AT&T Merlin 820 Service And Maintenance Manual page 26

Basic Trouble Tests
Step 3. Check to see if the auxiliary power unit is properly connected to the ac
outlet. Then proceed according to the following:
IF
The light comes on,
The light does not come on,
Make sure the ac outlet is supplying power. Do this by plugging a lamp or
Step 4.
radio into the ac outlet.
IF
The ac outlet is supplying power,
The ac outlet is NOT supplying
power,
Step 5. Disconnect the auxiliary power unit from the ac outlet.
Step 6. Disconnect the auxiliary power unit from the control unit.
Plug the control unit power cord into the ac outlet.
Step 7.
Step 8. Perform the action that first revealed the trouble.
IF
The trouble remains,
The trouble no longer appears,
Page 22
THEN
Skip to Step 12.
Go on to Step 4.
THEN
Go on to Step 5.
Trouble found. It is caused by
the ac outlet.
THEN
Go on to Step 9.
Trouble found. It is caused by
the auxiliary power unit. You may
need to disconnect some of your
voice terminals and/or accessories
until the auxiliary power unit can
be replaced.
Read the section on Maintenance
Exchange Procedures at the end of
this manual.