2-3. Test Equipment Required for Troubleshooting
2-1. Scope of Depot Troubleshooting
The following chart lists test equipment required for
This chapter covers the troubleshooting procedures
troubleshooting the AN/PRR-9(XE-9). The associated
assigned to the depot category of maintenance for
technical manuals are also listed.
Receiving Set, Radio AN/PRR-9(XE9).
procedures supplement those described in the operation
and organization maintenance manual TM 11-5820-549-
Indicator, Channel Align-
2-2. Organization of Troubleshooting
a. General. The first step in troubleshooting is to
Power Supply PP-3514/U
determine which functions are not operating correctly.
The AN/PRR-9(XE-9) may receive signals satisfactorily,
2-4. Troubleshooting Test Setup
but the squelch may be inoperative. Complaints may
also include weak reception, or completely inoperative
a. Bench tests of the AN/PRR-9(XE-9) require
connection to a power source. The power source must
b. Operational Tests.
Operational tests may
be connected to the AN/PRR-9(XE9) for all dc voltage
indicate the general location of trouble. In many
measurements. The power supply should be set for 3.2
instances, the tests will help determine the exact nature
vdc. TS-352B/U connections are made to pads of the
of the fault. The operational test (TM 11-5820-549-12-1)
printed circuit board in the electronic unit assembly, or
may be used to determine general performance. The
to other points designated in the voltage and resistance
use of Indicator, Channel Alignment ID-1189(XE-2)/PR
chart, paragraph 2-6.d. In making measurements on the
may also help to locate trouble. Some troubles may be
printed circuit pads, always observe the polarity of the
due to poor alinement.
test equipment as specified for the particular tests.
c. Visual Inspection.
Obvious faults such as
broken battery connector pin, and a loose or broken
antenna housing assembly can easily be determined
This equipment contains integrated
from visual inspection.
circuits. If any test equipment item
d. Intermittent Troubles. In all troubleshooting, the
possibility of intermittent troubles should not be
transformer in its power supply
overlooked. If present, this type of trouble often may be
circuit, connect one in the power
made to appear by tapping or gently jarring the
input circuit. A suitable transformer
AN/PRR-9(XE-9) while operating the receiver control.
is identified by FSN 5950-3561779.
The use of higher than normal input voltages for the
purpose of locating intermittent faults should be avoided
since damage to the integrated circuits could result.
(1) Never connect test equipment (other than
multimeters and vtvm's) outputs directly to an integrated
e. Voltage and Resistance Readings. The best
circuit; use a coupling capacitor.
technique for locating trouble is the measurement of dc
voltages and resistances.
The most significant
(2) Make test equipment connections with
measurements on the integrated circuits are the
care so that shorts will not be caused by exposed test
collector terminal voltages. Detailed instructions for
equipment connectors. Tape or sleeve (spaghetti) test
voltages and resistance measurements are provided in
prods or clips as necessary to leave as little exposed as
needed to make contact to the circuit under test.
(3) When a power supply is used in place of
the battery normally used with the equipment,