AT&T Merlin 820 Service And Maintenance Manual page 24

Basic Trouble Tests
Go to a second voice terminal and program the feature on it.
Step 3.
IF
The feature works on the second
voice terminal,
The feature does not work on the
second voice terminal,
Switch the voice terminal on which the trouble appears with a working
Step 4.
voice terminal.
Program the feature on the voice terminal that was working previously
Step 5.
and try it again.
IF
The same trouble remains,
The trouble no longer appears,
Page 20
THEN
The trouble is caused by either the
first voice terminal or the control
unit.
Go on to Step 4.
This test is inconclusive. Go on to
the "General Tests."
THEN
Trouble found. It is caused by
the control unit or the Type I
Feature Cartridge.
Read the section on Maintenance
Exchange Procedures at the end of
this manual.
Trouble found. It is caused by
the first voice terminal.
Read the section on Maintenance
Exchange Procedures at the end of
this manual.