TM
11-5835-243-34/EE641-AA-MMl-010/E154
MTT/TO
31S3-4-110-1
CHAPTER 3
DIRECT SUPPORT MAINTENANCE INSTRUCTIONS
Section I. GENERAL
specific failure or unserviceable condition and
3-1. Scope
restoring the tape transport to a serviceable con-
This chapter provides maintenance instructions for
dition.
direct support level personnel. Direct support
maintenance is performed by those maintenance
3-2. Voltage Measurements
activities designated to support the using
Voltage, resistance, and continuity measurements
organization and emphasizes corrective main-
are made by direct support maintenance personnel
tenance at the equipment site. Corrective main-
for troubleshooting faults which cannot be resolved
tenance is performed on items which are identified
or repaired by means of the troubleshooting charts.
as faulty by organizational maintenance personnel,
Normally such faults are traceable to wiring or
but are beyond their capability to correct using the
chassis-mounted components. Generally, signal
maintenance resources authorized at the
voltages are at standard TTL logic levels and
organizational maintenance level. Direct support
measurements are made using an oscilloscope.
maintenance personnel also provide technical
Power supply voltages are measured with a
assistance to the using organization in all areas
which require skills and training that are beyond the
capabilities of the organizational maintenance
3-3. Waveforms
personnel. Direct support maintenance activities
All logic levels and waveforms are obtained at the
are described below.
test points located on the front edge of each card.
a. Visual inspection of components for evidence of
potential failure conditions such as lack of
3-4. Verification of Repair
cleanliness, improper seating of connectors, loose
After a fault has been isolated and corrected, the
hardware or other items, discoloration due to ex-
repair must be verified before returning the tape
cessive heat, and frayed cables or wiring. Correction
transport or magnetic tape cartridge to the using
of observed conditions will be accomplished as
organization. Perform the functional tests in
necessary at the time of observance by the main-
tenance personnel authorized to perform the task.
formance of the tape transport, or paragraphs 3-18
b. Replacement of an unserviceable subassembly,
and 3-19 to verify the performance of the magnetic
module, or assembly with a known good
tape cartridge.
subassembly, module or assembly.
c. Performance of the repairs required to correct a
Section II. TOOLS AND EQUIPMENT
3-6. Repair Parts
3-5. Tools and Test Equipment
Tools and test equipment required to perform the
Repair parts authorized for use by direct support
maintenance procedures in this chapter are listed in
maintenance personnel for the tape transport and
magnetic tape cartridge are listed in the Repair
the Maintenance Allocation Chart (MAC) located in
Parts and Special Tools List (RPSTL), TM
TM 11-5805-681-12-1 and TM 11-5805-683-
12-1. Any tools or test equipment authorized for
11-5835-243-34P. Direct support maintenance
use at the organizational level are also authorized
personnel are also authorized to use repair parts
for use by direct support.
listed in TM 11-5835-243-20P.
3-1
