 10.