AT&T Merlin 820 Service And Maintenance Manual page 16

Basic Trouble Tests
Plug the cord of the standard telephone into the network interface (out-
Step 4.
side line) on which the trouble appeared and make an outward call using
the standard telephone. (Labels at the network interface or your system
directory will help you find the line with trouble.)
IF
The trouble appears on the stan-
dard telephone and an adapter
(either a two-line or eight-line
adapter) is used at the network
interface,
The trouble appears on the stan-
dard telephone and an adapter
(either a two-line or eight-line
adapter) is not used at the network
interface,
The trouble does not appear on the
standard telephone,
Remove the standard telephone cord from the adapter.
Step 5.
Replace the suspected adapter with one known to be in good working
Step 6.
order, if available. Plug the cord of the standard telephone into the new
adapter and make an outward call.
IF
The trouble appears on the stan-
dard telephone,
The trouble does NOT appear on
the standard telephone,
Page 12
THEN
The trouble is caused by either the
adapter or local telephone com-
pany equipment.
Go on to Step 5.
Trouble found. The trouble is
caused by local telephone company
equipment. Call the local tele-
phone company.
The trouble is caused by your com-
munications system. Go on to the
"Symptom-Based Tests."
THEN
Trouble found. The trouble is
caused by local telephone company
eqipment. Call the local tele-
phone company.
Trouble found. The original
adapter is the cause.
Read the section on Maintenance
Exchange Procedures at the end of
this manual.