Maintenance - Bell System Practices 1634 Service Manual

SECTION 502-611-402
3.
MAINTENANCE
3.01
Maintenance of
modular keys is
these components.
handset, dials, ringers, and
outlined in sections covering
3.02
Refer to the appropriate Reference section
in Division .X)2 for replaceable components.
3.03
[mpt-oper operation of 667-type transmitters
may be caused by interference between the
~]rinted circuit board and terminal screw of TBVI
of the cord assembly, This condition can be
corrected by replacing P-180801 .5/16-inch machine
screw \vith P-180800 I/-l-inch binder head machine
screw.
Note: The longer screws
and DxOB cord assemblies.
3.o4
To eliminate mechanical
were used in Dt50B
vibration pickup in
the MN-type transmitter install a "mod;fied
6(;7B transmitter which includes a l-inch vinyl sleeve
\vhich is to be placed over the pivot bar spring.
order as "Transmitter, 667B modified per D-180196."
3.05
steps:
(1)
(~)
(3)
(4)
To remove a defective N 1A ringer from
current production sets complete the following
Remove housing.
Loosen dial mounting plate and move to left.
Disconnect ringer leads.
Remove 3 ringer mounting screws from
underside of baseplate (Fig. 5).
(5) Lift out ringer.
3.06
When an operated pickup key dot's not
remain depressed or release any I)retiousl)
operated key:
(1)
(~)
the
for
mounting screws.
Check that key latch arm is properly illserte(i
in the pivot bar,
Minor adjustment of the key can be n~:~de
by loosening the mounting screws and shit'tin~
key within limits of o~rersized hole provi~ie(i
the mounting screws before ret'ast('ning
(3) If malfunction is related to one key nlo(iuie
test key for proper operation.
Fig. 5-Location of Mounting Screws for N1 A Ringer
Page 14
14 Pages