Sample Troubleshooting Problem
To show how troubleshooting documentation is
used to isolate faults, this sample problem is provided
with corresponding fault analysis procedures by using
samples of fault-isolation materials previously cov-
ered in this chapter. The sample problem and asso-
ciated fault analysis procedures are based on a fault
revealed during SMT W-1. It is emphasized that these
are suggested troubleshooting procedures and are not
meant to preclude or remove judgment from the
technician. For the sake of clarity, this problem is
shown as separate steps. Refer to table 1-5 as you
solve this problem.
1. Prior to the hypothetical fault, it is assumed
that all turn-on procedures and preliminary test steps
have been accomplished with no apparent malfunc-
tions indicated. No PERMISSION TO TEST indica-
tion is observed at the radar set console (RSC).
2. After verification of all test setups, the test
coordinator then refers to the FAM for SMT W-1,
which lists all SMT response steps (column 1) and the
associated functions that are tested (column 2).
3. From columns 3 and 4, the sources and inter-
mediate units can readily be determined.
4. Column 5 lists related SMTs.
5. Column 6 lists SFD figure 12-14.1 as the
reference for the permission to test the function. By
using the available reference material, the test coordi-
nator can proceed to column 7 and implement the sug-
gested fault-isolation procedures.
6. In column 7, step 4a, C-TASC (a computer
diagnostic program) is used to determine if logical
output voltages are being (1) generated at the radar
data processor (RDP), and (2) transmitted to the radar
set console (RSC). The succeeding fault-isolation pro-
cedures listed in the FAM are then accomplished as
required until the casualty is found or isolated to an
If the preceding problem had arisen at any time
other than during a scheduled test, the system FID
(see table 1-3) and/or the FCS function directory (see
table 1-4) could have been used.
When the FID is used to facilitate solutions of
problems encountered during normal operations or
weapons system exercises other than scheduled test-
ing, the faulty indication is identified and located in
the Indicator column for the associated equipment
listed in the Equipment column of table 1-3. Using the
same hypothetical fault described above, refer to table
1-3 and locate the RSC in the Equipment column and
PERMISSION TO TEST in the Indicator column. The
applicable SFD and FAM may then be refereed to for
trouble analysis. At the discretion of the test coordi-
nator, the equipment may be setup as required in the
referenced FAM, and the associated trouble analysis
procedures accomplished as described in the above
paragraphs. Where there is no readily identifiable in-
dicator for a given function, reference maybe made to
the SFD to cross-reference the applicable SFD.
Equipment Troubleshooting Documentation
Equipment operating procedures (OPs) contain a
wealth of documentation to enable the rapid localiza-
tion of faults that have been traced to a particular
piece of equipment. The documentation includes (but
is not limited to) fault logic diagrams, signal-flow
diagrams, pyramid diagrams, relay and lamp indexes,
and relay lamp ladder diagrams. In addition, mainte-
nance turn-on procedures, shown in table 1-6, are
provided for energizing the equipment. These pro-
cedures contain references to troubleshooting docu-
ments that are to be used if a given step of the
procedure cannot be performed satisfactorily.