Install guide

ARMY TM 6-6676-308-34
MARINE CORPS TM 08837A-34/2
CHAPTER 3
DIRECT SUPPORT MAINTENANCE INSTRUCTIONS
Section I. GENERAL
3-1. Scope. Direct support maintenance includes repair of
the computer and CDU by circuit card replacement, and
replacement of computer, computer power supply, IMU,
power supply, CDU, and cables. Failed units are forwarded to
general support maintenance.
a. The normal test procedure is to operate PADS and
obtain the built-in-test malfunction indications. The
malfunction symptoms should be furnished by the operator
but can be obtained or verified by maintenance personnel.
Additional testing includes continuity checks and voltage
measurements.
b. Repairs are verified by operating PADS for a period
of time with no malfunctions.
c. The test sequence is summarized in table 3-1 which
references more detailed descriptions of the various
procedure. The system responses are given. When an
abnormal condition is indicated, troubleshoot in accordance
with paragraph 3-9 and perform the specified repairs.
Electrical connections for testing are shown in figure 3-1.
3-1.1. Program Description. The PADS has two unique
memory modules. The older version (core) which is
presently in the process of being phased out and a new
version (solid state) is being phased in. The memory capacity
of the core memory is 32768 (32k) words and the solid state
memory is 65536 (64k) words. During the past few years, the
software has evolved per the user’s request to the point where
the new programs are no longer compatible between the two
memory types. The user willhoweverberequired to use both
memory types until such time as the core memories have
been completely phased out. This will require the manuals to
describe both memory types. The latest version to the
software includes NAVSTAR GLOBAL POSITIONING
SATELLITE (GPS) cueing to the operator. This version also
increases the spheroid repertoire and changes the order of
spheroids. Refer to TM 54675-308-12 for a more detailed
description of the newer software. This newer software is
available in the solid state memory only. Caution must be
exercised in spheroid selection between the two memory
modules.
3-2. Test Setup.
a.
b.
c.
d.
e.
f.
g.
The primary pallet weight exceeds the
normal two-person lift capability. Use
three persons to carry primary pallet into
the work area.
The system must not move during testing.
Place the primary pallet firmly on a solid
workbench, floor, or stable ground outside
the van.
Check that +28V power source is off.
Check that PADS BATTERY and VEHICLE circuit
breakers CB1 and CB2 are OFF.
After PADS has been placed in the work area, check
that the primary pallet components are
interconnected as shown in figure 3–1 and the CDU is
connected to the computer by cable W1.
Check that the cooling system and isolator platform
are not blocked.
Connect battery cable assembly W6 to power supply
connector 3J2.
Check that the polarity of connections to
+28V power source are correct.
Connect power supply connector 3J4 to +28V power
source with cable assembly W211.
The CDU may be
bracket and placed
workbench.
removed from the computer
at a convenient spot on the
Change 6
3-1