DIRECT SUPPORT (INTERMEDIATE) MAINTENANCE INSTRUCTIONS
Section I. GENERAL
This chapter provides the information necessary to maintain the processor and detector at the direct support
(intermediate) maintenance level. These instructions are intended to assist the maintenance technician in determining
whether the equipment is operating properly, and if not, to localize the malfunction to the level assigned by the
Maintenance Allocation Chart (MAC) The maintenance information in this chapter includes symptom analysis
procedures, and performance test procedures. The order of presentation of this maintenance information is arranged in
a sequence which is logical in terms of specific maintenance steps required to maintain the processor and detector at the
direct support (intermediate) maintenance level.
a. Detecting faulty operation. The performance test (para 7-11) is provided for use in determining minimum
equipment performance requirements.
b. Locating Trouble. A troubleshooting chart is provided to aid in locating trouble in a minimum amount of time.
The troubleshooting chart (para 7-8) is designed to enable the repairman to locate trouble based on indications obtained
while the processor and detector(s) are operating.
c. Checking Serviceability. Direct support (intermediate) testing procedures designed to check the serviceability of
repaired items of equipment are included in Section V. The test procedure is presented in tabular format.
7-2. Troubleshooting Techniques
To be effective, troubleshooting must by systematic. It is seldom possible to observe a symptom and immediately
diagnose the cause. Usually, it will be necessary to perform a sequence of operational checks, observations, and
measurements before the cause of a trouble is revealed. If the proper sequence is followed, the trouble will be traced
first to a functional unit and then to a defective module. The following four steps should be followed in order to
troubleshoot the equipment effectively and efficiently.
a. History of Equipment. The repairman can obtain helpful information by questioning organizational maintenance
personnel, by reading the complaint notice attached to the equipment, and by reading the equipment log. The more
information the repairman can gather, the more accurate his diagnosis will be and the sooner the trouble can be located
and repairs made.
b. Preliminary Examination A preliminary examination will help in gathering evidence that may lead to the location
of the defect. Symptoms may be obtained by observing the equipment for the following: inadequate surveillance
coverage, abnormal nuisance alarms, discolored components or the presence of smoke by smelling to detect the odor of
burned insulation and parts.
c. Sectionalization. Sectionalization of trouble consists of tracing the trouble to the functional pc board responsible
for the abnormal performance. Use the information obtained from the procedures given in a and b above and the
troubleshooting chart as a quick check in sectionalizing the trouble. Perform each step (or applicable steps) in the
troubleshooting chart to sectionalize the trouble to a pc board or a vibration pickup assembly.
d. Testing After Repairs. After a faulty pc board is located and replaced, the equipment may not be free of faults.
Some other fault (which has not been detected and corrected) may have caused the failure of the part that has been
replaced, or the repairman may have inadvertently caused a trouble. After a pc board or vibration pickup assembly has
been replaced, the equipment should be given an overall performance test (para 7-11) and the results compared with the
performance requirements of the equipment.
Section II. TOOLS AND EQUIPMENT
The tools required for direct support (intermediate) maintenance are contained in TK-105/G.
7-4 Test Equipment
This section provides a list of test equipment (table 7-1) required for direct support (intermediate) maintenance as
authorized by the Maintenance Allocation Chart (MACI Equivalent instruments may be used unless otherwise stated.
The information provided in these tables is not to be used as a basis for requisitioning. For requisitioning test equipment
and repair parts, refer to Repair Parts and Special Tools List (RPSTL), Appendix C.