Bell System Practices TOUCH-A-MATIC 2872A1M Identification, Installation, Connections, Operation, And Maintenance page 23

ISS 5, SECTION503-603-101
(1) 0Disconnect power unit from ac outlet and (9) Install new ringer and assemble in reverse
unplug battery, order. The leads should be routed as shown
in Fig. 3 to prevent contact with the gong and
Note: Removal of ac and battery power subsequent dampening of the ringer output.
results in loss of stored numbers.e
(10) Reassemble set.
(2) Remove key per paragraph 3.18.
(11) 0Reconnect battery and power unit.
(3) Access PSB terminal area per paragraph
3.17. (12) Dial ringback code to test ringer.
(4) Disconnect logic reset leads from PSB (13) Reprogram memory, see Part 5.0
terminals 14 and 29.
(5) Remove the 508-type plugs and (if provided) G. Buzzer
the two contact strips from the back of the
key. 6.08 To replace the buzzer.
(6) Install new key. (1) BDisconnect power unit from ac outlet and
unplug battery.
(7) Reassemble the set.
Note: Removal of ac and battery power
(8) DReconnect battery and power unit. results in loss of stored numbers.0
(9) Test for operation of the logic reset switch (2) Remove the faceplate (paragraph 3.19), and
[paragraph 3.07(7)]. place handset aside.
(10) Reprogram memory, see Part 5.0 (3) Remove upper housing, if provided, [paragraph
3.21(b)].
F. Ringer
(4) Remove the cradle (paragraph 3.20).
6.07 To replace.
(5) Remove the buzzer mounting screw.
(1) BDisconnect power unit from ac outlet and
unplug battery. (6) Remove the mounting screw and spacer for
TB1 (Fig. 3).
Note: Removal of ac and battery power
results in loss of stored numbers.0 (7) Move terminal board TB1 to gain access to
the appropriate terminals on TB2.
(2) Remove the faceplate (paragraph 3.19) and
place handset aside. (8) Remove appropriate leads (Fig. 9H).
(3) Remove upper housing, if provided,[paragraph (9) Reassemble. When replacing TB1, locate
3.21(b)]. its tabs in the slots of the chassis before
refastening the TB1 mounting screw.
(4) Remove the cradle (paragraph 3.20).
(10) jReconnect battery and power unit.
(5) Disconnect the ringer leads (Fig. 9I).
(11) Reprogram memory, see Part 5.0
(6) Tilt the front of the set up.
(7) Loosen ringer mounting screws (Fig. 7). H. Handset Jack
(8) Remove ringer. 6.09 To replace the 616B handset jack.
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