TM
11-6130-243-14-3
d. Troubleshooting Chart.
Corrective Measures
Probable trouble
Symptom
Item No.
a.
a.
Check for correct input voltage.
No ac power applied to power supply.
PILOT LIGHT does not light when
1
Replace lamp.
b.
b.
PILOT LIGHT lamp burned out.
CIRCUIT BREAKER is set to ON.
c.
Check C B1, replace if necessary.
CIRCUIT BREAKER CB1 defective.
c.
Open in output circuit.
a.
a.
Check for loose connection, broken lead,
2
No output voltage present.
or faulty component.
b. Replace power transformer T1.
b. Defective power transformer T1.
a. Replace switch S1.
a. Defective switch S1.
Output voltage does not change when
3
b. Replace power transformer T1.
b. Defective power transformer T1.
OUTPUT VOLTAGE ADJUST switch
is turned in a clockwise direction.
a.
Replace defective rectifier.
a.
Defective rectifier CR1 or CR2.
Low output voltage as indicated on
4
b.
b.
VOLTS meter.
a.
Replace VOLTS meter M2.
a.
Defective VOLTS meter M2.
Indication on VOLTS meter differs from
5
b.
Check Cl, replace if necessary.
b.
Defective capacitor Cl.
the voltage measured at the output
terminals using AN/USM-223/U.
a.
a.
6
indication on AMPS meter Ml does
b.
not vary as OUTPUT VOLTAGE AD-
Defective AMPS meter Ml.
b.
Replace AMPS meter Ml.
Defective meter shunt R2.
c.
Replace meter shunt R2.
c.
JUST switch is turned in a clockwise
d.
Adjust or replace potentiometer R3.
d.
Maladjusted meter Ml.
held in ON position.
hold handle to frame.
5-5. General Parts Replacement Techniques
(4) Remove 14 screws and washers holding side
a. Removal of Top Cover. Remove four screws and
panel to frame.
washers from top cover and lift top cover away from
(5) Slide side panel away from handles until
power supply.
clear and then lift away.
b. Removal of Side Panels.
c. Parts Replacement. Power supply parts can be
(1) Remove top cover (a above).
reached and replaced without special procedures after
(2) Remove two screws and washers from center
the top cover and appropriate side panel have been
of side panel.
removed.
(3) Remove two bolts, washers, and nuts which
Section Il. TEST PROCEDURES
testing procedures given in this chapter are listed in a
5-6. General
and b below:
a. Test
procedures are prepared for use by
maintenance shops and service organizations respon-
a. Test Equipment
sible for general support maintenance of electronic
equipment to determine the acceptability of repaired
Nomenclature
NSN
equipment. These procedures set forth specific re-
quirements that repaired equipment must meet
Multimeter AN/USM-33(*)
662500-648-9172
before it is returned to the using organization, A sum-
(RSTS-352B/u)
mary of the performance standards is given in
Dummy Load, Electrical DA 638/U
662500-422-2111
b. Comply with the instructions preceding each
chart before proceeding to the chart. Perform each
b. Tools. All the tools required are included in Tool
step in sequence. Do not vary the sequence. For each
Kit, Electronic Equipment TK105/G and Tool Kit,
step, perform all the actions required in the Control
Electronic Equipment TK101/G.
.
Settings column; then perform each specific test
procedure and verify it against its performance stan-
58. Physical Test and Inspection
dard.
a. Test Equipment and Materials. None Required
5-7. Test Equipment and Tools
b. Test Connections and Conditions. Make sure in-
All test equipment and tools required to perform the
put power line is disconnected.
5-3