TM 11-6625-333-15
DIRECT AND GENERAL SUPPORT MAINTENANCE
across h i g h - v o l t a g e circuits. Severe
burns or electrical shock to the user and
a. The preventive maintenance procedures per-
damage to the equipment under test may
formed at direct and general support categories of
result.
m a i n t e n a n c e a r e actions w h i c h h a v e b e e n
designed to anticipate potential problem areas for
the purpose of correcting a possible trouble before
To be effective, troubleshooting must be system-
it results in equipment outage. The action to be
taken consists mainly of the following:
atic; it will be necessary to perform a sequence of
o p e r a t i o n a l checks, observations, and measure-
( 1 ) Visual inspection of the equipment for
ments before the cause of a trouble is revealed.
the purpose of determining general condition,
u n u s u a l noise, and wear, and observing meter
a. The first step in servicing a defective equip-
indications. Generaily, the equipment will remain
ment is to sectionalize the fault. Sectionalization
operational when these inspections are made.
m e a n s tracing the fault to the major equipment
(2) Repair or replacement of parts that have
component. The second step is to localize the fault.
a definite life expectancy
Localization means tracing the fault to the defec-
tive stage. The third step, isolation, means tracing
b. The direct and general support maintenance
the fault to the defective part. Some faults, such
p r o c e d u r e s are not complete in themselves but
as burned-out resistors, can often be isolated by
supplement the procedures performed at the
sight, smell, or hearing. The majority of faults,
o r g a n i z a t i o n a l category and include any addi-
however, must be isolated by checking voltages,
t i o n a l techniques required to perform mainte-
resistance, and signal levels
nance cm the ME-165/G
b. After the trouble has been sectionalized, per-
f o r m operational tests on the suspected section;
Required
tests serve as a check of the sectionalizing test,
a. The test equipment and materials required
and may also be used to indicate whether or not
f o r maintenance of the ME-165/G are listed in
the unit is functioning properly.
t h e appropriate paragraphs in which the adjust-
m e n t procedures are given. The specified test
equipment, or suitable equivalents, should be used
to comply with the requirements of this chapter.
a. Localizing troubles to a defective part or
circuit in the ME-165/G is accomplished at direct
NOTE
and general support categories of maintenance by
Before using the test equipment, care-
performing the bench test described in d b e l o w
f u l l y read the operating instructions.
u n t i l an abnormal condition is observed, noting
For maximum accuracy in all measure-
the trouble symptom, and performing the related
ments, use the range that will produce a
c h e c k s and corrective measures indicated in the
meter indication as close to midscale as
troubleshooting chart (d b e l o w ) .
possible.
NOTE
h. When using test equipment, place it on a firm
The ME-165/G must be recalibrated
support and position the test equipment so that its
after any repairs or adjustments,
controls are within easy reach.
b. B e n c h t r o u b l e s h o o t i n g
the
ME-165/G
requires the following:
D o N o t allow any test lead to drape
