AT&T Merlin 820 Service And Maintenance Manual page 96

Step 10. Plug the substitute extra-alert device into the ac power outlet, if required.
Step 11. Using a voice terminal, dial an outside call to the line with the substitute
extra-alert device.
IF
The substitute extra-alert device
works properly,
The substitute extra-alert device
does not work,
Trouble on an Accessory
THEN
Trouble found. It is the original
extra-alert device.
Read the Maintenance Exchange
Procedures at the end of this
manual.
Trouble found. It is caused by
the control unit or the Type III
Cartridge connected into the con-
trol unit. Reconnect the original
extra-alert device. Then read the
Maintenance Exchange Procedures
at the end of this manual.
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