TM 11-5805-386-34/NAVELEX 0967-466-1020
DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE INSTRUCTIONS
Section 1. GENERAL
Polarity reversal may damage transistors or
This chapter contains instructions for isolating
(2) Make sure that shorts are not caused by
troubles to a module, printed wiring board or part
exposed test equipment connections. Tape or
authorized for support at the direct support or
sleeve (spaghetti) test prods or clips to leave
general support. Instructions are provided for
exposed only the area needed to make contact
removal and replacement of parts where the
with the circuit under test.
procedure is not obvious. Direct support main-
d. Resistance Measurements.
tenance is performed on-site in the system con-
are made with the negative probe grounded. Set
the TS-352B/U to RX 100 unless otherwise
a. General Test points, on the rear panel of
specified. Refer to the footnotes at the end of the
each module, are common to many of the printed
wiring board terminals. Check the terminals at
test points first; then, if additional checking is
(2) Refer to the wiring diagrams for point-to-
necessary, refer to paragraphs 2-8 through 2-13
for disassembly instructions for access to the
other terminals on the printed wiring board.
rear panel binding posts.
Module test points are listed as applicable to each
printed wiring board.
b. Test Equipment. T h e m a i n t e n a n c e
allocation chart lists a 20,000 ohms-per-volt meter
Be sure equipment power is off before
removing or reinstalling any module or
TS-352B/U or equivalent for dc voltage and
while taking resistance measurements
in common module.
A N / U S M - 2 8 1 A or equivalent for ac voltage
measurements and for checking waveforms. Refer
to the repair parts and special tools list (RPSTL)
(3) Remove module from equipment for
access to test points and to isolate the module
chart (MAC) in TM 11-5805-388-12.
from shunting resistances.
(4) Resistance measurements chart:
1A1 through 1A3
See footnotes at end of chart.