c. Remove the batteries from the SB-22
37. Removal and Replacement
nication Station LS-147(*)/FI
(*)/PT (TM 11-5805-262-12).
d. Disconnect the wires from the binding
a. Remove the power cord connector
posts on the rear of the SB-22(*)/PT.
plug from the INTERCOM power duct
e. Replace the SB-22(*)/PT by the fol-
lowing appropriate procedures in para-
by loosening the captive wingnuts.
c. Disconnect the signal cord from the
39. Removal and Replacement
binding posts on the rear of the LS-147(*)/
d. Remove the LS-147(*)/FI from its
a. Remove the telephone leads from the
TA-312/PT binding posts.
e. Replace the LS-147(*)/FI by following
b. Remove the flathead screw on the side
the procedures in a through d above in the
of the mounting bracket.
c. Lift the TA-312/PT out of the mount-
ing bracket and remove the holding plate
from the buzzer recess on the side of the
38. Removal and Replacement
a. Remove the wingnuts that secure the
d. Remove the batteries from the TA-
312/PT (TM 11-2155).
e. Replace the TA-312/PT by following
raise the retaining bar.
b. Slide the SB-22(*)/PT forward and
remove it from the rack mounting.
Section II. ORGANIZATIONAL, FIELD, AND DEPOT MAINTENANCE
Isolate defective components, parts, or
Note. The maintenance allocation ohart (appx II)
indicates the maintenance functions and tools au-
wiring of the S-183/MSC-31 by making
thorized for each maintenance echelon.
40. Troubleshooting Information
trouble in the power circuits and to figure
a. Procedures for localizing troubles
36 for signal circuits. Repair
within the AN/MSC-31 are given in the
components, parts, or wiring. Use the
equipment performance checklist (para
chart below for references to repair pro-
b. Procedures for troubleshooting com-
ponents, parts, and wiring of the S-183/
c. Procedures for troubleshooting the
major components of the AN/MSC-31 are
given in the applicable technical manuals
f o r removal and replacement of major
41. Troubleshooting and Repair Procedures
Warning: Be extremely careful when
performing the troubleshooting proce-
dures; dangerous voltages are present in